I have an 80 with an L-82 and 101k miles. Everything is stock right now and I'm wanting to spruce up the engine a little this Spring. In my research I have found there are several ways to do this. I'm thinking of Intake, Cam, Lifters, and timing chain to start with. Something like this: http://www.holley.com/300-502.asp

I am very new to the Vette world so I'm wondering if making these changes will only lead to more problems down the road since the motor already has 101k. Could doing this add more stress to the engine?

I'm also considering a new carb. Which would make more sense to complete first?

 

i would be concerned with doing a top end build and ignoring the bottom end. There are at least two things to consider: your goal as far as HP and your budget.

You might want to consider a crate engine.

 

I never really considered a goal for HP. I guess I just want to give it a little extra juice and improve performance. What are some mods I should consider to improve the bottom end?

I think a crate engine will be a little on the expensive side right now.

 

i am not an expert but i would start by looking at the condition of the bearings. the last thing you want is to end up with a rod sticking out of the block. Also check the condition of the crank (wear) , connecting rods, and pistons.
I hope this helps

 

Before you do anything, check your cold/hot oil temperature on a moderate to warm day, not on a 19 degree day. If your oil pressure is within spec's, move to the next step. A simple compression test, especially how much the psi goes up in the first compression stroke is a good indicator. Since your not replacing the heads, a leakdown test would be better. A leakdown test will tell you more than a compression test but, the tester is a bit more money, hopefully you could borrow one. If the oil pressure is good and the cylinders are tight, I probably would take a chance on just a cam/intake combo. Is it a roller cam? If you have to pull the heads, personally I would do the bottom end also.
Carburetors are a very popular topic, you didn't say what was on the engine now.

 

Unfortunately I don't know how to do any of that. I wish I had those skills but anything engine related that needs to be done will have to be taken somewhere. I am able to install electronics such as speakers, subs, amp, and CD player- all of which I'm doing now.

The kit I was looking at is this one: http://www.holley.com/300-502.asp

I don't know enough about this to know what you mean when you say "do the bottom end". Is there a kit for that?

Everything engine related is stock right now, which includes the carb.

 

Holley makes a good product, many forum member prefer Edelbrock intakes with Comp Cams. Do some research on cam specifications, how high the valve opens, the duration (time open) lobe separation, etc.. As these numbers change, so does the performance of the product. You want as much performance as your existing parts and bank account can be comfortable with.
Do the bottom end means the rotating assembly: crank, pistons, block, and it gets expensive rather quickly.
If your existing carb is an original (Q-Jet), stick with that and as a first step, find a good rebuilder and send it out. A forum member, Lars, is a Q-Jet wizard. I think he is retired but, he may take on a hardship case. Around by me, there is a rebuilder who advertises in Hemmings Magazine under Services. There are others out here, maybe somebody could come back with a recommendation.
Just keep asking questions

 

Thanks for all the replies. I'm torn between trying to make several small upgrades over time or saving up for a crate motor. I just don't want to pour money into engine upgrades that may end of putting too much stress on an old engine. Maybe I should look at getting a carb that would work now as well something that would work on a crate motor down the road. I've been looking at the Holley Street Avenger series.

 

FWIW: You've got something special: the 80 L-82 was the last optional Corvette engine until the 96 models. Why not keep what you have?

 

Mike,

I understand where you're coming from. I'm just trying to see what options I have out there. I realize the 80 L-82 engine is special. If I had a brand new L-82 engine I wouldn't be looking at replacing it but I have over 100k on this one.

 

Is there a problem with the original Q-Jet? If you have a good core, the spreadbore, mechanical secondary Q-Jet is the preferred carb.

With a rebuild, most blocks clean up real well with a .030 bore of the cylinders. If it's the original engine, even if you buy a crate motor, don't get rid of it.

 

Heads first. Cam should match the heads.

 

Absolutely it will. The amount of stress you add will be determined on how much power you add.

If you live in an area of the country that does not inspect emissions equipment then install a true dual exhaust system with headers.

Rebuild and tune the current carb (if factory Q-jet).

Inspect and fine tune the timing on your distributor.

New intake manifold will add a few ponies and isn't expensive.

Actually the best bang for the buck you could install on that car right now is a better gear ratio. Depending on what you have and what you install it could feel like quite a bit of power since the rear diff is a torque multiplier. If you have a 4 spd and don't do too much highway driving then 3.73 to 4.11, but if auto with 3spd tranny then go with 3.33 or 3.55 gears. It will wake the car up.

A cam and heads is far to dependent on many other things going on in your car. Until you have the budget to support the speed habit I would leave the car alone until you are more educated and have a plan. Don't start buying parts based on marketing crap you read in the chevy mags. An engine can run or it can be designed to RUN AWESOME when done right.

