Inliners International Forums General Discussion Blown and Injected Buick turbo for my 250

Hi my names Scott im a long time lurker at this forum.

I just scored a 79 buick turbo setup that I plan on installing on my 250 with help from this forum!

I found a thread by Greybeard that showed the same setup I have. I've built and tuned motors ever since I can remember but have never took on a turbo install so I've got some learning to do. I picked this setup because for a beginner it seems like tuning may be a little easier than say a blow through.

The 250 for now is stock with a fresh rebuild. Its in a 52 chevy sedan 2 door with five speed OD manual tranny, Jaguar front and rear suspension, the gears are 3:23

What do you guys think about running a quadrajet with this setup? Maybe block off the rear barrels? I can always adapt to something else. I really prefer rochesters and Carters over any Holley any day of the week.

I assume a factory HEI would support this? Maybe a hotter coil and good wires?

I plan on building another 250 or possibly a 292 with a good turbo matched cam, forged pistons, head work ect, but that will come later.


Here it is:




the motor/car:

Run a quadrajet on it. A carb used in a draw thru setup will need to be sized bigger than a carb used in blow thru mode. And that is what it was made to use anyway.
Those are a simple easy way to add boost to the inline 6's. Here is where a water/ meth injection system will really help. Because you will have no intercooler.

Good score.

Run the quadrajet.
Methanol injection. http://mysite.verizon.net/res11pgkr/vehicles/buick8485.html

MSD BTM box: http://cgi.ebay.com/ebaymotors/MSD-6BTM-...=item336caa3ea9

Make a downpipe as straight as possible mandrel bends http://cgi.ebay.com/ebaymotors/3-45-180-...=item2314ebdd6c

& 3" would be a good size w/a straight through muffer design.
Just an example: http://cgi.ebay.com/ebaymotors/Thermal-R...=item45fd911377

I personally do not like the sound of a turbo car w/out a muffler & most people I talk with, pretty much agree, an exhaust system w/out a muffler sounds like a$$.

Plus cops will give you a ticket for being too loud w/out a muffler. Also, some tracks will not let you race if you are too loud & have no muffler.

Stock intake modded, or better yet, an aluminum OFFY intake w/a aluminum adaptor plate to make a hole in the center of the plate
& 3 holes drilled & tapped, then bolt down your turbo compressor housing to the adaptor plate.

No reason to block off the secondaries on a quadrajet.

Here is a good read on how to mix & match turbo hot air turbo parts.The Pontiac 301 set-up has larger components for the most part & flows more air.
http://www.turbobuick.com/forums/before-black-non-sfi-tech/274489-all-turbos-not-created-equal.html

HEI will work fine.

I seen an old 1978 Buick Regal @ the street races years ago haul some butt, an old hot air set-up (non intercooled) Same as your set-up.

Anymore questions ask away, glad to help a fellow inliner.
MBHD

Here is a LINK to some pictures of a 292/turbo project I started. My plan is to use a GM TBI on it and a Megasquirt to control fuel and ignition. I ran into some snags and other projects have come along. The intake manifold in the pictures is a modified stock unit. I now have an Offenhauser 4 bbl manifold with the center opened up and am making an adapter for the turbo. The exhaust manifold is a stock big truck with the 3 bolt head pipe flange. It's just a mock up but maybe it'll help. A good quadra jet is a good way to go. Beater

Thanks for the info Guys.


Beater thats very similar to my later plans. I spent a good portion of the night reading over the megasquirt info at DIYautotune.com later plans will include a tbi setup very similar to that. The car has a long ways to go however.

I think most quadrajets are rated at 750cfm and up, so it may be a bit much carb for the 250, thats why I was thinking about just using the primarys...Similar to a "DualJet" But then again I suppose the original V6 this setup came from used a quadrajet so it must work... I dunno, I will try it both ways as I've got several laying around.

the quadrajet carbs for the V6s had a smaller CFM rating then that of the V8s.

Here is what a Pontiac sprint 250 inline 6 engine used w/P.N.

7028260 '68 A, F, OHC 6-cyl, auto trans 4M 750 cfm

http://highperformancepontiac.automotive...etor_chart.html

MBHD

Remember that all that extra hot air from the turbo needs fuel in it. Your pistons wont like a hot dry mixture. In a draw through the fuel does some cooling and as Tom and Hank pointed out water/alcohol injection is a good thing. Basically your 250 is much bigger and must be fed like a bigger engine.

I alway thought the sprint 4bbl engine had smaller Q-jets & also the Buick Regal turbo V-6 3.8's did also.

I used to see plenty @ the junk yard years ago & by just looking @ them , they looked like a normal sized 750 or so Q-jet.

MBHD

That makes perfect sense. So how would one go about injecting water/alcohol with this setup? through the top of the carb or through the intake? I've heard of people making their own injection which sounds like a fun project. Im really excited to get this thing going!

