Technical 283 SBC Question

I tore down this motor to repair leaks and front accessory mounts. I was told that the motor was rebuilt - hence all the leaks. So, i'm down to the timing cover off and intake and valve covers as well. Can I get away with installing a Comp cam 260 H (mild) w/ a Performer Intake and a 600 CFM carb? This motor does have the PP heads, I believe 64/65 Chevy II. I need to check the rear diff later for what gears are being ran. Its a 49 Chevy 3100 - little it of a dog with the 2 banger on it. It does have HEI - which I plan to swap out with a better one.

Also, can I run the stock valve springs?

Thanks in advance.
Luke

 

Valve springs are cheap get the recommended set to go with the cam.

 

Yes. All parts are compatible. To know for sure the valve springs being fresh would be reassuring, the lift is mild on the new cam. Be sure to research your oil having enough zinc to keep the cam alive.

 

Thank you very much. I will order up matching springs. Any recommendations on oil- or should I just run an additive. Again - thanks.

 

Just this week at work I read the latest reports on zinc in motor oil. Basically it said that you can run a zinc additive during break in, but the replacement additives for zinc are so good that you really don't need it. I'm sure this reply will cause a shitstorm. Personally, I've run an additive for break in and conventional oil from then on with no problems.

 

Thanks BigDog. Yes, you may have opened up conversation. LOL. I have used Richard Clarks ZDDPlus in my Turbo V6 - He did a bunch of testing in this area and people are still battling. As humans we need zinc as well - seems we don't get enough of it.

 

good advice here!!

 

Make sure your 283 has a cast in oil filter, why I say this is the 1955 engines had a cam that needed a groove in it . If yours has a filter it will be 56 or newer. I would buy a reground 327 300 h.p. if it were me, a lot cheaper. 600 is plenty carb ,should work good. There is nothing wrong with the stock distributor with a Petronix module instead of the points. Best of luck.

 

Thank you Joe Cool! Are you saying a re ground 327 crank? This motor is still in the truck - I'm going to throw some parts in this motor for the season- then pull it.

 

They didn't make a 283 in 1955 -'56. That would be the 265.

 

I have basically the same combo in our 49 3100. A .030 over 283 PP heads with 305 intake valves, hardened seats, a mild cam, new stock springs, stock dist with Pertronix, Weiand dual plane, 1850 Holley. I used a Th350 trans and a later 6 cyl rear with 3:46 gears. Been driving this as my daily since late 90's, few problems. I did have a lobe/lifter go flat several years back, always used additive, so who knows.

 

Thanks gents. So I went and pulled the oil pan. There is some metal in the pan. What is a respectable amount? The motor allegedly was rebuilt. Truck ran well and did not knock or tap. Again this motor is in the truck so I'm limited at the moment. No room in the garage. This all started because it needed a rack. Lol

 

must stop looking at avatar...hmm avatar...

 

Yeah- I had the same problem for a few hours.

 

Ah Larry, lets hope he plans to get rid of the street machine paint job for a more traditional paint job in the future. Lcats, One thing the guys didn't mention that we ran into a lot on cam swaps on 265 and 283 engines in the early 60's when my friends were doing them was make sure that the pistions were notched for the higher lift cams. The two barrel engines often came with flat top pistons and when you swapped cams the valves hit the piston. If they have the notches in the top (look like eyebrows) you are good.

In post 8 Joecool was referring to a 300hp 327 cam I'd have to think. An 80 something factory Z28 hydraulic cam brings those engines to life too but I don't what exact Z28 cam we had in my son's truck with a 307, powerpack heads, 300 hp 327 intake and Holley carb. It ran strong for what it was though.

 

By the way, the 300hp/327 cam should be the great old -929 hy-cam, the .390"/.410" lift jobber that was used in about all the regular engines back then. I know my 295hp/350SS engine had one in it stock..

Springs!!

Buy a cheap set of what I call, "Z-28" springs , they will be fine and will save you some money.

http://www.speedwaymotors.com/Speedway-Racing-Valve-Springs-125-Inch-OD-Set-16,88.html

Or....

http://www.competitionproducts.com/...18-1210/productinfo/ELGRV-943XK/#.VcY2UMscEfg

You can use your keepers and retainers with them, just watch out for "rotators" so please do your homework.

pdq67

PS., I have a set of the taller ones in my dresser drawer that I bought years ago from Midwest Motorsports.

 

So now I gotta pull the heads??? Hmm getting more involved. Notches need even on a 260 or 268 grind.

 

Thank you PDQ67! I did order up a complete matching kit from comp cams- 268 grind. Didn't really want to pull the heads - but it looks like I have to and if the Pistons are not notched...then what - used short block? I bought this truck to drive it-

 

I would like to read this article, where was it?

 

You big dummy...I was talkin about Slammed's avatar!

 

Buy beg or borrow a boroscope , that way you can look at the pistons w/o pulling the heads.
dave

 

That's what I was talking about- my avatar is just a truck pic - however Slammeded's

 

Might as well pull the heads easier to do springs on the bench. What's a few more bolts.

 

Well ,,,,,
My machinist does a set of heads with a valve job for 200 plus parts. Doesn't matter if he uses old springs or the new ones I give him unless the new ones need some work to get set up.

Then comes the cam break in procedure. It will simply say " use light weight valve springs". What that really means but is left unsaid is an entire book's worth of explanation.

Have your heads set up correctly and shimmed for correct seat and lift pressures to match new valve springs that you'll be using, done on the bench where ever the pressures can be measured, clearances checked and every other detail.

Install weak/light valve springs, install heads, adjust valves. Break in the cam. Much easier on the bench.

Change your valve springs back to the new ones that match the cam profile and that the heads were set up with. Usually done on the car, unless you pull them and do it on the bench. Air or rope stuffed into cylinder. Don't loose any parts, mix up any shims, and all that happy horse shit.

 

put in the cam and run it.. use cam lube liberally on assembly. not much lift on that cam.

 

Times two.
If it was rebuilt, surely it has 4 valve relief pistons, whether cast or forged...or if it is an original 65 283, it will have them too.

 

Valvoline VR-1 racing oil is considered "off road", still has 1200 ppm of ZDDP. NAPA has it, around $5 a quart. ONLY oil I'll use in my FI 283, with solid-lifter 097 Duntov cam. I don't give a shit what 'they' say about today's oils, UNLESS the engine has been running with street oil for the past 10-15 years, with no cam issues!

IMO, I would go with a reground -6929 cam with new lifters, NOT worry about the springs for now.

Good Luck, Tim

 

[QUOTE="Mr48chev,

In post 8 Joecool was referring to a 300hp 327 cam I'd have to think. An 80 something factory Z28 hydraulic cam brings those engines to life too but I don't what exact Z28 cam we had in my son's truck with a 307, powerpack heads, 300 hp 327 intake and Holley carb. It ran strong for what it was though.[/QUOTE]


Thanks, I was talking about the cam ,I was babysitting and can't handle the stress anymore ,,Thanks

 

So the original 65-67 Chevy II 283 (if the re-builder used stock pistons) will have relief pistons?

 

Yes, 65-67 Chevy II 283 stock pistons have four reliefs.