Depending on the cam selection, you may need more carb than you originally planned - to make more HP on the top-end. Also, it depends on whether or not you want to run a double-pumper type setup or vacuum secondaries. I ran a 600 DP on my last 283 - ran really well! You might consider speaking with somebody at Bullet Cams about your exact package. I'd probably pin the rocker studs - no reason not to if you have it apart. Also, given that you 're putting new pistons in it, the whole rotating assembly will need to be rebalanced - or at least checked. Make sure you bring them your flywheel, clutch and harmonic balancer as well.
Losing the unnecessary 800# would shave 2 seconds off your 1/4 mile time , cheaper to go on a diet than make the little motor go fast , or put a big block in it !?
Why not build a "Fuelie" spec short block and modify a pair of Power Pac head's with larger intake valve's (1.84" or MAYBE 1.94") add in some bowl and port work, and drive the shit out of it? Granted, the Power Pac head's are not the most cost effective, but you'll have the Traditional look and performance that is so highly revered. Or... put the big head's on and top it off with a blower! JMO
I always thought the popular route to unshrouding the valves was to open up the bore of a 283 to 4.00” for a 301 (302 when Chevy did it for the Z28).
Nope, started life as a roadster till late 80s when the coupe body was mounted...I got it 7 years ago from my best friend who had it in the 80s from Grand island nebraska
I milled that idea over but since I had these forged pistons, balanced crank, rods and block...going this way
Did these forged pistons come with the crank and rods you have - all balanced as an assembly? Cranks are balanced based on the bob-weight of the other components. If your crank was balanced with other components - it is important to know that when you change components it is no longer balanced. Sounds like it should be a fun engine!
It was a complete short block that I got with the coupe 7 years ago. The machinist looked over the crankshaft, said he can turn it, recondition the rods, tap it for a balancer bolt and hone the back for a roller bearing input shaft (running a t5). It had 1.94 double bump heads on it and an l79 camshaft. Last owner said he hit 7k a lot...I am going to run that set up again but with a larger capacity oil pan. Thanks for the advice
Just a quick trip through a compression ratio calculator shows that 9.7:1 comp with 64cc head drops to 8.2:1 comp with a 76cc head. Your 283 won't like that at all.
I hear a lot of talk about cams and heads, I have built a few 283 and I have ran 461 heads and 416 head with 30 over flat tops and 3 duces set up old holy 94 MSD dizzy and it runs great. what i am not hearing is what trans you running, a 3 or 4 speed auto 3 speed 4 or 5 manual? I have called different cam manufactures and told them what I am building and they will help with your cam. But the older guys I have know and hang with all tell me the coast to run 202 intake valve is not worth the grain. Good luck with your build and long live the 283 love them.
I am running a modified T5 camaro world class five speed manual with an s10 tail housing to put the shifter in a better location along with a 3.70 rear axle ratio in a ford 9 inch and a 25 inch tall tire. I appreciate the insight about the return on 2.02 valves
I ran an L79 hydraulic cam in my 62 ChevyII custom 100 coupe with a relatively stock 283. It originally came with 4 cylinder and was the lightest model. The rocker press in studs were pinned with set screws. I had a wide ratio Muncie and 3.08’s as a daily drive to work and 4.56’s on the weekend. I put it together in 1965 It was a great runner and could handle a lot of higher hp cars because it was pretty light. It’s one I wish I had back.
