A-Series big end weight comparisons - what's best?
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- čas přidán 20. 12. 2018
- Friday tech and today a look at the various crankshaft/conrod big end journal dimensions and the huge differences it can make on a competition engine...
www.med-engineering.co.uk - Auta a dopravní prostředky
I appreciate the time you've taken to put these films together. Very informative.
Very, very interesting.
Factor in a lightened flywheel & clutch ass & a lighter front pulley & that's a huge weight saving 👌🏻👌🏻
So im still learning but would a "perfectly" balanced crank with a connecting rod and piston stop at any position on a set of Parallels instead of dropping straight down? Has anyone had to add weight to the counter balance?
Another way to illustrate this is-
1200 grams = 2.65 pounds of rotating weight- spinning at 8000 rpm = 21,200 pounds of weight the motor is moving in 1 minute. In a 30 minute race that would be 636,000 pounds less weight that your motor is moving compared to a stock rod and crank.
if the crankshaft is milled down to 2.65 (Cooper S), then would a thicker shell/bearing be required? If this is true, then the added weight of the thicker shell must be included in the weight comparison.. very interesting.. wonderful videos..
No, as you would then run a Cooper S type conrod to suit, with the smaller big end journal.
@@MEDEngineeringTechVideos ah.. makes sense. I’m guessing then that the the over con rod arm length is slightly different then… learning all this as I go…
Can you also use this for a road engine? And would it then be drivable?
The multiweb?
@@MEDEngineeringTechVideos Both the pistons and the multiweb yes
@@mmvc1998 Yes, there are a number of these in use on the road. They make a very smooth revving engine.
@@MEDEngineeringTechVideos Good to hear! Thanks for the quick response!
@@MEDEngineeringTechVideos Hello. Are these parts available individually or do they require quantities? Are they manufactured on demand or for specific types of engines?
What RPM are those cranks and rods red lining at?
It's usually limited by the camshaft and head characteristics. Standard cranks we don't recommend going over 7000rpm on a regular basis, these will just keep going.
@@MEDEngineeringTechVideos I use to manufacture and fit a steel centre main. Had a standard one break.
@@duffield55aj yes they can flex quite a lot at higher rpm
1:33 - You lose the overlap between the rod and main journals; care to comment on that compromise?
Unspun weight ? Crank is a rotating assembly including the big end half of the rod small end 1/2 is considered reciprocal.
Steve needs a fucking big joint.