I've messed with these q-jets,,, the cfm war isn't fair on them,, there are basically two types of bodys, 750's and larger 850 and up,, you can tell by the bump in the venturie, big bump = small, less of a bump = larger version, but the q-jet is basically an air pump, it will feed the amount of air any givin engine will demand, the trick is supplying the fuel for that demand, thats why we see these carbs the '750' version on anything from sixes to big blocks,, the fuel is supplied thru the metering rods and jets on the primary side and a set of quickly changed secondary rods,, the trick (or gigantic headache)is the speed and travel that the secondary flapper door opens,,(the choke looking thing on the secondaries), it is adjustable by a hidden spring and a set screw set into the body for further adjustment over the factory tang,,,typically the door flapps open way to fast,, and that is the "bog",, if adjusted properly it will kick in smoothly,,,
There is a turbo piece for the q-jet,, if your carb has an APT,, you need to make sure the base plate does not have the vacuum orifice to actuate it in a certain position, I fought this forever in a non turbo app,, I had swapped basses for linkages and fumbled for months,,Cliff Ruggles clued me to this,, great rebuilder,, and wrote a great book if you get into these carbs,,,

Dont get me wrong theres nothing new to me about Q-Jets, just the turbo part lol... I remember as a kid driving a beater camaro we'd adjust it so that it would bog between 2 and 4 transition cause back then we thought it sounded cool! I also love the Carters and Edelbrock square bores. The turbos suppose to be here Saturday, I'll start on it then.

You could install the methanol injection nozzle right @ the 3 bolt flange adaptor.
The methanol injection pumps run about 200-250 psi, so it's going to spray into your intake manifold regardless if you are boosting 30 psi or just 6 psi.
http://mysite.verizon.net/res11pgkr/vehicles/buick8485.html

MBHD

Great information on this board!

Another couple of question, Later on if I decide that I want to upgrade the turbo to a bigger unit what would fit the manifolds and is still draw through, where would be a good place to look?

The information provided by the seller say: TB0304 A/R .42/.82 Garrett T type...

What do the numbers breakdown to mean? Thanks in advance. It arrived to me a day early, it should be waiting for me on my porch as I type this!

I also learned by going to the "before Black" Buick forum that the quadrajets that came equipped on these motors were handicapped by the factory because of their larger size. Supposedly the rear barrels were altered to not allow them to fully open. Dunno just what I read...

Very interesting, and I believe it. This does mean that the WOT position of the secondary rods will be different from a normal QJ, needs more R&D.
In 1967 (?) the same Pontiac motor was offered in the GTO and the Firebird: 400", hydraulic cam. It was rated 325 in the 'Bird, but 335 in the Goat.
Why?
Because the 'Bird secondary linkage did not open to 90°, which reduced max power.
This was obedience to the official GM policy of "1 HP per 10 lbs. of weight, for everything except Corvettes".

I have seen factory manifolds that will not allow the secondaries to fully open on a Q-Jet carb.
IIRC Pontiacs & Buicks had them?
As far as I know the carbs (Q-Jets) were not any different than a regualar Q-Jet.

MBHD

IF thats the case then there's a good chance that this one does just that... It came today I've only had to time to unpack it.. I'll check it out with a carb on it tomorrow and report back.

Just a little mock up with the turbo to give myself an idea of how much room I have to play with with pipe plumbing and what not.

I'll have to reclock the turbine inlet so that it points down, its amazing how close a fit it is with the stock intake and how little the intake will need to be modified. I'm going to start building some simple brackets to help hold it in place.

Yep, looks clean & simple to use & install.

This is the reason I always recommend for guys to install one of these set-ups to get there feet wet into the turbocharging world.

Is that the factroy turbo carb?
Does the secondaries go full open?

MBHD

No its one I've had put up in storage for a while. The Secondaries do fully open with the intake.

What do you guys think about running the oil return to the pushrod/lifter covers instead of the oil pan?

I dont see a problem with that. Just be sure to give it ample size to easily drain.

Great I think I'll do that then.. Id have to pull the motor to get the pan off, so it might just save me a little hassle. So whats nominal sizer for a drain? the piece that bolts onto the turbo looks to be about 1/2" diameter.

scottyd, exactly, that's what I was trying to say, the flapper door is opened by the sucking of the engine thru it, if u held a qjet in ur hand and opened the throttle the flapper will not open unless you move the stopper arm on the passenger side of the carb,the secondaries kinda bind like they are stuck, the door opening speed is the wound up spring, a loose wind and and the door flaps open and you get a bog, tighten the spring and vacuum draws the door slowly open allowing the engine to digest the heavier load, right by that spring the is a tang the restricts how much the door opens at all, some are bent some are shaved for more travel, and others have drilled and set screw in the base for adjustment,,the more the door opens the bigger the carb,, the secondary rods always move regardless of the flapper speed and travel they are on a cam that rotates them out of their orifices, there are a massive selection of rod sizes to match carb needs,,

great info Fingersix I will keep all that in mind when I get to the tuning stage.

