Reliability is NOT an issue with these heads...purchased a set approx 6 years ago to hold the door open to my shop and have never had an issue as they have performed flawlessly!!
If you spent all that money on a door stop!!Instead of a $5 doorstop, don't think I would use your shop,Customers must be paying for your expensive doorstop!!! You opened yourself up on that comment..
You know the BBC well and I learn alot from you on making reliable horsepower, your attention to the details and overall knowledge of the Gen 1 engines is amazing! I agree with others that Procomp heads are not a good investment
I had a set of 049’s you ported,they were a work of art!! I think everyone realizes Speedmaster/Pro Comp heads need a good bit of work. What makes them so attractive on any big block is the saving of ones back😂 Its no joke to go removing an iron big block head in car.
@Car Guy daddyo I've got a set of 1974 990 bbc heads also- have had the larger valves installed etc. No portwork- I'm wanduring how well these will do compared to today's head technology. Have you got any data or info that could help me with ? Thanks
I have these heads, ran 11.5-127mph 1/4 mile in a 4 door sedan, with sealed pro 10cc cast pistons, 240/240 578 camshaft, The kit I brought came with adjustable guide plates.
Glad to hear you like the heads. I bought a set for a 30 over 454 I'm putting in my 69 Camaro. Same pistons as in the video but I'm using a Comp mutha thumper 570 lift. Hope it will run in the mid 11s as well!!
i have used maybe 10 sets of these heads and have not even once had any issues, and will continue to use them. of course i am using new heads but never use adjustable guilds i have never had a problem.
I bought a set of 305cc bbc heads bare....they were for a street rod truck. The quality was pretty good. Took to machine shop they assembled with Manley valves, Comp Cam springs. The only port work was just around the valve seats. I had about 1000.00 into the heads parts labor after all was said. These were bolted on a 454 with a HO cam. I would not take theses heads racing ....but for cruisers they are just the deal
I hope for all the up and comers reading and watching this. You get what you pay for and when you get there do LOTS of research in the area your working
Thanks for doing these videos Mark. I wish you would have done these 14 years ago when i was using big blocks in everything. Now i just put LS turbos in everything.
I’ve used three sets of pro comps, Automatically new valves and set up with comp matching springs to the cams used. only polished intake and ran good numbers with three different cam combos.
I have run two sets of these with 253 and 259 @ .050 and .710 lift on a 106 centerline. Same cubes at 12.0 to 1 static compression with .38 dome and made 762 hp @ 7100. We were under carbed on the test He is way in the hole on the cam.
i did a video on a set of procomp rectangle ports heads after 10 years of use on a drag car. not trying to pimp out my vid but might be worth looking at?
Believe it or not i actually agree with him on this one. I actually think he his understating the issues with pro comp heads. Seat heights and seats barely in the casting (falling out) is another issue. There is very little right about them.The heads are also very thin light weight. Pro comp has an other version with a 360c intake and oval exhaust ports that is a much better part. Much better quality. thicker casting. Seem to be a copy of the old pro action heads? He bashes a much better head like air flow or brodix but he is polite about pro comp?
So I'm assuming these heads aren't worth buying at all, since it probably cost more money for you to fix them than it would to buy a set of trick flows or edelbrock BBC heads, or the new AFR as cast head. What are your thoughts?
The numbers put down on Hot Rod Garage were rather sad as well using these heads. I think they are a fantastic head if you plan to buy them to have them ported. From what I understand they make an impressive cylinder head once worked over. Out of the box however they are barely better than stockers.
Pretty much every independent test I've seen has shown these speedmaster heads aren't very good. It seems the AFR 265's are the best head for fairly short $$. When I say fairly short, I'm considering a good head that's ready to run vs a really cheap head that needs ton's of work and parts before you can put it on the engine.
I'm not a fan of Speedmasters but I think they have a legit place in the market. I'm working out the details on a 460 BBF swap into a 93' F150. All I'm looking for is a torque monster street cruiser. Any used iron heads are going to need a lot of work = money. Name brand alum = Much bigger $$. BBF Speedmasters are at least as good as prepped D0VE's and weigh half as much. I'd love to have a set of Kaase SR-71's... if I can get someone else to pay for them. ;)
U like those rpm intakes?Not trying to question your judgment, but on my flow bench with a 330 cfm edelbrock pontiac ,I lost alot of flow with a rpm intake attached to the heads 30 to 45 depending if upper or lower plenum was flowed.Also noticed that the lower plenum flowed better than upper .You seem totally committed to doing a good job.