 

SG:
I applaud you for recognizing your limitations. If you cannot do the work ... you'll pay lots to have someone install cam or heads etc ... then hope they did decent work?

You might just be better off leaving it alone & save for a crate or rebuild.

that kit 300-502 won't do much for an OE L82 ... it actually has less cam than OE L82 ... and your Qjet carb won't fit that intake. Anyway stock OE intake is plenty for cams in that range.

But if you want to tinker:
If motor has 100K, it'll actually benefit from a new timing chain. Why not get a cheap timing set like cloyes p/n C3023X ?... install it so OE L82 cam is 4 degrees advanced ... that'll close valves earlier & effectively raise compression. Also ensure OE HEI distributor is optimized ... same for OE Qjet carb.

If your motor has thick (about 0.040"-0.050") head gaskets??? ... install thin (0.015") steel shim gaskets felpro p/n 1094 with OE iron heads ... if you have thick gasket, a 1094 will raise compression about 1/2 a whole point. Have shop freshen your OE heads w/ replacement valve springs & stem seals & ... if there's slop between stem & guide ... install thinwall valve guide liners; local auto machine shop will advise you.

*everything on the internet's suspect; including the very words I just wrote.

 

i have an 80 and went down the road you are on. just do the crate now! i spent money on some hop up parts and then decided to build the motor and now i want a stroker motor. should have just done that in the first place and had it over with. I did a lot of work that i could have just saved my money and time and done it right the first time. Trust me you will be glad you did....

 

SG...I know where you are coming from....you want to improve the performance of the existing motor, without having to spring for a new motor or a rebuild. Sounds like money is an issue, as it has been with me....so I feel your pain brother! But MOST of the comments listed above are VERY valid in your situation. You have to take a look at what is cost effective and prudent. If you start throwing on parts that are really meant to be added to a fresh or low-mileage motor, you will most certainly cause the added engine stress that it sounds like you are already aware of. You start mixing old and new parts together, and it's a recipe for not-so-good things. Now granted, some of the components ARE designed to be replaced without the need for a complete rebuild...timing chains....heads....cam and lifters (to a degree), etc. But you start diving in and start upping the performance on those components, and that CAN be a problem. Heck, you might get lucky, but then again you might not.

Given the other comments stated above, I would have to agree with the assessment that you would be happier in the long run if you were to save your money that you would be putting in to the items you mentioned, and save up for a quality crate motor. There are many different performance levels on crate motors, so your best bet is to hook up with a local speed-shop in your area that sells these motors, and see what they have and how much they are. If you are mechanically inclined, you can get short blocks, long blocks, or even the completely assembled motors. I know a buddy of mine has ordered a long block locally, and he got it for around $1200. Sounds like a lot, but when you start pouring money into a tired engine, that $1200 will seem like the best money you ever spent!!

IMO...if you are looking for some performance improvement (working with what you have now) I would spring for a complete tune-up package....cap, rotor, plugs, wires....perhaps a GOOD HEI distributor.....add a good set of headers and even true dual exhaust.......replace the timing chain and gears if they are very worn....perhaps a new fuel pump......and then a GOOD ignition system such as MSD. They are all components that you could transfer onto another block if you should go THAT route, and they will improve the driveability of your car right now. Those things I mentioned will NOT affect, or shall I say, have a negative impact on the other components in your engine. You might just start there and see if that gives you what you are looking for in the short term, and then develop a game plan for the long term Good luck!!

Deja

 

Thank you to everyone for all the replies and different angles to consider. There is nothing wrong with my engine right now so maybe my best bet would be to save for a crate motor instead of dumping money into a old engine right now.

Should I go to a local shop or order somehting on-line when the time comes?

Here's a couple I've been looking at:

http://www.jegs.com/i/GM+Performance...99529/10002/-1

http://www.jegs.com/i/GM+Performance...10007/10002/-1

I live in Iowa and there are not many speed shops around. I wish this were somehting I could tackle myself but without the needed skills and equipment I would have no clue what to do.

 

If you have friends or a mechanic that can do an engine swap for you, consider buying a GM Performance engine. I am sure forum members could give plenty of options on which one would be best for your setup and bank account. The local GM product would help with any warranty issues that may develop. A local product gives the opportunity to talk with somebody in person.

 

I suggest that you tune the engine and carb/distributor the best you can and leave it alone. Bumping HP/torque up on a worn engine is a shaky proposition at best. Since you have a running and numbers matching L-82, why not put a crate motor in for "fun" and rebuild the L-82 back to stock (or a little better) condition for the future. A properly set-up L-82 was no "dog".

 

If oil pressure and compression is good a rebuilt Q-jet, in. manifold, exhaust and a must is the timing chain!!! You should have a good runner as long as you DON'T OVER REV IT!!!!
Then when it does blow or smoke everything you purchaced -timing chain can be reused