GM 781 Cylinder Head Prep and Overview 620+ HP Street/Strip 454 Big Block Chevy
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- čas přidán 3. 04. 2018
- Part 11 - GM 781 Cylinder Head Prep and Overview
-In Depth Performance Engine Build
620+ Horse Power Street/Strip Pump Gas 454 Big Block Chevy - Auta a dopravní prostředky
not all machine shops are created equally. good work
Thanks for taking the time to make these vids!
Appreciate this series and education! Thank you
Thanks so much for doing these videos. As a Tool and Die maker for 40 yrs I appreciate the explainations and details.
I really miss your videos! I really wish you would produce more
I really enjoyed my visits to the shoppe in C Spgs. The famous CART!!!
From the looks of that table it kinda gives you an idea of how heavy big block chevy heads are.
lol
I didn't even notice until I read your comment😂
any reason you are sticking with the 3/8 stem valve?
What’s your thought on the 454 gen 5. I’ve read the gen 5 block was crap. 454 are pricey and I found one at a U-pull it yard for 250 complete but it’s a gen 5
Never had a problem with a ft can in a bb. GM even used them in the 90s .
Dont need a mega huge roller to make power in these engines.
Just saw your hate mail video funny just looking at the work table tells tale of alot of time work expierence it looks like 1000s of heads have been on there thanks laugh 😆 education
Are these the same as the 049 heads...
I have a bbc 572 that I want to make 1000 hp I have some assault heads 345cc will I make 1000hp with these heads
My BBC heads have 239 stamped under the head where I've seen in other videos 781 or 049 what does this mean what heads do I have
I don't recognize that casting number, it's probably a peanut port truck head made for low rev torque. For an oval port 049 or 781 is about the only way to go unless you want a closed chamber head.
When you un-shroud the valves you install the head on the block reach up inside and scribe the bore on the gasket surface. you do not use the gasket or any marks left from the gasket.Then you hand shape the chamber to the marks. Counter boring with a guide machine is just a quick and dirty way to GET $$$ if you use the gasket you will have the bore edge hurting the flow and also the potential for hot spots. The marks from the gasket and the seat wear show this casting has had a hard life would not be my first choice.
YOU ALWAYS DO GUIDE WORK IN A GUIDE AND SEAT MACHINE YOU NEVER HAND BORE OR REAM with a hand held drill The sunnen machine he has is ok for seat cutting (If you know how to use it)but not so good for guide work its slow and clumsy. When sunnen wanted to make guide machines they bought out tobin arc and did some minor updates . The design is from the 50's
Tom Hutchins, what's your experience?, where is your shop or who do you work for building engines?, how many engines have your built and for whom? Enlighten us.
@@olderthanyoucali8512 from your screen name your obviously an idiot. Cali? we are all Americans you ignorant inbred fool trying to start a pissing match over a tech comment that is a year old? Now crawl back in your single wide and brush your tooth.
Marks engines run quite well.
Partly due to valve seat concentricity, This is achieved with good guides and straight pilots and that old machine in the videos.
Where is your shop located?
I dont like bronze valve guides take a drill press and try to drill bronze it will grab the drill bit and if it looses lubrication it can also grab a valve thefore causing piston hit the valve and bending valve and busting piston
Why are you going with flat tappet rather than roller?
Probably $$$$$$$$$$$$$
Yeah, it's a money thing. That lift number is really mild for a BBC and it's hard to imagine he's even leaving 20hp on the table over a solid roller considering the heads, but he could be saving 1k in cost considering going to a roller cam adds some to the cost of nearly every part on a BBC and can add machine work depending on the block.
Hey Mark , where is your shop located ?
Colorado Springs, I believe.
Josh Dais ok thanks !
BBC eats flat tappet cams! I know, I ate 2 of them. Hydraulic roller far better
not true!
They require a specific break in procedure.... what did you do? Start it up and drive to the gas station immediately 😆
@@jasoncardoza6375 have you ever built one with a large flat tappet cam with mega spring pressure? Brian is right, we have lost a couple cams in BBC and we always use break-in oil AND zinc additives.
Jess Roberts first off, what part of “specific break in procedure “ don’t you understand? It includes proper oils, pre checking oil pressure by manually priming it etc. if everything is properly done, rarely a Cam will flatten and in those rare cases it is a defective camshaft. (Highly unlikely) second, I was busting his balls too. Car guy antics. So stfu man I’m not a CZcams “car expert “ yes I’ve built engines starting from above stock 355 Chevy (because just reringing and a home job is a lazy mans way) having it completely machined and rebuilding it to performance 383 and 496 strokers. Currently I’m on a 440 build. I’ve messed up a lot of things but I am man enough y admit I messed up and miss calculated. It only takes just a few thousandths off to create damage. So again man stfu
@@jasoncardoza6375 when brand new BBC engines are wiping cam lobes. I'd say it's a problem.
runnin a flat tappet?!!!!!
Mahle being a German word is pronounced like 'Allah', like Mallah...i finally called the factory and asked how it was supposed to be pronounced and this is what they told me.
I would never buy anything from this dude or have him do any machining. I have you heard some of his comments about selling parts that they have checked out and are known to be bad and flawed but yet they will "put them on craigslist". Very shady indeed.
This guys in another world . You never remove the guides on a BB chevy head they go trough the water jacket and will leak. Also the guide is not concentric because it is inserted then finish bored for alignment at the factory the example he is showing is an extreme case.
Are you sure about this Tommy??
Lol every bbc valve guide I've done was the intakes and nope no water
The exhaust guide is the one in the water jacket.
Your actually responding to 5 year old posts? Your a lonely boy aren't you? Note the guy in the video stopped posting ? Intake exhaust you never pull iron oem BB Chevy guides. @@jerrylauber7311