Technical Your opinion on a camshaft

I was agonizing over cam choice for a recent BBC build, with a very specific use case (tow rig). My problem was there was no way to know for sure what the hp, tq, vacuum at idle, etc would be with my different cam choices and this head/intake combo. Luckily I stumbled on to a cam designer who's been doing this for 20+yrs, he designed a customer roller (we're having Comp build it) for exactly what I need. Let me know if you'd like his contact info. He's remarkably affordable if you order the cam through him, he charges less than a steak dinner. The software he uses is pretty impressive.

 

https://www.claysmithcams.com/h-290-8-b-small-block-chevrolet-hydraulic-flat-tappet-camshaft/

 

I ran the 30/30 in a 283 I had in my '55 Chev 150 gasser in 1970. Basically the same 4 speed, and 4.10 rear gear setup, but with dual AFB's on a Chevy intake manifold. My heads were the smaller 1.94/1.60 camel hump heads, so a little larger than you have. It ran extremely well with this setup for street and drags. But I later changed to a single 4 barrel intake, and a big quadrajet a buddy gave me off his 401 Buick engine. The big quadrajet really woke the engine up, and it picked up a half second in my 1/4 mile times.
Loved that little 283 and at the drags I shifted it at 7,000 rpms. Was a screamer that turned in the high 12's which I thought was pretty fast back then.

 

If it is normally street driven and you have kept your compression below 10:1 what you really want is something with a 112 lobe center and around 450 lift. If your compression is above 10:1 and you want to drive it look for something in the neighborhood of 108-110 lobe centers. I like a lot of duration but most guys don't.

I normally suggest an L79 cam profile for a street motor. But a lot of old school guys are going to suggest the Duntov 30/30 for the short stroke motor. Depends on if you want mechanical or hydraulic.

I have looked at the comp cams camshaft in the classifieds myself. it looks like a good cam to me. I would not be afraid of it. I am personally looking for something specific or you would not be looking at it. LOL

 

So what is a good current source for an 097 cam these days. It sounds like Speed Pro and Elgin don't offer them any longer? I have a little rebuilt 283 that I'd like to add a little rump and lifter noise to also. They go in straight up or advanced/retarded a little?

 

You may check Lunati. They probably are not making a blueprint but they probably have a cam with the same basic profile and they make a damned good camshaft. my experience is that they are good to get back with you when you drop hem a note. Send them the specs and they will probably get back with what they have to offer that will fit your desires.

 

I always forget about Lunati. They got sold to some big conglomerate but he bought it back didn't he? So they are still good?

 

The "pro advice" stuff is what I like about Delta Cams. They still talk on the phone the last I heard! I've talked to one of the guys that runs the machine!!
They 'know' what a Duntov 30-30 is........or Comp 292.....Ken is NOT a sales-geek, he's a grinder.
6sally6

 

With those early, small port and valve heads, I wouldn't try for high rpm horsepower at the expense of low end torque and mid range horsepower, cause the high rpm power isn't gonna happen without making a dog outta it on the low end. The 097 would my absolute maximum if it were mine.

 

DOM.........don't forget he's running a 4 speed AND 4.10:1 gear. That combo should handle a pretty radical/snotty-cammed set up! Seems the heads might be the limiting factor. Trips to 7000 rpm would be very do-ble (if other stuff is up to it)
6sally6

 

Seriously considering some 305 heads. Machine shop has a set with 1.94 valves. Guess i can put the power pack heads on the shelf for something else

 

I put am L79 in a power pac 57 283 with a stock intake and an adapter for a C series AFB. It ran great. Make sure you use screw in rocker studs. Trust me.

 

305 HO heads, (58cc) are a good option on 283's. Look for casting number 14014416.

***1.94 valves are upgrade for 305 heads, not stock.

 

^^^^^ aren't 416 305 heads 1.84 stock?

 

L69 is 305 HO, came 14014416 and 14022601 heads, 416's are most common. 416 and 601's could have either valve size (80's GM was a mixed bag, verify everything) 58cc chamber is the strength of these heads. Smaller port size and decent chamber for a factory head works well on a 283 for driver / light performance.

Used a set of 416's (1.94) on a 307 rering budget build, picked up compression from the 58cc chamber, L82 (.450/.460 222/222) factory take out cam a friend had laying around. Surprisingly strong little combo with great manners, good vacuum.

 

Mixed bag of valves yes. But where are the 1.94 intake valves?