Did i ever mention Doug Roe's rochester books? Find them at amazon, the first printing (1971?), I think, is the best as it has a bunch of mono, and model B one bbl stuff too. His book predates anybody's q-jet info.

Mostly made in the 750 size with a few 800s (some buicks and Pontiacs for sure)only diff is on the primary side. Air valve is an easy adjustment there are "wind-up" specs available to get you in the ball park(if they are too "loose", they will bring a 455 to its knees). All the back barrels have a pair of 2.25" (57mms in Weber talk butterflies, the 750 jobbies have little 1-3/8" butterflies (35mm)for real nice stumble free low end performance.

Doug shows you how to bore out the accellerator pump well and install a larger accel pump out of a 2GC (po' boys 50 cc holley answer). Most back bbls have a spill port which comes in when the back bbls are opened (Q-jet version of a "double pumper") Not too many trick hot rod Holly features are missed or not incorporated in a stock Q-jet (rochester dont need to advertise this stuff 'cause the sell every one they make to GM). The back barrel meetering rods have different cams to change the lift rate of these rods (thus richness per throttle position).

Doug's book says the models on which the air valves/sec butterflies dont open all the way were done that way to even-out a distribution problem that a particular manifold had-- not to restrict the airflow. The air valve and its shape would then try to direct more airfuel mixture towards the front of those manifolds--Didn't Ruggles ever say that?

They are VERY good carbs- just study them a little. BUY DOUG'S BOOK.

I'm not the Pontiac expert, but I dont think thats the real reason for the hp change. Pontiac had 2 or 3 smooth idling cams for the 400s, the 067, and the 068 cams come to mind at the moment. these and posible exhaust manifold/exhaust pipe configurations I think are more feasible for the only 10 hp diffs.

The carter AVS carbs were just AFBs with a Q-Jet-like Air Velocity Secondary control (adjustible upper butterfly"flap") but on these carbs the diff in primary and secondary butterflie was not so large as Q-Jets, so not near so critical, but these could be adjusted to bring in the sec real smoothly (important to some folks). On early'67 275 hp 327 chevys, some came from factory with these AVS carter AFB looking carbs, the rest had Q-Jets. Since virtually all of GM engines were using the Q-Jet, rochester was having a tough time producing enough to go around. Ultimately GM had to farm out some Q-Jet production to Carter, thus you will sometimes find a Q-Jet with words like "...manufactured for GM by Carter..." on the side of their float bowls. Same carbs

Great info Preacher, I'll def check into that book.

here's what i've toyed with

http://s42.photobucket.com/profile/6pac2go

Have you got it running yet?

It is so simple to install, most all the work is done, mod the intake for the 3 bolt falnge, I believe you might need to reclock the turbo, run a feed/exhaust pipe to the turbo downpipe from the turbo.

Route an oil feed line to the turbo,, most important thing & probably the hardest part, the oil return/drain line into the oil pan.
And other misc stuff.
Might need to heat up the plenum w/water. To help w/cold weather & better driveability.

Get'er done!


MBHD

has been reclocked 2 clear intake

http://s42.photobucket.com/albums/e320/6...pg%26newest%3D1

tube beside the turbo (exhaust) inlet is the oil drain. the turbo exhaust is 2 the back and kinda close 2 the intake. if you look at pg2 of scottyd's pics #4 you'll see the the turbo intake (for exhaust) is aming over the valve cover on his setup. also i'm making my own 4bbl manifold (2 the turbo) so that it's not sitting sideways but straight on like it would b on the engine.

If you align the intake mount to the top bolt and try to match the port size you get into the exhaust heat part of the manifold. Much filling will be needed. I think it would be easier in the long run to build an adapter plate for a four barrel manifold.

X2,
plus, I always look for ways to remove weight from my vehicles.
Aluminum VS cast iron intake,, aluminum better choice for sure.

MBHD

Ok... believe it or not this thing is running. lol

SO i went off the deep end and decided that my little Buick turbo wasnt complicated enough so I topped it with a mid 90s model TBI injection Harness is a modified 94 c10 chevy
ecm is a 16196395.
Just got me a Moates ostrich to help me tune it such a fun project.



I am already thinking about going mpfi, I would like to keep it all hidden to keep the car looking somewhat stock.

instead of making a J pipe to connect to the turbo I reworked the manifold by cutting a new outlet on top of the manifold between the last two exhaust ports then I capped off the original outlet. I like this better than a j pipe and I will eventually build a header that's similar.

My original thinking was to split the manifold run the turbo off of 3 cylinders and run the other three on their own exhaust for true duals.. but I am not sure if 3 cylinders will spool the turbo up sufficiently.

Looks good!