I had that exact same set of heads and sold them before trying them because after I researched from other people they said the same thing.They cost too much money for the little gain you get. I stayed with my 781`s.
the shark me too. I stuck with my 781’s that have been worked. The machine shop guy was impressed how they came out after he did the valves and throat cut. I still wonder what these smaller heads give up to AFR’s but happy so far, and they’re paid for.
I even cut a bevel at the top of the block with iron heads. Imagine what the air is hitting coming into the cylinder from those heads. I would want to weld them up and take a cutter to them
Mark, What would you do??? Big Block Chevy 427 Tall Deck, Industrial engine, that has stock FACTORY reverse gear drive, with four bolt mains & steel crankshaft. I learn alot from these videos about a solid reliable Big Blocks. Also like NO music 🎶. Just the facts. Thanks.
I have 496 tall deck big block. Initially I wanted a 9.8 deck height, but when I received my 496 and looked up the casting numbers, i realized that it was a 496 tall deck. It started out as a 427 tall deck truck block. It dropped right in my '68 Impala without any modifications. Headers fitted as well. I only had to put a dent in the header to clear my power steering pump.
@@musclebone7875 To put into a 1972 chevy corvette. I already have Hooker headers with Hooker side mount "mufflers". This was before cats. Will pull the original big block out ( number matching) & save. Will also save the 4 speed Rock crusher, & replace with a manual 5 or 6 speed.
For what it was it wasnt bad considering the mild cam specs. ProComp stuff is expensive garbage. You shouldnt have to go over the heads for the price you pay for them.
He's right , I have the same heads. Purchased from Skipwhite. They did put in really good valves,seats ,guides and retainers.I did put in comp cam springs and my Corvette runs like hell. So ,resumed : The casting is perfect but the original valves ,etc are bull shit. So buy bare heads and put in quality stuff.
You said you got the heads used with worn out guides. Is that why you had to replace everything is because the heads needed rebuilt ? And what CC were these heads advertised to have ? They start at 305 up to 360CC ?
I believe camshaft selection along with the intake choice hurt your HP potential. They were the right choice for a Torquemonster, but with that many cubes a duration in the 240°- 250° range would have suited the build better in terms of HP output. Also, with a cam in the 240° + range a small singleplane would have complimented the build better, if your goal was indeed HP production.
I think you could be right but again if the customer wanted that intake and that particular cam, the customer gets to make those decisions and Mark may have had to work within those parameters. I like what he does with those iron oval ports but the reason a quality aluminum head is so attractive for alot of guys is the shear weight savings off the front end of the car.
@@superkillr hey genius, RPM.. IS how you make hp in a naturally aspirated engine. That's not gonna happen with a dual plane and a 232 @.050 cam in a Big Block Chevy. He blames the combustion chamber ?.. think again.
Seems like pay me now or pay me later, he gets equal or better from his worked cast heads but again not easy to find a set of good/usable heads just collecting dust in someone's garage, sometimes i think a good 502/572 crate engine is the way to go Nicks garage has a good video on someone who bought a BBC SUPPOSEDLY making 600 hp with no dyno sheets/proof and ended up making i think about 350 due to mismatched parts that the engine was assembled with. i would love to see some comparisons of the oval/vs rect. port heads from back in the day
Cheaper is not better,several years I bought a set of brodex aluminum heads for a small block chevy, after installing valve geometry way off. I had to get car running so I left it that way for a couple of weeks before getting back to fix them, in mean time I broke 2 studs while driving,long story short had to redo entire heads new arp studs isky adustable guide plates all new puahrods valve guides and $600.00 dollars later boy what a deal. After redoing motor did not have any issues ran great for years.
I have a question. I rebuilt an 8.1 496. Haven’t started it yet I’m waiting for intake carb push rods and rockets. Bored 30 over. ARP rod bolts. New flat top pistons. Heads cleaned a little exhaust port work. Comp cams springs. My question is when it came to the head gasket the only choice I had was felpro. I noticed a LOT of gap between cylinder walls. Is this ok? Also I noticed had no alignment pins for the heads. So I cleaned the threads. Got new head bolts. Used a little lube on the shoulder and torque to 60. Also I sprayed copper gasket. Honestly I have my fingers crossed and hope it’s dependable. When I torqued my bolts some would torque earlier. Any advice what’s your take on this. Should I buy a better gasket is it worth it.
Truck head question. I have a 366T with 473328 heads. I had an engine vibration. I took heads off and found exhaust valves were mismatched. 3 valves in one head were flat bottom and 1 was concave. The other head had 3 concave and 1 flat bottom exhaust valve. Would the valve shape being different in one cylinder be enough to change compression in that cylinder to cause an engine vibration? Having 1 cylinders valve being different than the other 3? Thanks. I'm wanting to use the 366 truck heads on a 68 396 short block (bored .030). I realize I may have to clearance cut the chamber to clear the #1433 raised dome (9.6 comp). piston. It's for a 58 belair street car. I want small valves and oval ports for good torque. I wont be revving it past 5k if ever.
