Jchrisd

Let me begin by saying my name is Chris and I own an 81 vette.
I am a dealership flat rate tech for the last 13 years, but I worked for FORD and ACURA, not GM.
Anyway, here is my situation. I purchased an 81 Vette on EBAY site on seen. So I wasn't using my head that day.. Anyway, it is a really nice LOOKING car, but under the car is a different story. To make a long story shory, I took the thing to work, and almost passed out when I put it on the lift.WOW, what a mess.
80% of the mess is now fixed thanks to a saw zaw and alot of new parts and alot of time pissing off my boss working on my own car in my bay.HA HA HA.
Now to get to my first question. Then engine in my car is bone stock, and EVERY LITTLE piece of everything is intact. County Corvette told me it is one of the cleanest engine compartments they ever saw on an 81. Problem I have is that the car is a slug, and I mean slug. The big reason is that the CARB is in need of an overhaul, and I don't mean just putting a rebuild kit in it. I am looking for someone who can dissasemble and properly clean and fix the wells, and the throtle shaft bushings need to be replaces, becasue they are leaking, ect. I am looking fo some suggestions on a good builder at a good price.( electronic carb). I have read about someone named LARS, but do not know how to get ahold of him.
Second question. I was considering giving myself some more power. I figured this.. The engine I think is 8.2-1 CP ratio. I have 76cc smog heads and a very small cam and an electronic carb.
Now this its the tricky part. I don't want the car to look like it was butchered. I was considering putting a set of older heads on that a guy I work with has. I forget the casting numbers, but they are 67cc chambers, and I was gonna use a thin head gasket to raise my compression to about 9.3-1. Approx. Also I was considering the comp xe262 cam or the xe268 cam. Now remember I have 3.08 gears and a stock converter. Has anyone used either cam, and if so, did the car have some torqe at the bottom end compared to stock???
Another thing, I believe that the Q-jet would run as well or better than a edelbrock or holley, if I could find someone to correctly build it. Opinions??
And last but not least. The dist. is an electronic advance, not vacume. If I wanted to drop a vacume advance dist. in the car, how or what dist. wires would I change?? I do not have a manual yet, but am getting one. Just woundered if anyone did it yet. I am aware that it is computer controled, and figure the engine lite will set a code if I don't wire the thing correctly.
Please get back to me with any thoughtful feedback. Remember, I am not looking to build a race car here. I am just tring to maybe keep up with the Acura's I work on, hows that.

Jchrisd

I found 2 places on the net that look like they would do a good job on the q-jet rebuild. The first place is CARB USA which is in Jersey and the next place is THE CARB SHOP and it is in California. Has anyone heard of either place??? WHat about LARS. Has anyone had any work done by hese guys who could give me some feedback..

bobs77vet

first use Lars and i'm running the XE268H and like it your biggest problems is the heads onthe engine really stink....

i'll find Lars email hold on

mailto:
V8FastCars@msn.com

heres a thread also

http://forums.corvetteforum.com/show...172&forum_id=3

BigBlockk

Last I heard Lars won't touch the electronic carburetors. There really is no tuning to them, just adjustments. You can do this yourself. Lord knows if I can do it anyone can. Get Doug Roe's Rochester book. It has everything you need to know.

http://www.ecklers.com/product.asp?p...&dept%5Fid=224

Also you can try I-5 for a reman.

http://www.i-5automotive.com/page5.html

BigBlockk

Later.....

glen242

Had my Q-Jet rebuilt by The Carb Shop about 5-6 years ago, before I heard of Lars. They did a fine job, but, if doing it now, I would use Lars.

Carb is still as smooth as FI, once it warms up. No bogs, surging, etc. But I think it needs recalibrated since I went from the 350 to the 383. Will find out this spring when on ta dyno.

tersian

I replaced my 81 engine with a 383 Stroker, it runs much better now. Best performance mod I've ever done.

http://forums.corvetteforum.com/show...p?p=1552870227

Kalway

Lars won't touch the E4ME q-jet. It's a hunk of junk in my opinion, any ways. Here are my suggestions.

Toss that carburetor in a box along with the smog pump and anything smog related on the car. Also procede to disconnecting that god forsaken piece of crap they call a computer from behind the driver's seat. From there yank that annoying electronic advanced HEI out. Now that those are out of the way get a vaccume advanced HEI distributor on ebay or anyplace you want. Any standard HEI will work fine, I got mine on e-bay for like $80 w/shipping and it's a procomp and works great. Next, take your pick at q-jets for a quick replacement. I chose an Edelbrock 1904 to replace mine with. An electric choke q-jet would be an ideal replacement for you as everything is there to hook it up. You work at a shop so obviously you're going to know how to tune and time that stuff. A good finishing touch would be setting up the switch for the TCC so you can get a few extra miles per gallon on the freeway.

I'd say just removing the computer from the equation would gain you about 20 - 30hp. It brought my '81 to ~230hp at the crank, with a mild cam. The stock cam sucks and runs flat at about 80k miles anyways. Open up the exhaust and put some nice heads on it and you'll be chewing those acuras up.