Details for 14014416
Manufacturer Chevrolet
Category Cylinder Heads
Type Small Block V8
Date 1980-1986
Notes 305, 1.84/1.5 valves, 58cc chambers
Added to DB 2010-12-20 22:55:48 (3764 days ago)

Details for 14022601
Manufacturer Chevrolet
Category Cylinder Heads
Type Small Block V8
Date 1980-1986
Notes 267 or 305, 1.72/1.5 or 1.84/1.5 valves, 53cc chambers
Added to DB 2010-12-20 22:55:48 (3764 days ago)

 

HEY! you guys gonna fight, i want a front row seat to that shit! No intentional nut shots, everything else is permitted, protect yourself at all times! ding ding!!

 

Arguing about 305 parts is about as bottom of the barrel as it gets for entertainment. Johnny Gee has the info 1.84 stock, 1.94 is machine shop upgrade.

Lloyd, hope the build goes well. If the 305 heads do have 1.94's, and are very cheap, its not a bad route. Big RPM look for a head with more port.

 

Lmao!! Ain't that the truth my brother! I love you guys the way he talked, he'll trade with me. I believe they were on some bored out dirt track car to bump compression. He did some work on them but the guy never came back to get them, so when that happens, he sells the stuff to get his money. He's a good guy, i painted his 55 Chevy a couple of years ago and became good friends with him. So we kinda help each other out.

 

True 097 cams are pretty puny lift compared to almost any modern cam, and wont work nearly as well as most cams built today. With under .400" lift they'd not be my choice.
This Howards cam is a nice flat tappet camshaft that would work well with a stick, or a little higher stall converter automatic.
https://www.jegs.com/i/Darrell+Russ...Ae4BBnkzPu-dmgS1dom_tD6oO_gjHAIAaAk5jEALw_wcB

 

So which is more important to cylinder pressure and the amount of air and fuel being pulled into the cylinder, lift or duration? I've always heard guys argue about this, but to me, (and keep in mind, I'm a painter that builds his own engines, not an engine builder) an valve that stays open longer and closes quicker is better.

 

I think flow is affected by both. But not enough lift can restrict the flow, and not fill the cylinders as well. I like cams for the street under 300 degrees duration, but lift depends on the use. A short duration high lift cam can really help an engine breathe well as the valves opening further can unshroud them better on a SBC combustion chamber.. And not cause as much raw fuel to be left in the cylinder as the longer duration cams. Too much duration results in unburned gas going out the tail pipe as at some point it's just tough to clean out the cylinders with long duration cams. Most SBC small combustion chamber heads have valve shrouding issues anyway. Only the larger chambers effectively unshroud the valves, but then you end up with larger chambers, and lower compression.
I try to go around .480" to as much as .530" lift, but really .480"-.500" is great. Another cause for rich running engines is the very short LSA that some cam makers use to get a lopey sound. If the rest of the cam isn't up to it, or the rest of the engine isn't well built, it ends up like a Thumpr camshaft with a cool sound, but lack of performance. For a SBC I prefer a LSA of no less than 108, and 109-110 better. Unless it's an all out drag race build that needs shorter LSA.

 

That's was why I used the word "stock" when I questioned.

Sorry Lloyd

 

My go to cam has always been the comp 280 magnum, 230 @ .050, .480 lift, 110 lsa. But what I'm learning is the 283 doesn't respond well to a "big cam"? And I've fell into that thumpr hypnosis, then i was told they are a parking lot cam, sounds good, but doesn't make the power to match.

 

Don't you be sorry my buddy

 

It's just that I've used several 416 heads in the past and still have a set in the garage.

 

I had one set on a 350 that somebody else put together, but that's it.

 

Seein' that you don't have the pistons yet, why don't you shit can the flat top's and get the fuelie domed pistons? Then you'd basically have a 270 HP longblock with the PowerPak heads and the Duntov cam, and those things ran pretty damned good. Just thinkin' out loud...

 

I'm curious how you had the block machined and you don't even have pistons yet.

 

I still run 'em. Not in everything (I am running a crane from the '90s in my 355) but if I am building an engine from scratch and don't have a cam shaft they are always a consideration. I don't have the number handy (I could walk to the garage and get it) but they make an RV cam that I really like for a moderate street 265/283. I have used it in a few and it works really well.

I really like their throttle stop cams for bigger motors. They were designed for bracket racers back in the '90s and were made to go from full throttle to zero throttle and back again in an instant. They really work great on a car you drive in city traffic.