They were used so you really don’t know much about these heads. Richard Holdner has done videos where he has a lot better results with the new Speedmaster heads.
Hey buddy love your channel! I have a question for you, have you ever come across a leak near the back side of the oil pan next to the flywheel only when revved up, on bbc 454, idling is fine no leaks, I've redone the pan gasket thinking that was it, but still happened, I also added evac system it didn't help
Add a air pressure gauge to the valve covers (0 - 5psi). IF you have blow by at high rpm, it will still pressure the crankcase. Run the car on a chassis Dyno. If you want the best gauge, use a water column, with food dye. This will show positive & negative psi. Water column will show tenths or hundreds of psi. Was the block honed using a Deck plate???? Comment back, want feedback on this theory? Thanks
@@nellyfarnsworth7381 to answer your question, I have no idea, I bought this motor from a part's dealer who said it ran in pink's in a Camaro and that it's a good engine
great video......the guy who owns the motor it probably been cheap to buy good quallity heads to begin with.....?..i know machine work is not cheap....
Bottom line. Spend more money upfront for better quality heads. Save yourself some hassle, and be better off in the long run. Thanks for the video. There is good, and there is cheap, but there is no good, AND cheap.
Hey Mark, don't you have the same issue with AFR heads as far as head gasket? I know when I build my 496ci 4.450 was the size of gasket I had to use, other wise the gasket hung over the combustion chamber. I bought 4.375 and they wouldn't work, so the closest I could get was 4.450 , on a set of magnum 290cc oval port 112cc chambers I used a .030 MLS cometic gasket with the piston .007 in the hole. On a dart big M block
In this build, he mentioned using a Scat 9000 crank. KB/Icon makes stroker pistons for 402 to 434 builds. His massaged 781 heads should wake up a 402/434 I figure. Need to talk to these guys, love the way they do the videos, laid back basic machine work. 620hp/647= 1.327 hp/ci. 434 x 1.327 = 576hp, sounds like fun.
Wow so many commenters still didnt listen to what he had to do . Junk save up and buy some real heads or Marks worked irons Bet the owner spent more in the end than if he bought some afrs. And would make more power for sure. Dont lie to yourself...lol
Btw, it only started leaking when I took it to the track and pushed it hard, I was also told it could be crank flex that would cause the rear main seal to leak under acceleration, your thoughts would be greatly appreciated thanks
@@ApostleDavids8w yup it sucks! Was doing great with all the car shows and stuff, but everyone kept asking, how it does at the track, so I felt if you're going to build it to look like a racer, you'd better race it, and that's where it all started leaking, winter project I guess
maybe but the amount of work they had to make them right still might not even be worth it even if you bought them bare. just buy a performer RPM head retangle port and a weind high rise. proably less work and would bolt on as well with more compression
Doing fixes seem to be the standard thing with pro comp stuff consistency in the casting and machining is always nowhere defiantly better to pay for the US made heads if you don't wanna mess around for average results.
I have a stock 1972 454 in a Corvette original to the car. What heads would you recommend to liven it up some for a weekend racer and a cruise now end then?
The Pro comp/ Speedmaster heads are cast in china but assembled in California. The quality control of the castings is better than the ones cast in the U.S.!
How far 'off' is the factory main bearing bores? Was GM that incompetent that most all speed shop engines need to be Line Honed to make them more accurate?
@@kmcwhq Yes, and how much/where depends on far too many factors to predict. This is where the term 'seasoned block' comes from - a block thats already been run hard for some miles and done most if not all of its distortion, so it stays put after you machine it for performance use.
Why do you say "incompetent?" GM engineers designed two of the most successful production based engines of all time. Let me set you straight.... When you produce hundreds if not thousands of engines per day for 50 to 60 years there will be foundry/ machine/ tooling upper and lower limits. By the way, you've never poured an engine block or a cylinder head etc, etc in your life so how would you know???
@@hilleryclifford2367 Dude, you COMPLETELY missed the entire point of my comment. You better re-read it again several more times to try and comprehend just what I'm saying and if that doesn't help, get someone to 'splain it to you. You need to 'set yourself straight' buddy, and while you're at it, lay off the beers.
