Looking for any advice on prices, and or dealers for an engine. Any ideas on engines? I am rather "Bubba" on the mechanics part, I just know I love my corvettes -alot. I have decided to keep my '81 and "beef'er up" just a bit. My objective is to have her alittle quicker and meaner than the stock engine. I am not horsepower hungry, just want her to be respectable to cruise around in. My friend told me to go with a crate engine? Any suggestions?? Thanks -Tim

 

I'm interested in doing the same thing. I'm told a set of duals, a compu-cam and a set of 63cc heads would do the trick. I'm still kind of reluctant to go to all that trouble and it not do what I want. I have duals already and it made a good bit of difference. May have actually releaved to much back pressure.

Any one have any idea what kind of HP gain I might get out of a setup I listed above?



[Modified by KENTUCKY81, 5:44 PM 5/21/2002]

 

If you are in an area that requires emission testing then you have to stick with the computer controlled carb :( If emmisions aren't an issue then you can get rid of the computer, replace the carb and distributer and treat it as a regular chevy 350. If you need to pass emissions then you can either upgrade to a newer fuel injected engine, or mod the engine and get a custom chip for the computer. You can increase the CR a little and put a slightly bigger cam in without needing a new chip. Also replacing the stock cat with a newer perfomance cat is supposed to be a big help. This will be my next investment.

 

If you really don't want to rebuild, then suggest you look at GM crate engine options, can go from the 350 HO, about #2,400, to ZZ4 about $3,500, to 383 HT about $4,200? Would probably need another $1,000 to cover misc expense and installation costs in addition to price of crate engine, but GM crate engines come with 3/36,000 warranty.

 

Do you absolutely want to run a crate motor, or are you open to a rebuild, or whatever's cheapest, or what? I think that a rebuild with a setup similar to mine is about what you want. It makes respectable HP, and didn't cost what a crate motor would. Now, if you want even more HP and want to spend the bucks for it a ZZ4 with true duals and no cats is the way to go. It all depends on what you want to spend. :D

 

I have a friend who is going to do the mechanic work; he said he would be more comfortable working with a crate engine, warranty and all. I guess I just don't know how much the price difference is if I were just to rebuild. Will it be just as sound and reliable in the end? What is an average price of rebuild like you guys are mentioning. I see a crate can run anywhere from $2500 and up. What can $1500 get me in a rebuild? I am totally on the fence as to which way to go. :confused:

 

Hi, Tim,
Here's what I did with my '81. The crate engine is a 355ci, 330hp, 390lb/ft, unit from Summit, and I've been very happy with it, but I don't think they sell them any more. Too bad.

http://www.rogerscorvette.com/free/morris.htm

If I were doing it again today, I would seriously consider a ZZ4 crate motor from GM, and do everything else the same way I did. I would also look for a 406 crate motor, or consider having a local machine shop build a 406 for me. I went with a 355 because I was worried about emissions, but this motor makes less emissions than the stocker did!! :crazy: So I would definitely, seriously, look at a 406. I think the ultimate emissions-friendly crate motor for a '81 Vette would be a 400 built with a new GM 4.125" bore block and all the ZZ4-spec parts... that would probably cost you around $4k, maybe $4500. Just for comparison, I got my 355 from Summit for only $2100! :D But that's probably why they don't sell them anymore - they weren't making any money... doh! :eek:



[Modified by Gator81, 8:30 AM 5/23/2002]

 

I also wanted more power out of my 81. I have decided to take the original L-81 out, seal it, and crate it. Then drop me a built 327 pushing about 400 hp. I think that is the only way to get more power out of a 81, is to drop another engine in them. It would cost to much to try to build them.

BTW, Do you have any pics of your car KENTUCKY81? I also have a beige 81.

 

If you have somebody with experience in rebuilding, or if you can do it yourself, a rebuild is a really affordable alternative to a crate motor. I would say that you would roughly have 500 or less in machine shop fees, a complete 350 master overhaul kit is 155 from Northern (this is the cheapest way to go even though you won't be using the cam and lifters that come with it), get yourself a nice cam and lifters for about 175. There you have a motor for around that 930 mark. You still have a little money left for a water pump, 50, and a fuel pump, 30, which don't usually come with a crate motor that I'm aware of, and you're right at 1000. Still some cash left to go with a performer 2101, maybe some chrome to dress it up, and you're still under 1500 bucks.

There are things like removing the carbon filter from your air cleaner, and running a K&N air filter, and going to true duals with no cats that you will need to do no matter what motor you go with. All of the motors we are talking about need these things to breath.

Now I am perfectly aware that a crate motor is going to make more power than this, and that a crate motor comes with a warranty, but lets take a look at horsepower for the dollar. If I had the extra money I would be running a ZZ4, but I don't, and am real happy with my current motor. I cruise only, no racing, just respectable street power, and it works out great for that without breaking the bank.

That's what I think, and what I do. :) It's your decision on yours though. :cheers:

-Justin

 

Hi,
It all depends on how much hard cash you want to throw at it. If you can afford to put a crate engine in, then go for it (personally I'd go for the most power you can get. The trouble with hp is that you get used to it & then want more :D ).
If the cost of a crate motor is beyond your means (it is for me!) then the L81 can be woken up & perform a lot better than stock. And, of course it all depends on what you want to use the car for: cruising with the odd bit of fun or an all out fire breathing monster to blow the socks off of any unwary challenger!
I haven't got access to a dyno so I can't quote any figures, but what I've done in stages is this:
High output HEI coil & Moroso leads - noticed much better low end performance, felt cleaner/crisper, but the originals could have been past the sell by date?
True dual 2 1/2" exhausts - BIG improvement.
Monza mufflers - seemed to improve it, but if not then the noise was worth it!.
Performer manifold, Moroso lifter valley oil baffle, Crane Compucam 210/216 .440"/.454" (? from memory), Comp cams 1.52:1 roller tipped rockers (not sure if HP increased by them, but it sure sounds impressive down the pub ;) ) - I'm still breaking the cam in, but at low rpm it has been transformed. It feels much, much more responsive & I'm looking forward to the end of the break in period :D
K&N air filter - This alone causes much strife on both sides of the "pond". Some people love them, some hate them. What I do know for fact is that every Bike that I've fitted a K&N to has needed the jetting changed to make it run richer in some part of the rev range (this is a right royal PITA with a bank of 4 flat slide smoothbores, so if I could have avoided re-jetting I would have done). So, more fuel needed usually means more power coming out. If it doesn't, then not having to clean them frequently, or change them, makes them worth the expense (be honest, how many people change/clean air filters when they should?).
After all this the next logical step is to put some decent flowing heads on & increase the CR. I should have done this to get the full effect of the cam, but have run into a bit of a problem with my bank manager :lol:
After that, a set of headers will be required to get the most out of it at high rpm.
Depending on what you do, if you end up with vast quantities of ponies under your foot, then won't the tranny, driveline, etc, need some money spending on them to cope with the extra power?
One question of my own: Over here it's quite common for people to go to a Breakers (salvage yard) & pull the engine out of a wrecked faster car to drop into theirs (very popular ricer trick). Is it possible to get an LT1 out of a late C4 (for example) & squeeze it under the hood? Surely that would be a cheap(?) way of getting a modern engine along with all the peripherals, rather than spending a lot more on a crate engine? OK, it's risky (not much of a warranty) but we took the same risk when we bought our C3's. If the donor car will still run, then at least you could hear the engine. Just a thought :)
Good luck in whatever you decide,
Paul