Inliners International Forums General Discussion Blown and Injected draw thru turbo

Any one have any experience with trying out an old school draw thru setup on a chevy six? I don't want my car to look too modernized and I have seen pictures of draw thru setups on stovebolts (235) and even a couple of old ads for them so I figure this would be my best nostalgia type power adder. Only looking to hit 200hp, don't need much more.

I have had very good success with a draw through setup, as pictured in Leo's book. But now that you are able to purchase a exhaust manifold from Spa you can build a simple blow through setup easier by using a simple carb and manifold, no intercooler needed. Easy 300+ HP. And it will look old school! With a draw through you need to build an intake.

Harry

Page 142 ,correct?

MBHD

the bad news is the SPA manifold is only for the newer 230-250-292 engines. tom

Don't forget the 194. ;-0 or the 215;-)

I think something like this is your best option.
ebay draw through turbo

Yea, I'm always thinking 250-292, on an old motor a draw through would be easier, but would be neat to try. I think the combustion chamber would lend itself to turbocharging.

Harry

Well luckily (or unluckily) a 250 is what I am switching to due to the crack in the block of my now deceased 216. The 250 with a turbo swap was my initial plan, but I did not really want the expense of a blow thru carb and figured the draw thru basically tunes itself. Fabricating the intake and exhaust manifolds are not that big of a deal to me since I have full access to a manufacturing machine shop (not engine) and at least fair fabrication skills. I would like to go the least expensive route possible since I cant afford any other. Can you give me any description of what type/size turbo and what type/size/modifications carb works for your combination so I can try to figure out what type of stuff I have will work?
I'm a newbie so I don't know what book/catalog to find the pictures in.

Give this a try
http://cgi.ebay.com/ebaymotors/ws/eBayIS...%3AIT&viewitem=

Looks simular to the Buick Regals 1978-1981 or there abouts
here is the car
http://cgi.ebay.com/ebaymotors/Buick-Gra...5fCarsQ5fTrucks
Repost

MBHD

spd hammer,
alot of turbo choice depends on what your goals are for the engine.
you said 200hp was a goal. that can be achieved without a turbo.

if you want to pursue the turbo idea. a blow thru system is a better choice. the drivability will be better and you will be able to intercool the air. a 60-1 turbo should be a very good choice for a 250 cu motor. tom

I'm ok with the blow thru idea but the problem is the carburetor. I don't know how to modify or tune a carb for a blow thru system and certainly do not have the money to buy one. I should have said before, I have a 51 Styleline with stock 3 on the tree and stock closed drive line so I don't think that combination will sustain over 200 rwhp but I would like to be able to crank the boost up once I am ready to switch out to an open driveline. Plus it seems to me the cheapest way to go about achieving the performance I want would be a turbo since I can pick up old turbos cheap, fabricate the manifolds myself out of free materials, and I could use one of the many Holley carbs I have laying around if I go with the draw thru. It seems everyone I know who knows anything about turbocharging is running fuel injection or a high dollar carb designed for blow thru or some big dookie looking box around the carburetor which seems to give them more problems than what it is worth because of lack of accurate atmospheric reference for the carb. That is why I am looking to a draw thru.

no need to reinvent the wheel. here is a turbo setup ready to run. it is in the classifieds here on inliners.
he is asking 550.00

Rebuilt Buick turbo that has been installed, run, and owner found the turbo was not his problem. Has test miles only, no slop and minimal carbon discoloration to the turbine wheel. The turbine housing has been reclocked for installation on a Chev 6 manifold, but not tightend completely so that the clocking can recieve any final adjustment. The factory Buick intake manifold that bolts to the compressor housing with rebuilt factory q-jet. An adapter to mount side draft Carter YH carb, a rebuilt YH for a '66 Corsa, and a painted style Corvair turbo airfilter housing.

E-mail me for pictures.

Other than the pan removal to install a oil drain, this is a quick, easy, reliable way of adding power to an inline.
Contact Information

greybeard on this website. he can tell you which parts to use for a cheap setup.