Newbie here Is theere a good BBC chevy head out there , Brand ? I have seen some youtubetube videos on how bad Edelbrock heads is out of the box, is there a company out there producing 100 % guality ? have a nice day
When you said the exhaust valve guides were all shot I think I know why. I have a set of these very heads in square port! When I have the geometry right for that 320 cc exhaust valve for 90 degrees at mid lift the 1.7 roller rocker that came in the kit with the heads is on the outside edge (toward the fender) of the top of the valve. If those were kit heads that could be the reason why all of the valve guides for exhaust were shot. My question to you is how do I figure out what back set rocker I would need to correct that issue? The valve top 250 thousands maybe a 32 more. Do I count back from side to center from 1.7 to figure out the back set I would need? I realize this video is old and you might not even see my comment but if you happen to somehow I would really appreciate the help... Thank you in advance, Larry
I enjoy these engine building videos and I have learned a lot of details that make things cook. I am considering doing business with this outfit, does anybody know how to reach them?
@@tailgater2 Thanks for the info...I got the impression they were in Iowa? My 68 impala would like one of those 467's...I assume the experience was positive? Thanks again.
@@tailgater2 I've never had 600 anything, I got virgin 781 heads, hankering to build a big block, plus a couple of 402 blocks I would like to use, plus peanut port heads too. Your endorsement plus the videos make me want to look deeper into VTpro. My 68 impala and 78 Malibu want a rat under the hood, got to talk to mark about what can be done. Thanks again.
Reliability is NOT an issue with these heads...purchased a set approx 6 years ago to hold the door open to my shop and have never had an issue as they have performed flawlessly!!
Yea ok
You spent over $1000 on a doorstop?
@@aubrey5939 Only the best for that man!!!!
If you spent all that money on a door stop!!Instead of a $5 doorstop, don't think I would use your shop,Customers must be paying for your expensive doorstop!!! You opened yourself up on that comment..
@@davidbuddendorf991its a joke. calm down
You know the BBC well and I learn alot from you on making reliable horsepower, your attention to the details and overall knowledge of the Gen 1 engines is amazing! I agree with others that Procomp heads are not a good investment
600+ HP/600ft lb ft from a non-stroked 454....whats wrong with that? Impressive!
I had a set of 049’s you ported,they were a work of art!!
I think everyone realizes Speedmaster/Pro Comp heads need a good bit of work. What makes them so attractive on any big block is the saving of ones back😂 Its no joke to go removing an iron big block head in car.
How much did it cost to have your 049 heads ported?
I love your no BS video's! Nice and to the point while including all the info about each engine. Thanks!
I'll just keep my 088 iron heads! Thanks for sharing your knowledge.👍👍
Brian Samuels you get more hp with those stock?
@@sterlingwitherspoon5709 stock 088 heads will make 630hp with the right combo.
@Car Guy daddyo I've got a set of 1974 990 bbc heads also- have had the larger valves installed etc. No portwork- I'm wanduring how well these will do compared to today's head technology. Have you got any data or info that could help me with ? Thanks
@@moodybluemotorsportsDwneKnos 990 heads are similar to the 088 heads. They make good power in the right setup.
@@moodybluemotorsportsDwneKnosI've seen 680+hp with unported 990s. 748 lift solid roller & 13.5-1 compression. 433ci. That's about the limit tho.
I am putting a set of these heads on a Gen VI 454 new block. Satisfaction with all the positive reviews on CZcams.
Did you finished your build? I bought a set for my 454 and hope they run well.
@@kenshobby5191 It's still in work with all the other builds going on.
I think he’s trying to say , “buy bare heads” and assemble with quality parts. Also see the video on valve seat concentricity....👍
The only problem is the CC issue still exists so you're pumping all kinds of $$$$ into a head that will never be/give 100% anyway
I have these heads, ran 11.5-127mph 1/4 mile in a 4 door sedan, with sealed pro 10cc cast pistons, 240/240 578 camshaft, The kit I brought came with adjustable guide plates.
Glad to hear you like the heads. I bought a set for a 30 over 454 I'm putting in my 69 Camaro. Same pistons as in the video but I'm using a Comp mutha thumper 570 lift. Hope it will run in the mid 11s as well!!
would love to see you do a side by side with AFR 300 heads on a 496 compared to a set of GM ovals that you've worked over.
i have used maybe 10 sets of these heads and have not even once had any issues, and will continue to use them. of course i am using new heads but never use adjustable guilds i have never had a problem.
Glad you like these heads! Bought a set for a 454 I'm putting g in my 69 Camaro
I bought a set bbc , took them to my builder 2 valve needed reseat, been a awesome set
I’d love to see you finish that 620hp 454 from a year or so ago.
I bought a set of 305cc bbc heads bare....they were for a street rod truck. The quality was pretty good. Took to machine shop they assembled with Manley valves, Comp Cam springs. The only port work was just around the valve seats. I had about 1000.00 into the heads parts labor after all was said. These were bolted on a 454 with a HO cam. I would not take theses heads racing ....but for cruisers they are just the deal
I hope for all the up and comers reading and watching this. You get what you pay for and when you get there do LOTS of research in the area your working
Thanks for doing these videos Mark. I wish you would have done these 14 years ago when i was using big blocks in everything. Now i just put LS turbos in everything.
i am a bbf guy but love hearing you talk about rarely found rats in everyday life. big blocks dont daily drive
I’ve used three sets of pro comps, Automatically new valves and set up with comp matching springs to the cams used. only polished intake and ran good numbers with three different cam combos.
I have run two sets of these with 253 and 259 @ .050 and .710 lift on a 106 centerline. Same cubes at 12.0 to 1 static compression with .38 dome and made 762 hp @ 7100. We were under carbed on the test He is way in the hole on the cam.
@@user-yc9qr7ww3r what size motor
I wonder how the Edelbrock aluminum heads compare quality wise versus the Pro Comps? Better geometry and parts?
Edelbrock has one of the finest casting quality on the market
Mark we miss you man, post some videos! I know it's hard to make time for videos when you're so busy.
i did a video on a set of procomp rectangle ports heads after 10 years of use on a drag car. not trying to pimp out my vid but might be worth looking at?
Thanks for sharing that. Was considering those until seeing this video.
Believe it or not i actually agree with him on this one. I actually think he his understating the issues with pro comp heads. Seat heights and seats barely in the casting (falling out) is another issue. There is very little right about them.The heads are also very thin light weight. Pro comp has an other version with a 360c intake and oval exhaust ports that is a much better part. Much better quality. thicker casting. Seem to be a copy of the old pro action heads?
He bashes a much better head like air flow or brodix but he is polite about pro comp?
So much to learn from your videos, even in the photos at the end.
For example, the parallel coolant holes in the block deck surface.
And then spending the same amount as a set of AFR heads after all the machine work, they are ready to perform half as well..
You're alive!!
So I'm assuming these heads aren't worth buying at all, since it probably cost more money for you to fix them than it would to buy a set of trick flows or edelbrock BBC heads, or the new AFR as cast head. What are your thoughts?
Yeah, seems like it. I'm using cheap old iron heads.
You are CORRECT
Ya sounds like it. That’s a lot of extra work from valve guides to push rod guides and combustion chamber work.
so afr heads or kaase heads are paper weights?
There are some vids on here people brought them bare and build them for about 1300-1500
ported factory heads, make my machinist happy?
The numbers put down on Hot Rod Garage were rather sad as well using these heads. I think they are a fantastic head if you plan to buy them to have them ported. From what I understand they make an impressive cylinder head once worked over. Out of the box however they are barely better than stockers.
Pretty much every independent test I've seen has shown these speedmaster heads aren't very good. It seems the AFR 265's are the best head for fairly short $$. When I say fairly short, I'm considering a good head that's ready to run vs a really cheap head that needs ton's of work and parts before you can put it on the engine.
Thank you for giving more specific specs on build especially cam profile
I'm not a fan of Speedmasters but I think they have a legit place in the market. I'm working out the details on a 460 BBF swap into a 93' F150. All I'm looking for is a torque monster street cruiser. Any used iron heads are going to need a lot of work = money. Name brand alum = Much bigger $$. BBF Speedmasters are at least as good as prepped D0VE's and weigh half as much. I'd love to have a set of Kaase SR-71's... if I can get someone else to pay for them. ;)
Haven't been in this game for a while now but knew right away that 600 was low for that much work. Nice looking engine though.
Thanks about the warning ⚠ about China heads.
Stock chevy. L.S. will flow these numbers??
You should probably go watch some more LS videos and leave the bigblock Chevys to the "men".... Do t forget to wear your skinny jeans.
That "extra space" can be made usable as quench area.
U like those rpm intakes?Not trying to question your judgment, but on my flow bench with a 330 cfm edelbrock pontiac ,I lost alot of flow with a rpm intake attached to the heads 30 to 45 depending if upper or lower plenum was flowed.Also noticed that the lower plenum flowed better than upper .You seem totally committed to doing a good job.
I don't care what brand head you buy, I don't buy any of them complete, I load them with my own components so I know what I have when I'm done.
So true!!
Mark
What's your go to head for the 467 BBC setup?
A big block chevy doesn't need aftermarket heads for anything under 700hp.A probably set up OEM 049 or 781 head will support 600+ horsepower.
I had that exact same set of heads and sold them before trying them because after I researched from other people they said the same thing.They cost too much money for the little gain you get. I stayed with my 781`s.
