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is this to much cam...?

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350 camshaft
25K views 23 replies 9 participants last post by  mud.man.rj 
#1 ·
ok building a mild 350 motor for a daily driver for a buddy.... he has a set of 2.02 heads and a stock bottom end 350... the heads have been millied for more compresion... the motor is going in a 89 1/2 ton truck.... this is a cam i found would it be to big ...if so what would be a good pick.... he was very spacific on wanting it to sound radical... ( i tryed to explain it would suck to drive) but i will do what he wants.....

CAMSHAFT SPECIFICATIONS
Valve Lift -- Int."/Exh." .488/.509

.050" Duration -- Int./Exh. 234/244

Lobe Seperation Angle 107/117
 
#4 ·
cam

A lot of cam manufacturers offer retro "sounding" cams that work well.They are similar to the old GM 350 hp 350 cam. Use a hydraulic flat tappit cam for that lumpier idle.With stock compression a 106 degree intake centre line have a bumpier idle compared to 110 or 112. 450 lift is probably enough.really depends on how high you want to rev ,,,use headers on this application as stock manifolds seem to tame the cams sound a little.270 ish advertised duration is plenty
 
#10 · (Edited)
78 monte beat me, I was gonna suggest the same cam. The same grind is available as the Crane 274HO6 grind 274HO6 cam/lifters at Summit Racing, the Summit K00172 (supplied to Summit by Crane) Summit Racing SUM-1785 cam (K00172 cam & lifter kit) at SummitRacing.com, and the Elgin CL1785PK Cam/lifter kit at Northern Auto Parts Elgin CL1785PK at Northern Auto Parts. This grind, with it's tight 106* lobe spacing angle, has a pretty rough idle, Crane lists the powerband as 1800-5400. Crane states this cam is good for 8.75:1 - 10:1 compression ratios.

Kenny, this cam may satisfy your buddy's "cam music" desire and still give good performance. Here's some YouTube videos of this grind:





 
#12 ·
"bigger is always better" :nono:


since i'm guessing that they are stock smog style heads that have been milled down for more compression, I would say that there is no point in going over .450-.470" lift max on this motor cause the heads wont support any higher of a lift. as mentioned tighening up the LSA on the cam will give it a choppier idle, a would recomend a cam in the 220° @ .050 range with around .440-.460" and a 108LSA. matched with some headers and 2.5" exhaust and some 2 chamber mufflers, I recomend the Thrush welded mufflers (i use them on my truck, and i've had a lot of complements). a 600-650 vac secondary carb will do fine or if you can find one and know what you are doing then go for an older 750 Q-jet. He will have a lumpy idle but it wont be crazy. the problem i see here is that even though he will have a lumpy idle he still wont likely have over 250-280hp due to the heads. so my near stock GMC 2500 with the 340hp (factory) 6.0L will still hurt him.

*for a decent performing and sounding motor you will need to change the heads*
 
#14 ·
yup, that would be a decent cam

Isky Racing Cams 201271 - Isky Hydraulic Flat Tappet Camshafts - Overview - SummitRacing.com

it would have a decent idle, it's kinda of on the boarder with whether it would need a higher speed stall converter or not. i think you could get away with a stock converter. but if it where my project i would put a 2500-2600 stall in it. and if you are running anyting larger than a 30-31" tall tire then i would recomend atleast 4.10 gears. epecially since the truck should have a 700r4 in it.

before you go and order that cam you will want to check and see if the stock heads w/ what ever springs, stock or aftermarket can handle .465" lift. I personally think it will need new springs and shims because i would want around .050" before i got into any kind of coil bind issues, so you would be looking at a set up that had atleast .500-.525" coil spring depression in to it before bind. not to mention you will have to look into what seat pressure ISKY recomends for this cam and match that too.

i still think that another set of heads would be a worth while (even money wise) purchase. the problem is that you have set your self up with those domed pistons so you will have to go with around a 70-72cc combustion chamber heads to get your compression levels down to a decent level.

may i ask why you went with a .015" shim gasket? I hope that it wasn't for more compression cause you could very well end up with some bent valves pretty fast if everything else doesn't check out.
 
