dyno numbers--Suggestions??

thehueypilot · Oct 16, 2006

cola8d8 said:
They are the stock AFR valve springs, maybe I need to change those....
I dont remember what rockers they are but they were blue.

Dark Night, do you think the stock AFR valve springs with that cam might be what is causing the low power and flat power curve? It is kind of a lot of work to change them but could get me on the right track.

My AFR heads came standard with solid roller cam springs (210#'s) so if you are running a hyd roller the seat pressure is way too much. It cost me extra to have them change them to a 120 lbs seat pressure springs for my AFR 225's. Your hyd lifters could be collapsing because of the higher spring pressure.

304billet · Oct 16, 2006

Anytime u change heads u need to check the pushrod length with a pushrod checker.

Second, don't even consider the AFR 185's, they will not clear P/V, and AFR will tell u that. and that shop does not know what they r talking about. The only head that will clear, r the AFR 165's and TFS TW or Track Heat.

First, get the correct pushrods. If u don't u run the risk of premature head life because of bad valvetrain geometry.

Second, do a leakdown test to see where ur how much compression is slipping by the rings. S/B between 2%-10% leakdown on all cylinders for a street engine. anymore than 10% time for a refresh, IMO.

u s/b closer to 300/300 @ the RW, NA especially because of that big X cam. ur valve train geometry fix is not going to give u 50rwhp.

cola8d8 · Oct 16, 2006

should I step up to the TFS track heat intake (or other) instead of the street heat intake??

Also these two pulls were made about 10 mins after driving the car 100+ miles to the shop... if that matters.

cola8d8 · Oct 18, 2006

Thanks 304billet , I am pretty sure the push rods are correct. I am going to do a leak down test this weekend and post the results. I am also remembering something wierd about the intake gaskets maybe being too small(was 2 years ago)... I am going to pull the intake off and check the gaskets also.

klapdout · Oct 18, 2006

304billet said:
Anytime u change heads u need to check the pushrod length with a pushrod checker.

Second, don't even consider the AFR 185's, they will not clear P/V, and AFR will tell u that. and that shop does not know what they r talking about. The only head that will clear, r the AFR 165's and TFS TW or Track Heat.

First, get the correct pushrods. If u don't u run the risk of premature head life because of bad valvetrain geometry.

Second, do a leakdown test to see where ur how much compression is slipping by the rings. S/B between 2%-10% leakdown on all cylinders for a street engine. anymore than 10% time for a refresh, IMO.

u s/b closer to 300/300 @ the RW, NA especially because of that big X cam. ur valve train geometry fix is not going to give u 50rwhp.

+1

i wouldnt go back to that shop, if they dont know very basic head theory id never trust them tuning my car

also there dyno could be out of calibration, they could have not used SAE correction, or used alot of smoothing, all of which can add up to low numbers

dyno numbers--Suggestions??

thehueypilot

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dyno numbers--Suggestions??

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