[ponjohn]

Originally Posted by Jay S

With the same cam that this absolutely true. With a well matched cam we have seen very little improvement in performance from the increase from 9.5 to 10. Where we find the gains is when you increase the cam size to match the compression. Then add extra head flow in combination with the bigger cam and head flow and it makes the hp gains much different. Stock heads you can easily run out of cam and head and the compression just makes it miserable to tune.

Cams have compression ceilings where the hp more or less levels out to. We have done many of the 2801 summits type grinds (214/224) profiles, after 9:0 on a 400+ Cid engine size the performance gains we have seen where small. I have had the 204/214 cam in a couple 440 mopars at 8.2 and 9:1. The 8.2 ran every bit as good as the 9. In fact with headers the 8.2 would take the 9:1 engine with manifolds. Lost track of the over 10:1 engines we have done. We keep pushing higher on cam size and head flow to see were the limits are for compression I honestly do not know where it is. My 452 cid fully ported 6x head combo sitting at 10.5 scr with a bullet 300/308, 245/253 @.050 with a 114 lsa, .630/.630. It is a solid roller on a hyd profile. Tim at bullet helped set it up so we can move the lash around to see what the engine is wanting. My biggest effort on a pump gas cast iron headed Pontiac so far in a roller. Biggest solid so far is a 256/264 at .050 w/112LSA solid flat tappet, it would go well into to 10s scr.

Putting these bigger cams with good heads, drag radials and the super eff tight 9.5 converters and you go from keeping up with a Toyota Camry to giveing a Hellcat a run for the money. More fun to beat the Hellcat.

And...how well did they dyno OR run at the track?

I'd rather exchange compression for head flow.

[pastry_chef]

Originally Posted by ponjohn

I'd rather exchange compression for head flow.

I'll take MAF (heads and cam) over compression.

8.2 compression - 567 HP

https://www.hotrod.com/articles/bolt...ome-big-block/

[Jay S]

Originally Posted by ponjohn

And...how well did they dyno OR run at the track?

I'd rather exchange compression for head flow.

Hard to beat head flow.

Good running 454 for 8.2 scr. I have read that article before. Did good for what it was.

Just got the cam last week for that engine mentioned earlier Ponjon.. So I don’t know hp or e.t. yet. Shooting for around 530 hp with the ported stock intake, qjet and ra manifolds. 6x heads are 190cc. I don’t have final flow numbers yet though. Hoping it kind of keeps up with our 510 cid pump gas 69 Charger with 10.50 scr, ported cast iron heads and a big flat tappet mech cam. The Trans Am needs to come close to 11.50 to match my brothers et in the Charger. I think it has a shot. My brother and I have had the charger since 1988.

The dished icon with the 2802 or 60243 Crower looks like a good combo to me transam474. IMHO, no reason to do the flat tops unless the heads cc’s are larger than expected.

[Stan Weiss]

Originally Posted by Jay S

Hard to beat head flow.

Good running 454 for 8.2 scr. I have read that article before. Did good for what it was.

Just got the cam last week for that engine mentioned earlier Ponjon.. So I don’t know hp or e.t. yet. Shooting for around 530 hp with the ported stock intake, qjet and ra manifolds. 6x heads are 190cc. I don’t have final flow numbers yet though. Hoping it kind of keeps up with our 510 cid pump gas 69 Charger with 10.50 scr, ported cast iron heads and a big flat tappet mech cam. The Trans Am needs to come close to 11.50 to match my brothers et in the Charger. I think it has a shot. My brother and I have had the charger since 1988.

The dished icon with the 2802 or 60243 Crower looks like a good combo to me transam474. IMHO, no reason to do the flat tops unless the heads cc’s are larger than expected.

What is the max lift from the Summit 2802? How much of that head flow is above that max lift? After looking at the head flow numbers you might want a cam for more lift.

Stan

[Jay S]

Originally Posted by Stan Weiss

What is the max lift from the Summit 2802? How much of that head flow is above that max lift? After looking at the head flow numbers you might want a cam for more lift.

Stan

All the stock D ports we have had on our flow bench seemed to go turbulent at very close to .5. I have never flowed a 12. Only a 48 for the ra 3. Stan I noticed you had a ram air 3 head listed on your compiled head flows that had a little left after .5. Not sure what it is though, just says ra 3.

Stan has the best head flow compilation across brands I know of.

http://users.erols.com/srweiss/tablehdc.htm#Pontiac


The 2802 does look better with 1.65s. It would be a good candidate for 1.7 rockers too. Not sure how bad it needs them with stock heads. I am pretty sure Summit has the rating wrong, suppose to have 298/308 for the SAE rating, not 298/303, someone got a 8 and a 3 confused somewhere.

[Jay S]

Adding 12 degrees to the crower advertised ratings will get you close to the SAE numbers if you want to compare the crowers to the 2802. The advertised 2802 numbers summit lists are generally numbers someone in sales picked to sell more cams. IRC, subtract 14 degrees on the 2802 SAE numbers to get to Crowers rating at .006. Summit is a lazier cam.

Looks like you have the right idea. See where the compression lands and pick a cam from there.