#16 ·
cam/overlap

Having the 106lsa and a lot of overlap can be used if everything else is setup right, especially with some stall to get it into the useable range, but for a turbo or twin turbo app. you can't use a lot of overlap due to the fact that you are pressurizing the intake charge and will push cylinder pressure out the exh. ahead of time, naturaly asperated won't as bad, so have to stick with a smoother idle, but power galore. Why such a tall rear gear ratio, man sounds like 200mph with a 2.73, the turbo's would come in a lot quicker with a better ratio like 3.42's and won't need too much stall either.
 
#17 ·
Having the 106lsa and a lot of overlap can be used if everything else is setup right, especially with some stall to get it into the useable range, but for a turbo or twin turbo app. you can't use a lot of overlap due to the fact that you are pressurizing the intake charge and will push cylinder pressure out the exh. ahead of time, naturaly asperated won't as bad, so have to stick with a smoother idle, but power galore. Why such a tall rear gear ratio, man sounds like 200mph with a 2.73, the turbo's would come in a lot quicker with a better ratio like 3.42's and won't need too much stall either.
turbos come in off idle and pull all the way to my 5,500 rpm limit
and yes i plan on doing 200 mph with it down at the salt flats this year just need to get some more saftey equipment before the car is legal to go that fast on the salt.

not to mention the speedlimit on the highways here is 80mph and ill be dailing driving this car for the most part, and i make a few 120 mile round trips a week. so want to keep the low gears for milage
 
#18 ·
Man, 80mph there, nice, real nice. I bet there is a whole sh@t load of safety equip for running that fast, can see why the 2.73's then, makes sense. Have never done that, but used to go on road trips on our Northern highway's at 150mph for extended periods on 3 different street bikes I had when younger, glad to live past that, but was fun, so doing it leagally on the salt would be pretty sweet.:thumbup:
 
#20 ·
9.0's

So at 9.0's you must be fully caged and what 5 point harness, how about fire system for either is it needed too, not for 9.0's but what about the Mph on salt. have you ever raced on the salt at all and if not do you start in the lowest class and work your way up to be legal each time, i imagine a lot of diff classes too. what else is done on your build, suspension too.
 
#21 ·
So at 9.0's you must be fully caged and what 5 point harness, how about fire system for either is it needed too, not for 9.0's but what about the Mph on salt. have you ever raced on the salt at all and if not do you start in the lowest class and work your way up to be legal each time, i imagine a lot of diff classes too. what else is done on your build, suspension too.
10pt cage,fire suit 6pt harness for the drag strip plus an nhra comp license

for the salt i have to add in a fire supression system 5lb engine, 6lb in drivers compartment, need a different drivers seat, hans device. i will run the 130mph class the first day, 150mph class the next day, then whatever liscencing passes i need to make before i run 200+. this will be my first time ever on the salt. even if its ur first time u can run the 150mph class with nothing more then a 5lb fire extinguisher and helmet with a bolt in rollbar

im keeping the front suspension stock for the salt with the exception of 1.5 inch drop springs. on the dragstrip i have some poormans 90/10 struts and drag springs.

for the salt on the rear ill have 1.5 drop springs , 3 way adjustable shocks,lcarb, adjustable lower control arms, adjustable panhard bar

the only difference is for the drag strip ill be using the stock springs instead of the drop springs


when i do the 4l80 trans swap ill be doing a short tq arm setup with the mount moved to the crossmember instead of the trans tailshaft
 
#22 ·
Ya I agree on the crossmember than stock on the trans case, they take to much abuse there, had to modify mine on my 2000Ws6 trans am I had last year, to much abuse for the trans to take, also the panhard bar stock is crap too, modified it too. The 4l80 will be a nice change, buying a modified one I imagine, what brand. That's where your stall will come in I see.
 
#24 ·
I am looking at a TCi Street fighter #371000p1 700r4 trans kit with 2,400 stall convertor for my neighbours 72 Gm 2wd truck that was a 3spd std trans and all it needs according to TCi (it is included) is lockup kit for 4th gear. Seems like a good buy for $2,400, includes fully manual trans for 400hp up,cooler/synth.oil/dip stick and only putting it behind a 400small block at approx 420hp. Know anything about these trans.
 
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