Thread: Larger engine tames a cam???

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More cubes make a cam more driveable, simply because a larger engine can lose more low-end torque and still have lots left. I had a 283 that'd barely run below 3000 rpm, put the same cam,heads, intake in a 400 and it purred like a kitten full of cream.
For a street cam, less is more. You'll spend more time cruising and less cursing if your cam is a little tamer than the experts recommend. In your Deuce, more power than you'll have there will just spin the tires a few rpm faster, who'll notice?

That sounds like a very healthy combination to me, and a really good engine for street performance. Are you going to have it run on the dyno before you put it in the car? I have a similar combination in my '32 and I am very happy with it.

Originally Posted by rumrumm

That sounds like a very healthy combination to me, and a really good engine for street performance. Are you going to have it run on the dyno before you put it in the car? I have a similar combination in my '32 and I am very happy with it.

.....Yes it's going to be Dyno'ed. I feel more confortable having it all broken in and Dyno'ed before being shipped back to Kansas. Plus if something is wrong with the re build it'll probably let go on the dyno, sort of 'rebuild insurance' if you will...... Plus the last time this motor was built it put out 40 more HP from the first to last Dyno run..... Oh Rumrumm what stall do you have in your '32??? Thanks ;0 Bill

Originally Posted by billlsbird

.....Yes it's going to be Dyno'ed. I feel more confortable having it all broken in and Dyno'ed before being shipped back to Kansas. Plus if something is wrong with the re build it'll probably let go on the dyno, sort of 'rebuild insurance' if you will...... Plus the last time this motor was built it put out 40 more HP from the first to last Dyno run..... Oh Rumrumm what stall do you have in your '32??? Thanks ;0 Bill

I am running a B&M Holeshot 2400 stall in a 700 R4. My 383 has a CompCams Magnum 280 hydraulic (.480/230 @ .050). I wanted to run the XE-274 but it made my DCR too high for pump gas. With AFR 190 heads it dynoed at 450 hp and 468 ft. lbs. of torque. I am very happy with the combination.

.... Rumrumm, Ut oh, an I in trouble??? Quote; " I wanted to run the XE-274 but it made my DCR to high.". Can a small cam change like that change your compression ratio THAT much??? Or is the XE-274 NOT that small of a cam??? But wait, isn't the XE-274 a bigger cam & doesn't a bigger cam lower your compression ratio??? I have the AFR 74 cc heads, what CC are your heads??? Please tell me they are the 68 CC heads!!!
Well you've also got a TQ monster in your '32! In fact, I think I saw pretty much that same combo on the AFR dyno page of their web site? I was going to run the 280 Mag. & then I changed my mind. Everyone except my engine builder recommened a split duration cam. He said that AFR heads flowed so good on the exhaust side that I'd lose TQ with a split duration cam but even AFR disagreed with him. So this REALLY confussed me also....
It looks like are TQ converters are close in stall so I should be good on that one at least..... Thanks for all your help.... Bill

Originally Posted by billlsbird

.... Rumrumm, Ut oh, an I in trouble??? Quote; " I wanted to run the XE-274 but it made my DCR to high.". Can a small cam change like that change your compression ratio THAT much??? Or is the XE-274 NOT that small of a cam??? But wait, isn't the XE-274 a bigger cam & doesn't a bigger cam lower your compression ratio??? I have the AFR 74 cc heads, what CC are your heads??? Please tell me they are the 68 CC heads!!!
Well you've also got a TQ monster in your '32! In fact, I think I saw pretty much that same combo on the AFR dyno page of their web site? I was going to run the 280 Mag. & then I changed my mind. Everyone except my engine builder recommened a split duration cam. He said that AFR heads flowed so good on the exhaust side that I'd lose TQ with a split duration cam but even AFR disagreed with him. So this REALLY confussed me also....
It looks like are TQ converters are close in stall so I should be good on that one at least..... Thanks for all your help.... Bill

Yes, my heads are 68cc heads and I run a static compression of 10.6:1. The Magnum 280 gives me a DCR of 8.46 which is okay with 92 octane, but the XE-274 would have put me at 8.67. Interestingly enough, on the DD Dyno program I was using to choose cams, the XE-274 made a few more hp from 3000-5000 rpm but at 5000 rpm the Magnum 280 caught and surpassed it by 2 hp by 5800 rpm.

Originally Posted by R Pope

More cubes make a cam more driveable, simply because a larger engine can lose more low-end torque and still have lots left. I had a 283 that'd barely run below 3000 rpm, put the same cam,heads, intake in a 400 and it purred like a kitten full of cream.
For a street cam, less is more. You'll spend more time cruising and less cursing if your cam is a little tamer than the experts recommend. In your Deuce, more power than you'll have there will just spin the tires a few rpm faster, who'll notice?

......ah ha, ok now the 'a larger engine will tolerate more cam' thing is making more sense. Going by the principle of "a larger engine can lose more low-end torque and still have lots left", the cam I choice is perfect.... After I posted this last night I went back to my Desk Top Dyno & rechecked the graphs {also checked them against when member S12493H did my engine on his Desk Top, before I had mine} & with the bigger cam it put out 517 Hp @ 6000 & 502 Tq @ 4500 & at 2000 RPM the TQ was 425, and Tq was around 475 till 3500. With the smaller cam, Tq was 475 @ 2000 {50 MORE then with bigger cam}, from 2500 through 5000 it was NEVER below 500 Ft Lbs. {so at least 25 more here}. And max Tq was at 4000 RPM {don't remember exactly, but something like 520}. The only thing it lost was 12 HP at 6000, in fact max HP was @ 5500..... This is BETTER as I will run 12 in wide slicks {legal ones} so more TQ is a good thing ..... THANKS a bunch, Bill