Ozzy yeah I have 781 that are ported. I was wondering the possible gains from a good set of aluminum heads.
the shark me too. I stuck with my 781’s that have been worked. The machine shop guy was impressed how they came out after he did the valves and throat cut. I still wonder what these smaller heads give up to AFR’s but happy so far, and they’re paid for.
7:52 That's dated "Nov 2, 2005 at 20:55:24"
Could I please get one of your time machines? I want to buy some stock.
Run dyno b4 and after mods are done to the heads. Let us see the gaines or losses.
I even cut a bevel at the top of the block with iron heads. Imagine what the air is hitting coming into the cylinder from those heads. I would want to weld them up and take a cutter to them
Sounds to me like a set of 781 heads would be a better bet
Mark, What would you do???
Big Block Chevy 427 Tall Deck, Industrial engine, that has stock FACTORY reverse gear drive, with four bolt mains & steel crankshaft.
I learn alot from these videos about a solid reliable Big Blocks.
Also like NO music 🎶.
Just the facts.
Thanks.
I have 496 tall deck big block. Initially I wanted a 9.8 deck height, but when I received my 496 and looked up the casting numbers, i realized that it was a 496 tall deck. It started out as a 427 tall deck truck block. It dropped right in my '68 Impala without any modifications. Headers fitted as well. I only had to put a dent in the header to clear my power steering pump.
@@musclebone7875
Yes this engine was a grain truck engine. It has a factory G.M. gear drive camshaft (reverse rotation).
@@nellyfarnsworth7381 what do you want to build out of it?
@@musclebone7875
To put into a 1972 chevy corvette. I already have Hooker headers with Hooker side mount "mufflers". This was before cats.
Will pull the original big block out ( number matching) & save. Will also save the 4 speed Rock crusher, & replace with a manual 5 or 6 speed.
@@nellyfarnsworth7381 ok I think it's gonna be a tight fit. I know for a fact you're gonna a 4-inch cowl hood. I'm using a dart single plane intake.
I agree this setup should have made better hp and tq
China Junk
For what it was it wasnt bad considering the mild cam specs. ProComp stuff is expensive garbage. You shouldnt have to go over the heads for the price you pay for them.
He's right , I have the same heads. Purchased from Skipwhite. They did put in really good valves,seats ,guides and retainers.I did put in comp cam springs and my Corvette runs like hell. So ,resumed : The casting is perfect but the original valves ,etc are bull shit. So buy bare heads and put in quality stuff.
You said you got the heads used with worn out guides. Is that why you had to replace everything is because the heads needed rebuilt ? And what CC were these heads advertised to have ? They start at 305 up to 360CC ?
I believe camshaft selection along with the intake choice hurt your HP potential. They were the right choice for a Torquemonster, but with that many cubes a duration in the 240°- 250° range would have suited the build better in terms of HP output. Also, with a cam in the 240° + range a small singleplane would have complimented the build better, if your goal was indeed HP production.
I think you could be right but again if the customer wanted that intake and that particular cam, the customer gets to make those decisions and Mark may have had to work within those parameters. I like what he does with those iron oval ports but the reason a quality aluminum head is so attractive for alot of guys is the shear weight savings off the front end of the car.
who woulda thought.. bigger cam more horsepowers... and spin and spin till all the parts fly out. Thanks for the obvious.
@@superkillr hey genius, RPM.. IS how you make hp in a naturally aspirated engine. That's not gonna happen with a dual plane and a 232 @.050 cam in a Big Block Chevy. He blames the combustion chamber ?.. think again.
Seems like pay me now or pay me later, he gets equal or better from his worked cast heads but again not easy to find a set of good/usable heads just collecting dust in someone's garage, sometimes i think a good 502/572 crate engine is the way to go
Nicks garage has a good video on someone who bought a BBC SUPPOSEDLY making 600 hp with no dyno sheets/proof and ended up making i think about 350 due to mismatched parts that the engine was assembled with. i would love to see some comparisons of the oval/vs rect. port heads from back in the day
Cheaper is not better,several years I bought a set of brodex aluminum heads for a small block chevy, after installing valve geometry way off. I had to get car running so I left it that way for a couple of weeks before getting back to fix them, in mean time I broke 2 studs while driving,long story short had to redo entire heads new arp studs isky adustable guide plates all new puahrods valve guides and $600.00 dollars later boy what a deal. After redoing motor did not have any issues ran great for years.
Excellent video thank you bro
I have a question. I rebuilt an 8.1 496. Haven’t started it yet I’m waiting for intake carb push rods and rockets. Bored 30 over. ARP rod bolts. New flat top pistons.
Heads cleaned a little exhaust port work. Comp cams springs.
My question is when it came to the head gasket the only choice I had was felpro. I noticed a LOT of gap between cylinder walls. Is this ok?
Also I noticed had no alignment pins for the heads.