UKPaul

Aha, it's one of those "Junk the computer" threads :lol In the interests of stubborness I've kept the computer in place on mine. If the system is working OK & you're not after really wild power levels then it should be able to handle some mild tweaking. Assuming that you're going to keep it looking stock then is an exhaust swap out of the question??? The biggest difference in power I felt on mine was junking the stock system (which had a "test pipe" in place of a cat) & fitting 2 1/2" true duals. That's a mod that will put a grin on your face. I also changed the cam to one that was better, but still computer friendly (keeps a fairly high vacuum at idle). I went for a Crane CompuCam 2040 (probably called something else by now) with .440/.454 lift & 210/216 dur 114 lsa. It gave more power in mid & high rev ranges, but nothing very spectacular (I suspect that's because it's due to the stock heads & low CR - the cam needs higher CR & better breathing heads to give best results). What I did notice was that the low end seemed a bit flat afterwards. I got a Hypertech chip from a forum member & that improved it a bit, so started looking at spark advance. Stock is 6*BTDC (must disconnect one of the connectors at the dist when checking) so I set it to 11*BTDC (according to Hypertech you can safely use 13*BTDC, but I wanted a safety margin due to some of the crap fuel I occasionally get). What a difference that made! A very noticeable difference was felt in the off idle response, the pick up was far better than it was & the motor actually felt like it was rarin to go (rather than "Oh OK, do I have to?"). What was even better was that it only cost 5 mins to do! I couln't adjust the advance curve by changing springs, etc, so I just kept the shape of the curve as the chip had decided & advance the whole goddamn thing I fitted a Performer intake but couldn't honestly say if it made any difference. Maybe a dyno would show something, but from the drivers seat it was hard to tell (stock is ally so no weight savings were made). After all this it felt great until high rpms where power would drop off & it felt like it was being strangled. So I fitted Dynomax Headers in the assumption that the stock manifolds (with the 2" restriction) were responsible. There was no difference that I felt at low & mid revs, but the upper end did feel better than it did (it also sounded nicer under the hood ). I think the same effect can be almost gained by fitting the manifolds from an '82 as, I've read on here, they don't have the restriction that the '81's had (never seen a set, so don't know if that's true). DO NOT fit a 160* stat as the computer could throw it's toys out of the pram. The coolant won't get up to the temp the computer is looking for, so it won't play ball. I fitted a 180* stat & it's fine. What else? Minor bits & pieces, but I think most of the above covers the best gains I got. What I was hoping for was to get a set of decent heads on it. When they're on I'm convinced that the cam will perform at it's full potential as the stock heads, cam, exhaust are the major bottleneck (not sure if the intake is really that bad?). Even with the stock heads still on it the performance improvements have made it all worthwhile. At very low rpms it's about the same as stock (which wasn't bad as the L81 has a lot of low down torque), but as revs climb the power doesn't fall off like it did when stock. I was once sitting at some lights behind a stock '80 & when they turned green he gave it WOT. I did the same & at first we pulled away at about the same rate of acceleration. Then I had to let up real quick & brake as I near slammed into the back of him. Where he'd continued with the stock acceleration (ie power started dropping off), mine started pulling harder. I doubt if it's producing spectacular figures (no point in visiting a dyno with stock heads), but it's a lot better than it was as stock.
Not sure if the cams you mentioned will work, but all you need to do is find what vacuum they give at idle. What happens is that if a cam with a lot of overlap is fitted then the vacuum at idle will be low. With a low vacuum the computer thinks the throttle is being pressed so richens up the mixture. Not good!
Lars won't touch the E4ME carb but the stock workshop manual (expensive, but the best manual I've ever seen for mine) gives a good lot of info on setting it up & rebuilding it. Doug Roe's book on Q-jets also covers it fairly well. The throttle shaft bushings can be replaced easily. Somebody sourced me some bushings in the US & sent them over. I just reamed out the worn holes (pivots?) in the carb & fitted the new bushes. Easy to do, just take your time & it will be an easy job. The difference in idle quality after fitting the bushes is brilliant. Apparently kits can be bought in the US that contain the reamers needed to do the job (if you've ever fitted a helicoil then you'll be able to fit the bushings). If you do take the carb apart then note how everything is adjusted as you do it, so that you can put it back together the same. It's not a difficult carb to work on (I did mine in another country with no access to the specific tools gauges needed to set it up), it just needs care & attention to detail. The computer only controls the mixture on the primaries, the secondaries work just like previous Q-jets. After fitting the Headers to mine the mixture was a bit weak under heavy throttle. On Lars' advice I took out the stock CH secondary needles & replaced them with DA ones. The computer had no problem with this & the car ran much. much stronger due to it. The only problem I have with the E4ME is, just like other Q-jets, that stupid, poxy fine thread on the fuel inlet (seen the price of a helicoil set for one?)
Anyway, this forum will tell you to junk the computer, carb & dist. I'm just saying that you can get better power out of it with the confuser still running the show (there's people with much stronger builds than mine who're still running the computer). I wish I was in a position to be able to tell you what aftermarket heads did for it
Sig atached for all mods.

jotto

@ UKPaul

Its nice to see you type the big ones on this forum as well...
thought it might just be the CCCUK site.

MsVetteMan

Junk the 'puter, the smog, and the cats. Change out that POS distrib. and your good to go.

ESC3

You can pull the rebuild instructions for that carb right off the net.You will need a Dwell meter and a digital voltmeter to do all the adjusments and tune it.Be forwarned,for the price of the complete rebuild kit and the new idle mixture solenoid you can buy a brand new Edelbrock Performer.

jrl1973vette

hey i had my quadra jet original carb rebuilt by the carb shop in wisconsin and let me tell you those guys did a great job not to mention anytime something is wrong they are right there for me the guys up here are about 60 to 70, doing it for years and they told me to keep that carb it was a great carb so take that for whats it worth

Kalway

Carter AFB bad! Quadrajet good. Unless you mean the Edelbrock Performer Q-jet #1901, 1902, 1903, or 1904.

UKPaul

No, I just use that one to practice