I just deleted the ad as the unit is SOLD.

However, I'd be glad to send pics and an explanation as to how to install one on a 6. The only issue that I see in a pre '54 engine is they are a dipper oil feed and I don't believe @15lbs oil pressure they'd have enough oil/pressure to properly feed the turbo. The later 235 is a bolt in and would have enough oil pressure.

greybeard, can you do a writeup in another post. i think it would be great info for the beginner turbo guy's. tom

It is sitting in my post office box in Sumas washington...just waiting for me to get a minute to pick it up!

Thanks again Mike!

Rob,

Ignore the e-mail

Mike

Tom,

I've got a few pictures that I can use if we can find a way to post them, and I can descibe the mods needed to use the early Buick GN turbo on an inline. I'll also be glad to work with anyone to get them through the process. It's pretty simple on the later 6, and works well and using a side draft carb is quite compact. If under hood height is not an issue, the factory q-jet can be used, and the factory Buick carb top/remote filter works to allows for a reduced height.

Mike

I've used the Buick unit on a 225 mopar using Propane as fuel.

I was looking into the turbos from Trans Ams and T Types, but then I figured a turbo from a Conquest or Starion or even a Volvo may also work and I can allocate any of the above for free or really close to it and rebuild it myself. Some one told me a while back that the main difference between a turbo set up for draw thru and a conventional turbo is in the carbon seal. What modifacations are really required?
Not really knowing anything for sure about this setup I figured this forum would be a good place to learn. Looks like I was right, so tell me what you guys think of this plan and what should I change.
My plan for my 250 was to run a tubular header with the turbo mounted below the intake manifold. The a sheet metal plenum chamber seperated into two havlves internally but appearing as one piece externally; the outter half would be the intake chamber below the carb running straight down to an elbow to the turbo inlet with the discharge pipe entering the pressure chamber of the plenum from the bottom and from the pressure chamber of the plenum would be my three intake runners. (metal fabrication is not an issue for me at all) I had planned to run the oil pressue line from the oil filter adapter and just put the return thru a simple bung in the side of the oil pan. I was also planning on a rather conventional 4bbl Holley 600cfm carb, likely upgraded proform body with probably #72 main jets. For boost control I was going to use simple atmospheric venting thru a small air brush pressure regulator on the reference side of the wastegate.
I know it sounds like I am being super cheap but thats because I am; if I have no clue what I am doing I don't want to trash a bunch of expensive parts. (plus the fact that mechanics don't make that much round these parts when you have a one income family) Does this sound like I am on the right path?

Those turbos you are mentioning are too small (Conquest or Starion or even a Volvo )

If you are saying you are super cheap,,, I do not understand why you want to spend money & time on a custom intake & exhaust manifold???
You can use the stock stuff for the power level you are aiming for.

Two cents thrown :-)

MBHD

Just the feedback I was looking for. So I what about a T-72? Would that be (by your experience) too big? I do not know the limitations of volumetric efficiency of theese engines. I'm thinking with the port design the airflow #s, it would not lend itself to supporting any mass ammount of air/fuel. The custom manifolds would essentially be free because I can get all of my materials and consumables for free and it's just my time which I can't really find anything better to do with. I am an ASE master tech and L1 advanced engine performance specialist and make damn near six figures working on everything from Geo s to Benz s and repair turbo cars all the time, but can't engineer a single turbo setup on a carbureted 250 by myself. Kinda ironic ain't it.

A T72 is pretty big,really overkill for the power level you are looking for.

A nice 57 MM compressor will do fine & let you make more power later if you want..

A turbine A/R of .63 or (T3 turbo) smaller will work,smaller if you want to spool up quick.

It depends on if you use a T3 or T4 turbo as they flow different.

A T3 .63 turbine housing will flow less than a T4 .63 housing.

