Hi! I have newely build 493 cui stroker engine with Mahle forged flat top pistons with file fit rings, Edelbrock e-street 84cc cylinder heads, Edelbrock rpm intake manifold, comp cam xe275hl camshaft duration 231/237@ 0.050"lift 110 lobeseparation and 106 centerline, Edelbrock 800 avs carburator, Msd pro billet distributor and Msd 6al. The cam break in go good and i have now about 300 miles on the engine and its running great. I just wonder what vacuum readings you should expecting with this setup? Im reading 14 hg/in at idle and that im think is good with this cam? When i do the quick throttle test, give throttle and relise quickly the needle drops fast to 5 hg/in and bounce up to 20 hg/in and falling back to steady 14 hg/in. When you reading about this vacuum test it should drop to under 5 hg/in and bounce up to atleast 25 hg/in and after falling back to steady 17 to 20 hg/in, but thats numbers for stock engins i belive? Other wise this test shows me poor piston rings witch i not belive i have, the engine runs great and not drinking any oil and have no signs of blow by so what should i think about the vacuum readings? Maybe rings arent broken in really yet? Greatful for every though!

 

493 -

You're fine.

Archer

 

Ok that sounds great, thank you for your answer

 

My 500 idles with half that.🙃

 

What you read was for stock engines.... I agree with the group... Your good... And that is a good vacuum number for what you have.

 

Ok, that sounds great, thanks alot for your answer!!

 

Ok maybe you have alot bigger cam than me, i keep the cam down for a good streetable engine, it idles great and have alot of torque, maybe i could have go up a bit with cam but still happy with the engine, it runs great