Quadrajet carburetor on a 231ci V6

[charlief1]

Here's what I would sugest. Find an 85-87 block and heads. They are the best so far from what I have used. Now for the nasty part. The largest oiling hole to the mains is the size that you want for all of them (#1 main). Use a drill and open them up for better oiling to the bottom where most of the problems occur. Get a high volume oil pump kit With thrust plate. Melling is one of the least expensive. I got one from Auto (UGH) Zone. Leave the stock cam in place to help drill out the holes. The only choice for the cam bearings is TA performance. A cam with a .420 lift at valve is a good choice (stock 85/87 GN), but the eldebrock performer plus is a good choice also (.472 exhuast). The intake at this point can be 4.1 or Holly. Both have EGR provisions but the Holly will have less exhaust heating of the intake (Holly and 4.1 will have to be ported for best effect. More for the 4.1.). The early Quadrajets are 630 cfm but since you have a later (750) design you can modify it to reduce the total cfm. Look at the rear butterflies. There is a stop for the butterflies. You can drill and tap a #8-32 or metric equivilant to adjust the cfm on the top not on the butterflies. Don't run the tap all the way through so you have a tight fit. This will keep the screw from backing out. A 1 inch hiker will help you get the best effect from the carb and won't cost to much. Look on ebay and you might get lucky. The Distributor is an entirely different story. The typical advance kit from Mr Gasket is great to get started (use the lightest springs). If you can find it a vacuam advance from a 76 vega 4 banger has the lowest vacuam to help out on the advance. I had a total of 42 degrees timing and used two different carbs. One for street, (76 olds 350) and one for race (68 chevy). The 68 chevy was the one that blew my rear end and twisted the frame. Prep of the engine is the biggest issue. Do you have access to a competant machine shop?

 

[b4black]

The NA and Turbo use the same driver side exhaust manifold. Check the casting number:
Exhaust, Lt - 1263031 (NA is same)

First week of November '78 should be a '79 model. You shoud be in good shape.

 

[charlief1]

Check this thread if you're intersted in a resonble price on a carb and an Offenhouser intake. http://www.turbobuick.com/forums/parts-sale/230284-arp-head-bolts-offy-intake-misc-na-parts.html

 

[willitell]

I have a dual jet if you want it. See the thread charlie mentioned above. Pay shipping to france and it's yours. Was working when pulled, don't know about specifics about the condition or model (I'm at school right now), but I can get you part numbers an pics on friday or saturday.

The Offy I have is for low port heads, close but no cigar. (If other memebers look at the pic of his intake-less motor you'll notcie heads that look very similar to the later ones). Damn.

Let me know if you need anything i've got listed there

If anybody else wants something from my thread let me know i'm willing to deal.

-Will

 

[charlief1]

The 78 is a low port engine Will. That's why I sent you a pm so maybe you two could work something out.

 

[willitell]

I'm just saying it looks eeriely similar to the stock '79 heads I tore off my engine. Don't want to ship it all the way to france for him to have the same disappointment I did.

 

[charlief1]

Understandable. I wouldn't want either one of you to take my advice without checking it out. I'm going off of my experience and the knowledge that I've gathered over the last 20 years. My info can and has been wrong before. PLEASE verify what I have stated so that you can be VERY sure.

 

[SolarGoldRaptor]

I've just checked the casting numbers on the heads, it's 81262098. According to this page it's a 79 head

 

[willitell]

Yeah, so the offy wouldn't work for you. My offer still stands on the dualjet if you want it.

 

[SolarGoldRaptor]

Hi,

I don't know why I hadn't seen your post

Anyway, I'm interested of course but is this a Dualjet 210 with the "D" shaped air filter base or the older rounded one ?

Do you have an idea of the shipping costs ?

Thanks !

 

[charlief1]

The round design air filter is a 2gc rochester and is the better of the GM 2bbl carbs. If you have the "triangular" design carb/air filter then you have the dual-jet. basically it's the front half of the q-jet cut off.

 

[willitell]

I'll take pictures, check numbers, and get you a shipping quote this weekend.

 

[bison]

His car was built in November 1978 which is 1979 model year. Buick used the 2GC on the 1978 3.8. In 79 they switched to a 2 jet. The 4.1 intake should bolt up to his heads with no problem. Ive had several q-jets work that were off Chevy engines. As long as the bleed holes are not the wrong size it could be made to work.

 

[charlief1]

His car was built in November 1978 which is 1979 model year. Buick used the 2GC on the 1978 3.8. In 79 they switched to a 2 jet. The 4.1 intake should bolt up to his heads with no problem. Ive had several q-jets work that were off Chevy engines. As long as the bleed holes are not the wrong size it could be made to work.

I modified a 4.1 intake to fit an odd-fire engine by welding up the egr ports at the center of the intake. You will then need to machine the intake down to make it fit and redrill the EGR so that everything will function properly. The trick to making the q-jet work Is in the jetting and modification to the secondandaries. You will have to determine what secondary opening timing and jetting/needles you need to get the WOT to function without flooding the engine. Ignition timing is another issue that you will have to address. You never have said what you're wanting to do with the car. Resto-mod or???

 

[SolarGoldRaptor]

I want to restore it to its original condition, with some slight modifications on the engine. I'm not planning to drag race but I know this engine is capable of good things with not much modifications, especially the "even fire" hi port heads versions. Having 105hp with a 3.8L V6 for a 2 tons car is a little weird for me. I'm used to the small Porsche 924 2L L4 engine of the same era, which produced around 120hp for around 1.1 ton.

 

[charlief1]

I'm not planning to drag race but I know this engine is capable of good things with not much modifications, especially the "even fire" hi port heads versions. Having 105hp with a 3.8L V6 for a 2 tons car is a little weird for me. I'm used to the small Porsche 924 2L L4 engine of the same era, which produced around 120hp for around 1.1 ton.[/QUOTE]

The
buick V-6 is capable of 230-250 hp or 1+ per cubic inch. The factory intakes are limited so an aftermarket intake and ect are nessisary. If you want to do something different you can use a 4.1 intake and an early dual-jet that looks like a Q-jet. The back two barrels are blocked off, but you can still do all of the midifications as you would do to a Q-jet. Check out Doug Roes book on Q-jets for more info.