I have read through this entire post seeing all the recommendations and think I have picked up on the direction you're thinking right now. Something equivalent to an l79 cam with the double bump 64cc heads if I'm reading your posts correctly? In my opinion would be a good combination. If the l79 specs I found are correct at about .450 lift it doesn't seem to me you need a valve spring with enough pressure to justify screw in studs and guide plates unless you just want that feature for bragging rights. The 64cc heads will still make good compression with a 283 as long as the Pistons used have a compression height that brings the Piston tops close to the top of the bore. One last thing to consider would be finding the thinnest head and gasket thickness as possible. The last engine I built was a 305 and I actually ended up re-using the original steel shim head gasket with a good coat of copper gasket spray. It's worked out so far quite nicely in the front engine dragster I built. About all of the head gaskets I've found that are made today, unless you go to some expensive custom-made head gaskets, are sized for a 4.060" bore which loses a tiny amount of compression as well as leaving a thin, narrow gap between the head and block before you reach the diameter of the head gasket. Personally, I didn't think that was a good thing to have. In short I think the l79 cam and the 64cc double hump heads you have would be a good combination. I'm not an engine builder so take that with a grain of salt. Good luck with whatever you decide to do. By the way, what town in Missouri do you refer to as Central Missouri? I am in Uniontown Missouri which is about halfway between Perryville and Cape Girardeau. Lynn
Thanks, I will look into steel shim head gaskets and the modern version of the L79. I am outside Camdenton Mo. I appreciate your input
Ah....Candenton. years ago my wife and I had two different places at sunrise Beach mostly for weekend use and eventually lived at Lake Ozark on Horseshoe Bend for a short time. After all of that, oddly we've hardly been back to the lake at all in over 15 years. Lynn
The thing you need to consider before doing anything is how well the engine drives or accelerates with its current parts. People get enamored with "it makes THIS much HP" but forget about mid -range torque. If you get a new cam, and build for peak rpm HP, you will most likely have poor mid-range driveability. A 283 is not a torque monster to begin with, even tho its in a lightweight car. Don't make the same mistake many many many people have made and over cam the engine. Think about it this way. If you took a reading of the HP being made every 1/10 of a second while accelerating in a quarter mile. The engine that makes the most average HP all thru the driving range will perform the best. One that lacks power at the lower rpm and suddenly peaks when at 5000+ rpm will not perform as well....but you can always brag about the HP you make but not your ET. I'd think about selling it to someone who is building a 57 Chevy or needs a 283 and invest that money in a 350. Thats why you see so many 350s in old hot rods.
Back in the late 60's I ran a 283 in my '55 Chev gasser. It got 1.94 camel hump heads, with 64cc chambers, and the old solid lifter Duntov 30-30 camshaft. The guy who did most of my build was a very good engine guy, and did a lot of porting work to the heads before they went together, plus converted the heads to screw in studs and better springs. Not that the 30-30 cam was extremely high lift, but it was going to see high rpm shifts at the drags. These days I'd probably not do a flat tappet camshaft as they'r just too sketchy and questionable reliability now. So if I spent a bunch of money I'd also spring for a roller camshaft and lifters, but still go solids. Pistons were a set of Jahns forged with a small dome, and I was told the engine would be around 11.5:1 CR. I ran a Corvette dual quad intake at first with twin Carter AFB's, but quickly found they didn't perform that well. I changed to a Weiand single 4 brl. intake with a 750 Holley and the engine really came to life.
Around 1979 we did a very similar HS Auto shop build for a 28s in a 67 Camero it had 12-1 .060 over TRW pistons the Duntov 30-30 cam and Offy 2x4 tunnel ram with twin 660's . We had 461 heads and they were ported by myself after reading Hot rod and how t build a small block chevy LOL and some crane roller rockers aluminum retainers and 194 swirl polished valves and a cheap stud support Z28 springs . that little engine screamed . It Was a high school legend I saw it go 12.98 at Sears point on a 10" slick that was fast then for a car with every thing in it and ran on the street and drove to the track with slicks in the back seat . MY buddy still has it with a BBC in it now. I always wondered how it would have went with a 4.56 gear, better cam and professional porting and more tire . That thing took down a lot of BBC a cars in the year it ran that engine before it lost piston to a Nitrous kit attempt and a fuel solenoid not coming on . Point is a lot of 283's ran good with the old camel hump heads / 461's with 194 valves and a cheap over the counter GM cam and springs . Good gas and compression would help a lot today .
If I read right you're trying to use heads on hand because you have them. That can be a black hole sometimes. Says you're in central Missouri. Which means you're in the same marketplace range as I am. I know local-ish to me 305 ho heads can be had any day of the week for $50-100. Usually ready to run. And they already have ports to go with the 1.84 valves. And already ready for unleaded gas. And similar enough in chamber size there's no compression juggling. And likely even result in better mpg. So while you may be trying to run what you have to keep costs down you may actually be costing yourself more $. I've fallen into that trap many times myself
Ask Away! with Jeff Smith: Best Performance Upgrades for a 283 Chevy Small Block Engine - OnAllCylinders A decent article on what you will have compression wise with 461's and all that . A small dome piston would be nice
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