Chevy Tri Five Forum banner
61 - 80 of 82 Posts
I see all these comments about people taking their engine to a machine shop and having them build the engine. Does no one build their own engines any more???
I would have machine shop work done. Milling, head work, decking, valves and angles cut.
The assembly and homework to get what my goal was is too much fun. A better education would be hard to find.
 
One of my favorite 327's I owned was the L79 that was in my 1966 Chevy II Super Sport. It came with a 327/300hp, but 3 months after buying it, I went to the local Chevrolet dealer & placed my order for a L79 crate engine, & that turned that little SS deuce into a consistent 12.9 second 1/4 mile little animal with a 411 posi 12 bolt, & just as importantly to me, since I ran it on the streets back & forth to work every day, It Was One Of The Most Reliable Engines On The Street & Strip That I Ever Owned !!
This motor did not get the credit it was due, since the solid lifter cam 365 carbureted or 375 hp fuelies got all the well deserved recognition, but all three were basically the same engine. The L79 shared the same forged 11.1:1 pistons, 585-cfm 4150 series Holley four-barrel, aluminum dual-plane intake manifold (except for the fuelie), enlarged 6-quart oil pan, high-flow air cleaner unit, and big-port camel hump cylinder heads, with 2.02/1.60 (intake/exhaust) valve heads, just as the big brother L76 engines. The difference was the hydraulic lifter cam in the L79, but it didn't require the frequent valve lash adjustment of its more potent L76 big brothers with their solid lifter cams. The L79 actually had 10 lb-ft more torque than the L76, even with the 15 hp less then the carbureted L76.
If I remember correctly the L79's cam lift was around 0.450/0.450. You should be able to find all those L79 specs on the internet somewhere, or your engine guy may have them too. I know I have them out there in my shop, somewhere in the cobweb section.
I'm assuming you're not going to run high compression 11.1:1 pistons, so if you go with 10.0:1 pistons you can run 91 octane pump gas, & If you build it to the rest of the L79 specs with it's hydraulic lifter cam, you may hit that area of around 300 hp you're looking for, plus with running a hydraulic lifter cam, you can enjoy Air Conditioning in the summer. AC & solid lifter cams don't do well together, at least that's why GM never offered AC in any of their factory solid lifter cam engine cars, whether it was a small block or big block.
I'm curious to find out what your new engine find is. If those camel hump cylinder heads were factory installed, it could be an old factory L76 or L79 327 ??
Best of luck with your new project !!
 
So that you don't feel you are alone in your situation have the same basic setup but with a 350 block. You have the same heads that I have and face the same dilema but one thing that I want to point out is that the heads do not have the mounting bosses for A/C or Alternator mounting accessories. I am going to replace mine with AFR Enforcer "As Cast" heads which are essentially 2.02 / 1.60" valve heads without the CNC machining but at an affordable price point. Check them out, I think they would be a great choice. I am running a Comp Cams High Energy 268H cam and Sharp Roller Rockers which is another reason to going to the heads because they have pushrod guide plates. The sad part is the heads (the cast iron ones) have never been run since they were rebuilt 25 years ago and have been on the block for years. The AFR heads are ready to run and dollar for dollar are probably right there with having seats, valves, screw-in studs in your cast iron heads. Hopefully someone can still use the heads for something. My "Someday" project is moving up in the Que. 1955 Sedan Delivery that I've owned for 53 years and is my first car.
 
Depends on which heads, whether the chambers are designed to flow better with the larger valves, and if you go to a bigger cam to make use of the larger valves, and better flow. Just changing to larger valves can actually hurt the performance on some old camel hump heads because it moves the flow characteristics out closer to the edge of the chamber, and creates poor flow issues if not unshrouded.
On some of the later high volume heads with larger runners, and the larger more open combustion chambers, the increase will work well, and make good gains. But it's just not the same on the small chamber camel hump heads. Compared to many later heads the camel humps are a poor performance choice.
Agree!! If you are looking at putting money into double hump heads with all of the mods mentioned, I think you are much better with an aftermarket aluminum, Trick Flow maybe. There are cheaper aluminum heads with specs similar to the Trick Flow, but are they quality heads, or cheapo knockoffs? I would go with a 9:5 Vortec. Tons of them out there, much cheaper than redoing double humps, and most will outflow a double hump. Keep it simple is my mantra.
 
I built my 350 specifically to be a good driver first, with mild performance, but the ability to run on regular gas if I want to. So my first priority was not a high compression engine, and not a big lopey race cam. I do have an Edelbrock Performer RPM intake, 650 cfm Quick Fuel carb, and stainless headers. But I used the SBC 487x heads because they have a large combustion chamber that flows extremely well, and wouldn't raise compression. These heads also have runners that flow as good as many aluminum aftermarket heads, which I wanted also.
I went with a Howards roller cam because my engine is a 1990 roller motor, and I wanted a roller cam anyway. I'd guess it might be making 325 h or so? But it fires at the touch of the key, hot or cold, and runs 175 degrees on the hottest days. And with the 700r4 OD trans it gets over 20 mpg on the highway in my '39 Chev coupe. So it's exactly what I hoped it would be when I assembled it.
 
That wide 114 LSA and short duration should have no lope at all.
Those are the same specs as the L79 cam. The reason it lopes is that the "advertised" duration is huge, even though .050" duration is relatively small. It's also the reason that those engines had pop up pistons and 11:1 compression ratio. You can and should run a bunch of compression with this cam because it lowers dynamic compression ratio so much.

BTW if this was a typical modern aftermarket cam with those specs it wouldn't lope much. The modern cam's "advertised duration" would be 40-50° less.
 
Personally, I don't think the '151 cam shaft is the right one for you Larry...That cam was meant for high compression, engines with taller gears (correction shorter) in the rear to keep the RPM's up...Also, IMHO, it is better suited for a standard shift transmission and surely not an auto OD with 3.42 gears...The operating range for that camshaft is from 1,800-5,800 RPM...Your engine will only be operating at the very lower end of that spectrum...Just my two cents,
 
engines with taller gears in the rear to keep the RPM's up..
A clarification on on the lingo. "Taller" gears are lower numerically and keep the rpms down. "Shorter" gears are higher numerically and keep the rpms up. Shorter in that you run through the rpm range sooner with respect to speed.

Agree that the 151 cam is not what the OP needs for his stated goals. Many here are trying to spec the engine they want instead of what the OP stated he wants.
 
A clarification on on the lingo. "Taller" gears are lower numerically and keep the rpms down. "Shorter" gears are higher numerically and keep the rpms up. Shorter in that you run through the rpm range sooner with respect to speed.
Thanks for correcting my Faux pas Rick
 
My comments on the 151 cam were only if that cam was used by anyone not just the OP he should build the engine expressly for his intended use I have used in nearly stock 327-350 engine one made by Elgin if memory serves me it was around 112-118 on a 112 LSA makes a little lope drives perfect with a stock converter I also used a Lunati with nearly same spec that's works nicely in a stock type build good luck with his build
 
61 - 80 of 82 Posts