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What started as a little preventative maintenance replacing gaskets and seals, just turned into surgery. The car is new to me and the thought was to have it as a project for the kids and I. I was not looking to pull the motor until next year as we have only put about 200 miles on it before winter. I do not have the money budgeted to do motor work until next winter but I would like to still drive the car this summer with the kids. I want to keep things pretty tame until the motor comes out, who knows what the plan will be then. Everything is stock with the crappy 264 heads with the exception true dual exhaust which needs to be installed. All the smog stuff is pulled off but the computer is still being used. I would like to keep it that way for now.
I pulled the intake to replace gaskets and then the heads came off to replace gaskets while I was in there. I was getting ready to start putting things back together but I just had to take a look at a lifter, which turned into looking at all the lifters. My lifters are bad which I am assuming made my cam lobes are worn down. I have to replace the lifters and I better plan on pulling the cam.
With everything basically stock, what cam options do I have that can be used with all the stock equipment? Keep flat tappet or replace with rollers that can be reused on a future build? I just want to be able to drive the car this summer and enjoy. Next winter I will get rid of the heads, intake pistons..who knows.
Thanks in advance and I did try to search but nothing fits my situation very well.
an RV cam ... xe262 or voodoo 262 cam and lifters kit is a decent economical upgrade. if the car is stock, to make it peppy on the street you want low end torque not high rpm hp unless you think you may find yourself reving to 5000+ rpm? (This is why car and driver magazine reported the L48 vettes were peppier and more fun to drive on the street when they test drove them new) L82 cams give up some of that low end power on takeoff for higher power at higher speeds.
If you put flat top pistons and better heads then the 262 cam will still be a good choice with the stock gearing. a larger cam might make it seem like a dog on the street since the power band wont kick in until your already up there in rpms.
I was in your position and found it easier to buy a fresh 4 bolt block and tear it down and start from there. The original engine sits on a stand in my garage. It also had a couple bad lifters /cam, I assume from the previous owner not using a ZDDP additive. all that metal likely didnt do the rest of the engine any favors...
You could find a great starting point or possibly mostly complete better long/shortblock on craigslist or facebook from someone else upgrading to a big block or 383, 406....
for the time being and until Next Winter's larger project
if you have Not already re-installed heads, use thin steel shim gaskets to raise compression slightly and to improve quench height. Fel-pro 7733SH1 are good choice and they're packed Each; so order Two. about $14 each https://www.summitracing.com/parts/fel-7733sh1
Summit's cam & lifter KIT is a hydraulic flat tappet cam much like like your OE L81 cam; But it has about 0.035" more lift and about 10 degrees more duration. It's a mild RV-type cam that should work with your L81 valve springs and mild enough to be computer-compatible. About $154 for the kit including both cam & lifters. https://www.summitracing.com/parts/sum-k1102
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For after y'all have driven it a while and are beginning planning stage for more performance
I suggest another motor in toto. Begin with acquiring a core / rebuildable GM rpo L31 iron head Vortec 350/5.7L sbc found in '96-'02 GM lite-mid trucks with "R" as eight character in VIN.
L31 is the latest and greatest of iron-head sbc and have many desirable improvements. Its one-piece rear main seal is far less prone to leaking than your L81's 2 piece rms. L31 already has a roller cam & roller lifters and those lifters can often be simply cleaned and reused and a new roller cam can be had for about $280. L31 has those good-flowing & sturdy Vortec heads; which makes for combined great efficiency & power. Build up an L31 over Next Winter
Perhaps ditch the carb for an EFI conversion such as Holley Sniper etc.
is the engine still in the car? you are about 11 bolts from having it upside down on the stand. replacing rod bearings is doable but no fun reaching up from underneath. you can find a 200 buck cherry picker on f-book or craigs for 100. stand for 25 to 50. and re-sell the picker for the same 100 if it is in the way. pull the crank and clean polish it. read the bearings. post pics of what they say. are they GM bearings with a date a minth to a year older than your build date? or FM or SP or King, etc and std or .001 or higher? but at this point a backyard a$$hole rings-bearings job i think would be worth considering over tryna replace bearings over your head. and cams are way easier to install when cam hole is pointing straight up.
Kind of funny how gaskets and seals turned into pulling the motor but I agree. After removing the the rod bearings the crank was clean. I just pulled the rear main to replace the seals and have a picture of that bearing. This was a couple days ago. Thanks for the honest advice. This forum is great.
it is not a car you have to go to work in tomorrow. pulling the engine gets you a lot of "while I am in there" stuff that is not real spendy. and engine compartment will be much prettier with a bath and some paint. research the correct or accepted colors to use on what part. there are many who feel flat tappet cams no longer have an excuse for living. but 100 buck ebay roller lifters are worse.
Stand by, I may not be able to answer the goals and budget yet. I have only put 200 miles on the car so far. My brother in law may have some better heads for me but I won't know until next week.
In general I wanted a fun car to drive with the kids on the street. If I keep the same motor, I would think my limitations would be the 2 bolt main. This could be a good thing since it will keep me from going wild on the build. I am open to dumping the computer and upgrading distributor, intake, cam and carb. I will be pulling the motor so new pistons and bearings make sense.
P.S. when I went to pull the heads, one of the long head bolts was out about 1/4" but it was tight. Someone got lazy I guess and when the torque wrench clicked, they stopped. They didnt notice the bolt was not bottomed out on the head. This should have been a sign of things to come.
There was a bunch of crap in the threads and in the bottom. I am positive you are correct.
The motor was born in the car but I am open to change.
Pardon my ignorance, what is an RMS crank? I think i have a lot of access to SBC parts if i know what to ask for. I want to keep it drivable on the street with pump gas. Convincing the wife is another project in itself. I'll work on that and always plead ignorance.
this rms not audio power output.
here, RMS = rear main seal ... all sbc cranks have some sort of rms
originally 2-piece rms ... by '87 the changeover was complete to improved One-piece rms.
Both blocks and cranks changed and are not interchangeable. But rods didn't change.
02-05-2022, 12:12 PM
Stock 81 L48 looking for cam advise
