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I haven't done any testing, but I did calculate somewhere around the 160 psi cranking pressure and 236psi at peak VE. Mind you I have 58º of overlap on the cam

Something wrong if it has 19 degrees at wot up top we run 16 degrees at 21psi with 155psi cranking pressure and could go more if we had better head gaskets. most n/A ones love 28-29 degrees

Nothing wrong, another engine in a racing Gemini with similar specs, 10:1 and a stage 3 crow cam also maxed out at 20º, it did the same, peaked power and max torque at 20º and more only resulted in losses. The dyno doesn't lie. The engine wants what it wants not what you think it should have.

There is no reason that the burn can't be sped up with a good combo to the point of needing less than stock timing.

I'm guessing it's got the cam advanced heaps .this charts from a stock engine with slightly higher than stock duraton cam stock lift due to rules multi angle valve job not allowed porting and stock cast manifolds cause can't use aftermarket headers .took 28 degrees up top pulling 2 degrees cost 10kw adding 2 gained nothing .with a decient cam and compression you should be up near 180-200kw

vlad01 wrote:I haven't done any testing, but I did calculate somewhere around the 160 psi cranking pressure and 236psi at peak VE. Mind you I have 58º of overlap on the cam

Overlap has no effect on cranking pressure, just the static compression and the intake valve closure point. 160psi seems a bit low for a built motor as stock they have more. Test yours and you might be surprised.

We made the same mistake when we rebuilt my mates 454 dialed the cam in advanced compared to how it used to be and went from taking 32 degrees to only taking 22 without detonation and took a lot of work on the spark curve to stop it lpinging getting on the gas and we could no longer run the vacuum advance it would just rattle its tits off lol it also stopped it making the serious top end it used to have.

yeah my cam is pretty small its only 212º at 50 thou and 470 lift, 114 intake center line, lsa of 109.5. It was meant to be a really torquey cam with mild improvements up top. Main areas were low to mid range which it certainly doing what it's meant to.


I have compared both stage 3 crow and wade 992a which both are a tad bigger than my cam but very similar and dyno charts for them are at the 140rwKw with the usual bolt ones included so I can't see how any of this is wrong. Even the gemini race car was in margin of error of my engine, torque, power, specs and timing all in spitting distance of what I got.

Actually I ended up making slightly more than the Gem.

I found it's old dyno chart. It has 10:1 comp, crow stage 3 and fully ported heads. Also liked about 20º of total timing. I recall we tried around 30º but it didn't do much, lost a little bit iirc running that much.

I am sure G can chime in about more of its specs.

Yeah wade cam on 8.5:1 will go 140s-150s maybe a bit more with good headers and exhaust a stock vp will go 125 with headers exhaust and cai and a tune

it could be the dyno you use, the absolute best I ever got from a stock engine with all the bolt ones, good exhaust and headers, CAI etc is 108 rwKw on this dyno. Stock car reads at 90kw on this dyno.