MBHD

I appreciate the guidence since this is new territory for me. I have built many V8s (mostly Pontiac and SBC, and usually went naturally aspirated with nitrous. I now find myself wanting something I have never done before; hence the turbo straight six.
So an old Chrysler turbo may work, since that's a T3. I know the one Volvo turbo I was looking at was a T34 and a Conquest (which my buddy has one which no longer runs) has a T42 (or at least this one does, may be an upgrade 'cause I think I remember them having a T3 based turbo originally).
So I just need to figure out the compressor size and the ratio for any of theese and see if it is inline with the specs you are giving me.
Like I said before I am pretty much experimenting at this point and if I get onto something I can go further later since too much HP now is going to blow my drivetrain apart.
I will save the T72 I have laying around for later.

Do you have any ideas on where I could find VE numbers for the Chevy 250 so I can calculate the plenum area I will need?

For the T3 Chrysler or Conquest turbos,there exhaust/turbine housings & turbine wheels will be really small for a 250 CI engine (chokes the exhaust alot)

Post a pic of your T72 turbo & specs when you get a chance.

For a plenum area, really not necessary,& really have to calculate for 200 HP,but there are formulas available.

Really there is not just one correct formula that I know of to calculate plenum volume.
But here is a good design & info for a Supra
http://www.fabworks.com/assets/pdf/Supra_Plenum.pdf

MBHD

The guy I got the turbo from (in trade for a set of tires) gave me theese specs on it:
Turbonetics HP72 T Series
P Trim .68 AR

I don't know enough about turbo's to know how to confirm any of it. I wanted to use it as a rear mount on my F250 but figured that may not be as easy as I thought so I gave the turbo to a friend of mine who wanted to use it as a rear mount on a Camaro but never got an engine for it so I can get it back from him if I want to use it.
Started thinking about the thing you said about stock stuff and realized you were not talking about ditching the turbo, just running an adapter to the intake for the charge pipe. Brilliant! (don't know why that didn't sink in before)
I think that may be the ticket for me. So with that in mind I guess my search will definitely be on for a Buick turbo. If I can manage to not screw up the intitial, super simple setup then I can move on to something more elaborate.

The 72 should be 72mm major (exducer) diameter for the compressor, you would have to take the compressor housing off to measure that. There wasn't a tag on it anywhere?

72mm being just under 3" you would be making a fair ammount of air. Do you remember what the trim on the turbine is and the A/R on the turbine housing.

It might be too big for the application you have in mind (ie will take a mont of sundays to spool).

If it has a divided turbine housing you could use a diverter to help it spool, but then you'd have to buy one.

that turbo T72 is really big! way too much for a street engine. you are correct , look for a cheap buick turbo. tom

Dont want to step on anyones toes but i think a 250 cui engine would not have a problem spooling that T72 , especially with the P-trim wheel and 68 housing. I spool a T76Q with a 1.15 housing pretty easy, just remember the tune is really important when using larger turbos.

Bosanova,
a 250 would not have a problem spooling up a T72 & it could be fine for street use for a well sorted engine & supporting items,but,,,,,, he is looking for only 200 HP

I thought you cannot get full boost in first or second gear?????
To,me, ,,,,,now this is just my opinion,,,,,,,,,,,,,,,,,,,,,,,,that is not considered spooling pretty easy..
Not knocking you down or anything like that,,,,but he is only looking for 200 HP & a T72 would sorta be a waste.

I chat w/a guy in Brazil that ran a big turbo on his 250 6 cyl & he cannot make full boost until 4500 + RPM,but his car is made for top speed.

Having to get to 4500 + RPM to get to full boost in a street car is not a street friendly car in my book.

Bosanova,we like to have more input from you, you need to be here more often...

MBHD

Yes i understand, if he only wants 200 hp then a much smaller turbo is better. I also think he should aim a little higher like 300hp . BTW i think i got that spool thing a little wrong in my tread, i get full boost in 2,3,4 but not 1st. 1st gear is just over so fast.

