Author Topic: cam specs  (Read 464 times)

Offline fuel749

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cam specs
« on: March 13, 2018, 09:43:59 AM »
Looking for input on cam selection for a stack injected SBC on alcohol. Anybody have any input on things like lobe separation angle, duration etc....

Offline dusterdave173

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Re: cam specs
« Reply #1 on: March 13, 2018, 12:46:26 PM »
I have run two different 355 CI SBC's in my car over a period of time--engines are exactly alike pistons CR etc except cam--first cam was a circle track solid roller I got for $35 used --Isky 255 / 260 at /050 600 lift on a 106 LSA
Ran 5.60 all year long with best of 5.52 or so--Loved it ran wonderful
next engine I used a bigger 270/275 at 050 640 lift on a 108  ran same darn ET and MPH
On paper it should have out run the other but ......
I expect in quarter mile the bigger cam would keep on pulling as my small cam was out of breath at the quarter though it did knock down an 8.90
Now I am adding some nitro been playing with 15% and plan on 20% --Spud says all the cam you can Cram is the answer with the nitro so my next one will be 285 at 050 and for sure a 108 not a 106 just because of the nitro

My experience with drag cars over thirty years went out the window with the dragster
The dragster does not really care about tire pressure it has run great with 5 1/2 and almost the same with 11 lbs  same with two engines and two converters --runs about the same
The nitro REALLY picked things up fast  went to low 5.30's instantly with 15%  have not run quarter with it yet

quarter mile I would stay with the 108

I would say anything around 270-285 at 050 and those will all be 640 lift range will do fine depending on your Cubic Inch   more cubic inch will soak up bigger cam with ease
I have always had a fascination with fast cars at the expense of more normal character development

Offline Frontenginedragsters

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Re: cam specs
« Reply #2 on: March 13, 2018, 07:02:11 PM »
Dave is not far off on his specs.
More information about your parts will help pinpoint closer what to use.
How much gear in the rear and what size tire?
Compression, heads and cubic inch of the engine?
Powerglide and transmission brake?
Are you looking for roller or flat tappet camshaft?
Last year we ran a 355 S.B.Chevy in a 175" WB Front engine dragster.
33" tall tires, 4.11 gear and Powerglide NO Trans Break. Leaving off idle.
Engine was very basic. 10 to 1 compression and un-ported 461 castings.
Enderle stacks on alcohol.
Camshaft was a Engle Flat Tappet Solid. 247*/252* on a 110* lobe separation.
Car ran 5.64 @ 122 MPH in the 1/8
It was assembled as a stepping stone from a Jr Dragster for our youngest son.
We had a ball racing it and won several local races.

Matt Shaff
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« Last Edit: March 13, 2018, 07:20:39 PM by Frontenginedragsters »
Driving a Front Engine Dragster builds character and keeps you awake for a 1/4 mile at a time.

Offline wideopen231

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Re: cam specs
« Reply #3 on: March 19, 2018, 04:29:42 PM »
Roller or flat tappet? How hard do you want to turn it?  All out or mild combo? Compression ratio?
If you get some choices and want I can run them thru desk  top dyno and let you know what it says. Not perfect but its normally dang close.Will need info on motor and number 1 thing is head flow or what you think they are Stan Weiss site has tons listed and can help get you in ball park.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot