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Cam suggestions?

Bugflipper

Bugflipper

New Member
Well I ended up with another t-bucket. It's going to be a slower build because I've got to go through it and re-weld everything a PO did. Over the weekend I rebuilt the bottom end of the 70's 350 truck engine.
I plan on driving it a good bit on the interstate but still want some spirited straight line romping. I'd like to just stay with the stock converter. Comp cams hasn't gotten back with me yet. Lunati reccomended a 268 voodoo. Wanted your fellows take on what you think would be a good one. Here's the rundown.
Stock hei.
64cc aluminum heads 190cc int runners.
Stock crank and pistons 9.3 cr.
T-bucket 1.75" headers into 3" gp header mufflers.
Weiand 7546 high rise 1500-6000.
Street demon 625 carb.
700r4 and 3.42 rear.
Thanks
 
The only thing I raise a question to is the 3.42 rear with that 700 trans. The 700 has a OD ratio of .7 , with that rear gear that equates to a final drive of 2.39. That is pretty high, and even with a light T bucket it might not be low enough. Tire size will enter into this as well.

Try this calculator to see if it all works for you. http://www.wallaceracing.com/calcmph.php
 
I've ran the voodoo cams they don't make the power thy are suppose to. I would wait on comp and have them make you one. I would think a comp 280 would be a good choice tho if you don't want a roller.

And I agree with Ron I would run at least a 3.73 if you want the down low power.
 
I agree with Ron....depends on your rear tires, since your going mild on the motor. I really like Lunati, the VooDoo as you were told are pretty mild. Good cam, if your going mild with a dual plane and a sm. carb. Another good one is The 268 High Energy....and if you want a good basic jump in horses and want the hotrod idle, go with a Thumpr Cam. The Thumpr's are fairly mild, they just mess with the overlap, etc., to get that sound.
The main thing is to match your parts, which is already done. A well matched motor will often time smoke a hotter 'built' motor on the streets if its in tune.
Remember, if performance is your thing, degree the cam in, make sure your cam walk isn't excessive, you can pick up 3 to 5 horses there. Also, you can play with a carb spacer and pick up a few horses there too.

If, If your good at tuning, you can get a older single plane intake, you will loose just a touch of torque at low rpms....but what you would loose just off idle, you'd more than pick up in midrange. But that is only if you really like to fiddle with things.
If you want to just cruise and go....stick with the dual plane intakes.
 
The first thing that I questioned was also the rear end. My gear choice with a 700R4 is always something that starts with a 4. A 4.11 rear end with a .7 overdrive is only a 2.88 final drive. The final drive in my T-buckets is 3.89 (350 trans) and it works fine, given that I pretty much stay under 70 mph. To get a final drive of 3.89 with a 700R4 I would have to use 5.68 rear end gears, so IMO, anything in the 4's wouldn't hurt.
 
+1 on higher number gears.

I have a 700R4 and 3.42 gears in mine. My cam is a Ramjet 350 crate motor roller. Probably similar to or maybe even a little hotter than the 268 cam's you listed. The 3.42's work good at 70+ MPH, but tend to really lug the engine below 60. Around town I use 3rd gear. No overdrive unless I'm on the hiway.

My future plans call for going to 4.11's.

On the other hand, at 50 MPH with the converter locked, it does make a loping sound like a few Harley's running together!:cool:

Mike
 
I do have a spare th350 that could go in it. No big deal it's a high enough ratio to not have an overdrive. Wouldn't have to worry so much about it lugging at cruising speed with a midsized cam. I typed the wrong compression ratio above it's a 9.8-1. The tires are 28 tall nitto drag radials. I have read a lot of reviews on the center wearing quick at 22-24 lbs on a regular weight car. Will probably try to run 18 or so in them. Would probably put the diameter down to 26.5 or so just guessing. Thanks for the help so far guys. The main thing is I would like to get decent power out of it. Don't want to have to brake and launch, just a cruiser that will put a smile on your face when you nail it. The heads and intake should match well for 1500-6000. Was looking to maybe get over 400 lbs of torque out of it. Also hoping to get the hp up as well while being streetable. To be honest I don't know anything about roller conversions.
 
I kind of like the rear ratio. I have the same in another bucket but it has a th350. Just a stockish 327 vette motor and it's a little screamer. I think the ford rear in my 30 3 window is a 2.79 behind a th350. It is 2200 with a stockish 68 chevelle ss 350. Raced a fellow in a corvette and striped him several years ago. He wanted to know what motor and all. Said he had a twin turbo callaway and had never been beat. Not trying to brag probably every fellow here has a faster car than me. I just don't pay a whole lot of attention to low gears. He stated and I can't remember but it seems like he had near 200 hp more than I did. Let's say his car weighed 1000 lbs more? He should have still blown me away. A light car with the suspension set up right can get by with a higher gear as long as the engine has enough torque to overcome it IMHO. My 3.42s seemed a little low to be honest. :p
I like to build torque, it makes up for the high gear. The motor doesn't have to turn as high so you don't have to freshen it up as often. No experience with the 700r4 though. I think I may put that in my scout. It has 5.38 gears, may make it more friendly on the interstate.
Again thanks guys. I do appreciate the help. I really don't know much about cams. I always just pulled motors with good casting numbers from the junkyard, freshened them up and did the normal bolt ons. Now they are in short supply with the scrap prices so high.
 