So I cleaned the threads. Got new head bolts. Used a little lube on the shoulder and torque to 60. Also I sprayed copper gasket.
Honestly I have my fingers crossed and hope it’s dependable. When I torqued my bolts some would torque earlier.
Any advice what’s your take on this. Should I buy a better gasket is it worth it.
Truck head question. I have a 366T with 473328 heads. I had an engine vibration. I took heads off and found exhaust valves were mismatched. 3 valves in one head were flat bottom and 1 was concave. The other head had 3 concave and 1 flat bottom exhaust valve. Would the valve shape being different in one cylinder be enough to change compression in that cylinder to cause an engine vibration? Having 1 cylinders valve being different than the other 3? Thanks. I'm wanting to use the 366 truck heads on a 68 396 short block (bored .030). I realize I may have to clearance cut the chamber to clear the #1433 raised dome (9.6 comp). piston. It's for a 58 belair street car. I want small valves and oval ports for good torque. I wont be revving it past 5k if ever.
Get a set of Brodix BB-2 plus heads bare and have them blueprinted with top shelf parts for your 427-496 rat.
They were used so you really don’t know much about these heads. Richard Holdner has done videos where he has a lot better results with the new Speedmaster heads.
A used head that was fully worked over by a very good builder. I would say he knows everything about them.
Hey buddy love your channel! I have a question for you, have you ever come across a leak near the back side of the oil pan next to the flywheel only when revved up, on bbc 454, idling is fine no leaks, I've redone the pan gasket thinking that was it, but still happened, I also added evac system it didn't help
Add a air pressure gauge to the valve covers (0 - 5psi). IF you have blow by at high rpm, it will still pressure the crankcase. Run the car on a chassis Dyno.
If you want the best gauge, use a water column, with food dye.
This will show positive & negative psi. Water column will show tenths or hundreds of psi.
Was the block honed using a Deck plate????
Comment back, want feedback on this theory?
Thanks
@@nellyfarnsworth7381 to answer your question, I have no idea, I bought this motor from a part's dealer who said it ran in pink's in a Camaro and that it's a good engine
@@ratgasgarage
Another guess, engine is overbored (too much) cylinder walls are Thin, and Not sesling at high rpm.
Do have a pcv valve on your values covers
Do you have a pcv on your valve covers that's for crane case ventilation
I wonder how a set of your ported 781 heads would be vs. this set?
I 2nd that.
I’m looking for the same answer. My 781 heads are ports with comp cams springs
He build damn near same engine with 781’s. It’s the 620 hp 467 vid series.
The 781’s picked up 30-40 cfm after he ported them.
great video......the guy who owns the motor it probably been cheap to buy good quallity heads to begin with.....?..i know machine work is not cheap....
Bottom line. Spend more money upfront for better quality heads. Save yourself some hassle, and be better off in the long run. Thanks for the video. There is good, and there is cheap, but there is no good, AND cheap.
Hey Mark, don't you have the same issue with AFR heads as far as head gasket?
I know when I build my 496ci
4.450 was the size of gasket I had to use, other wise the gasket hung over the combustion chamber.
I bought 4.375 and they wouldn't work, so the closest I could get was 4.450 , on a set of magnum 290cc oval port 112cc chambers
I used a .030 MLS cometic gasket with the piston .007 in the hole.
On a dart big M block
In this build, he mentioned using a Scat 9000 crank. KB/Icon makes stroker pistons for 402 to 434 builds. His massaged 781 heads should wake up a 402/434 I figure. Need to talk to these guys, love the way they do the videos, laid back basic machine work. 620hp/647= 1.327 hp/ci.
434 x 1.327 = 576hp, sounds like fun.
#14081045 bbc head flow #. Have u ever ported this head for more flow. Thanks
Wow so many commenters still didnt listen to what he had to do .
Junk save up and buy some real heads or Marks worked irons
Bet the owner spent more in the end than if he bought some afrs. And would make more power for sure. Dont lie to yourself...lol
Btw, it only started leaking when I took it to the track and pushed it hard, I was also told it could be crank flex that would cause the rear main seal to leak under acceleration, your thoughts would be greatly appreciated thanks
Man that sucks to hear all that work and it leaks.
@@ApostleDavids8w yup it sucks! Was doing great with all the car shows and stuff, but everyone kept asking, how it does at the track, so I felt if you're going to build it to look like a racer, you'd better race it, and that's where it all started leaking, winter project I guess
Rat gas Garage ya another good winter project to make her bulletproof 👍
I need one for mr 2012 Silerado 4x4.
LOL
Any chance performance engine building could test AFR eliminator bbc heads sometime?
Yes but couldn't the moral to the story also be use a Bigger Bore sized motor like 572 or 540 ??
maybe but the amount of work they had to make them right still might not even be worth it even if you bought them bare. just buy a performer RPM head retangle port and a weind high rise. proably less work and would bolt on as well with more compression
Doing fixes seem to be the standard thing with pro comp stuff consistency in the casting and machining is always nowhere defiantly better to pay for the US made heads if you don't wanna mess around for average results.
Why not go with 110cc chamber? I am trying to learn the offset of velocity vs size.
Not a fan of these heads. But to compare to the cast iron's they ran before Aluminum needs a full point of compression to compete.
I have a stock 1972 454 in a Corvette original to the car. What heads would you recommend to liven it up some for a weekend racer and a cruise now end then?
it’s Scott Timms
Will pro comp heads be a decent replacement for smog heads on a really mild build.
It's not gonna be a really hot engine
Let's do 427 bbc next.
The Pro comp/ Speedmaster heads are cast in china but assembled in California. The quality control of the castings is better than the ones cast in the U.S.!
So... buy procomps bare [if you must], then burn the "savings" on machine shop work just to get at decent hardware. Nothings free.
He's just being picky, they are definitely worth saving 2k over name brands
Hi have you already made a strong engine with Vauxhall?
I never heard it shift into second gear.😜
How far 'off' is the factory main bearing bores? Was GM that incompetent that most all speed shop engines need to be Line Honed to make them more accurate?
Between that and cast irons movement over time, the short answer is yes.
@@thenewBH And which way does the cast iron move? Out of round? Do the bores change location in the block?
@@kmcwhq Yes, and how much/where depends on far too many factors to predict. This is where the term 'seasoned block' comes from - a block thats already been run hard for some miles and done most if not all of its distortion, so it stays put after you machine it for performance use.
Why do you say "incompetent?" GM engineers designed two of the most successful production based engines of all time. Let me set you straight.... When you produce hundreds if not thousands of engines per day for 50 to 60 years there will be foundry/ machine/ tooling upper and lower limits. By the way, you've never poured an engine block or a cylinder head etc, etc in your life so how would you know???
@@hilleryclifford2367 Dude, you COMPLETELY missed the entire point of my comment. You better re-read it again several more times to try and comprehend just what I'm saying and if that doesn't help, get someone to 'splain it to you. You need to 'set yourself straight' buddy, and while you're at it, lay off the beers.
Are y’all still in business, I would like to purchase a motor.
How much more power would a 106 LSA make?
Newbie here Is theere a good BBC chevy head out there , Brand ? I have seen some youtubetube videos on how bad Edelbrock heads is
out of the box, is there a company out there producing 100 % guality ? have a nice day
AFR best on the market
When you said the exhaust valve guides were all shot I think I know why. I have a set of these very heads in square port! When I have the geometry right for that 320 cc exhaust valve for 90 degrees at mid lift the 1.7 roller rocker that came in the kit with the heads is on the outside edge (toward the fender) of the top of the valve. If those were kit heads that could be the reason why all of the valve guides for exhaust were shot. My question to you is how do I figure out what back set rocker I would need to correct that issue? The valve top 250 thousands maybe a 32 more. Do I count back from side to center from 1.7 to figure out the back set I would need? I realize this video is old and you might not even see my comment but if you happen to somehow I would really appreciate the help...
Thank you in advance,
Larry
Pro maxxx is a much better budget head.
Why don't you put a real cam in there and test it ? That little one isn't going to do anything.
Doesn’t like China heads but uses China crankshaft?? Isn’t a scat crank made overseas???
I enjoy these engine building videos and I have learned a lot of details that make things cook.
I am considering doing business with this outfit, does anybody know how to reach them?
Vortecpro in Colorado Springs. I have one of Mark’s 467’s, it’s a screamer.
@@tailgater2 Thanks for the info...I got the impression they were in Iowa?
My 68 impala would like one of those 467's...I assume the experience was positive? Thanks again.
@mike f I visited Mark’s shop to pick up my engine, very good experience. I run it hard, no problems at all, 600hp 600lb/ft all roller. It’s a blast.
@@tailgater2 I've never had 600 anything, I got virgin 781 heads, hankering to build a big block, plus a couple of 402 blocks I would like to use, plus peanut port heads too. Your endorsement plus the videos make me want to look deeper into VTpro. My 68 impala and 78 Malibu want a rat under the hood, got to talk to mark about what can be done. Thanks again.
Talking about heads without you having a hat on is distracting
Where os your place of business and contact info please... thank you
469 ?
Jonesssssss
Buy quality heads not cheap junk like speedmaster/pro comp junk
Chinese basher
Chinese junk.
This guy talks to much