On the roller cam, you will get a really good increase in performance because the opening and closing rates will be so much quicker than with a std. flat tappet. Not to mention the reduction in friction, and in a flat tappet cam, the rubbing is transfered into heat and wear, though its slight. You get a couple of hundred pounds of spring pressure transfered onto that lifter, even though they are hardened and it has lubrication, there is heat build up.
When I assemble a motor, I drop all the lifters in, I mark the top lip of the lifters with a line from a MarksALot. I turn the motors over, and make sure all the lifters rotate as they should. I find some that don't have enough radius on the lifter, so I send them off.
You can get roller like performance with a flat tappet by going to mushroom tappets. But, if you find a good used roller motor to rebuild, your well ahead of the game. Roller cams and lifters are expensive initially. So scoure the salvage yards and get a roller and rebuild it. Then there are the retro-fit kits. It all depends whats in your budget.
400 ft-lbs isn't that hard to get to. Its quite easy to get 430 -450 horses with a 350 these days. Cam, headers, a good 650 cfm carb, and a good intake will get you there. Call the cam grinder and tell the salesman what your doing, 400 ft-lbs@ 3200 to 4200rpm is obtainable.
A roller isn't needed to get these numbers, but it does make it easier.

Got to remember that chevy had a 350 horse 327, and a 350 horse 350 back in the day, stock from the chevy racing boys. They had more compression back then, and had better fuel.
9.1 to 9.5 will require premium. If your above 9.8 to 10.5, be careful of power robbing detonation....if you have a set of performance angle plug heads, detonation can't be heard as well. You'll have to mix your fuel a little. Premium with some octane booster and maybe a few other goodies.

Funny thing, that E85, when mixed, is a great anti knock compound....just do your research.
 
I am a big fan of the comp cams XE line. I am running a 262 in my bucket now, its got good low end and a mellow sound. I ran the 268 in my 327 and loved that one as well.

As for the 700r4 v th350. You can always drop the 700r4 into 3rd gear, you cannot put a th350 into 4th.....

I am running a stock "Grand National" convertor in mine, and I find it just about perfect for my style of driving. A bit more stall then the regular 700r4 convertors.
 
Keeper said:
I am a big fan of the comp cams XE line. I am running a 262 in my bucket now, its got good low end and a mellow sound. I ran the 268 in my 327 and loved that one as well.

As for the 700r4 v th350. You can always drop the 700r4 into 3rd gear, you cannot put a th350 into 4th.....

I am running a stock "Grand National" convertor in mine, and I find it just about perfect for my style of driving. A bit more stall then the regular 700r4 convertors.
Click to expand...
I thought that the Grand Nationals had 2004rs in them?
When we have used the 700 we used a converter for a 4 cyl S-10 truck. It would stall about 2500 and still lock up in 4th gear.
 
Thanks for the link SM, I bookmarked it. My heads are pretty well identical to those. Pro Comps are Chinese made and contracted through Australia then sold here. I bought a set of Racer Pro that are made in AU that pro comp bought the design from. I was looking into the pro comps but there are a lot of bad reviews on the quality of them. RP had a sell since they discontinued this smaller runner head. I have wanted a set of aluminum heads for years but couldn't justify the cost. I got these cheaper than I could have gotten a set of camel humps and had them machined so I am happy with them. I will have to look into that summit cam a little more. That matches pretty well what I wanted and fits the rpm range I was shooting for. I'm starting to get a few more recomendations in from other places, still nothing from comp. It's helping me learn a little bit about cams. I figured this would be a better place to learn since folks have already figured out what works and what doesn't from trial and error. A computer program can only go so far.
Thanks guys.
 
Well the manufacturers just muddled the water pretty much. 256-268 cams suggested. Just depends on which rep is reccomending. The same company will reccomend a 268, then the next guy says 262 then the next one 256. One fellow at crower was trying to make a thumpr style cam on a custom grind with a 350 hp projected power output. Boy oh boy, looks like I'm back to square one.
 
Hahaha....well, diff. mfg'ers won't have the same cams; the duration . lift and overlap will be slightly diff., so someone can SAY_ IS THE BEST GRIND FOR _. I think you'll like the High Energy 268, or its equivalent. Yes, the Thumpr is almost the same one, but with a bad sounding lope to it. They are basically the same thing.

The Hi Energy Series and the RV cams are close to the same thing....don't let all the psycho-babble the guys say confuse ya....some of them want to impress you and think theirs is the best.
If you gave any more trouble, call Melling....get one of theirs....they have all the std. replacement cams for all the Chevy Factory and high performance apps.
 
Joe Hamilton said:
I've ran the voodoo cams they don't make the power thy are suppose to. I would wait on comp and have them make you one. I would think a comp 280 would be a good choice tho if you don't want a roller.

And I agree with Ron I would run at least a 3.73 if you want the down low power.
Click to expand...
I have a comp cam 280 700 r 411 gears and a ford 9 inch 18.50 x 31 tires and Cruz 70 at around 2100 rpms but comp cams said I would have to run a 2500 stall converter so I am. It turns a lot of heads when idling around has a nice bump to it
 
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