Wow, I really started a good topic for discussion here. Why only 200 rwhp? Because I am still running the stock drive line and don't think a closed driveline like that will support much more, but I do think I could get hooked on this turbo thing and try the larger turbo with full custom manifolds when I do change to a conventional open driveline. For right now I think I will do the simplest setup with the stock manifolds. But I am going to build custom intake and exhaust while the engine is out of the car. The biggest thing I will need to learn is how to tune it right and if I am running low boost and a simple carb I think that may be easier. I found a Buick turbo at a local junk yard for $125 and think I will buy it. Fabricating mounts to the manifold should be easy.

If you are going to feed 200HP to the stock drive line it will not stand it. Many years ago (early 60s) I ran a 53 chevy with a built 235. It would run with the superstockers on the 1/5 mile tracks but on a full 1/4 they came by like a freight train. It impressed a lot of people BUT I blew 21 transmision in eleven months, ripped the rivets out of several clutch disks and lost track of the Ujoints and bells I replaced. If you are going to build a turbo and use it, change the drive line first. It will be cheaper in the long run. The original drive line was designed to be driven by a little old lady with a max of 150 horsepower. If you take the transmission apart you will find the cluster gear has bushings not neeedle bearings, also the u-joints are bushings not needle bearing joints and the list goes on. They worked very well for a car driven with a little sense but they won't stand much abuse. If you do retain the stock drive line build a good scatter sheild around the flywheel clutch and transmission. You have never lived until exploding parts rip holes in the floor board right where your legs and feet are. That is where rules requiring blow up sheilds came from.
Sorry for the book but I don't want to see anyone hurt.

The stock bellhousing will not bolt up to the 250 so I have to use and aftermarket one for a 4 speed with and adapter plate, so I am going to use a blow proof bell housing since I do intend to change the drive line...when I can afford to. In the mean time I can just turn the boost down (which aside from being cheaper than extensive internal engine and head work) is why I am going for a turbo. I am a hot rodder but not a racer so I just want to be able to drive the car so to me it makes more sense (and I guess it really doesn't make that much sense in the regular world) to put the turbo on the engine before I put the engine in the car (stock 216 broke) and then drive it until something breaks then replace that. I can't see having the car sit until I can afford the driveline. I will run the stock stuff until I physically can't because its already there and that makes it free.

As far as the horsepower figure, I just don't want to be scared that I won't make it across that intersection or worse yet the kid in the bone stock civic will smoke me at a light.

As I understand it there is a Trail Blazer rear or Exploder that is the right width (10.5 10 bolt or 8.8 Ford) either will be more than strong enough for the power you describe.

I missed the '200 Hp' statement earlier. If you have a full pressure 235 with the full flow filtration coversion, you should be able to support more than that. How much more, I'll leave to people more expert in that than I.

What would you like for a transmision, manual or auto?

I have a bone stock 250. I don't have the expendable $$$ for head work, lumps, cam or any of that and figure the turbo is going to be the best HP per $ ratio of any part I could possibly get short of nitrous.
I just got a bell housing, flywheel and trans for free (4sp rock crusher!!!) so I may look into the Trail Bomb or Exploder thing since those rears should be readily available and I could get a driveshaft custom made from Speedway for like $100, which fits beautifully into the budget this car is being built under. Thanks for the tip. With the open drive line I may shoot for a little higher HP goals.

Yeah, recycled turbo = best hp per $ (if you do the work youself).

You got a Rock crusher for FREE??? You lucky devily you.

I can't even find anyone locally that's willing to sell a muncie (in any condition).

Lucky me has a best friend with a car farm. We happened to be ont the topic of me needing a bell housing and flywheel and he told me there was one out in the field. Trans was under it. Flywheel next to it. (Flywheel going to macine shop)
He said it came out of a 1 ton so it has a granny gear but then again he also gave a friend of mine a 283 that turned out to be a 400... so I I will check the #'s if I can find a site to but it's definitely a muncie. But it turns and was full of lube.
Guess if I run this bell housing now I need to build those scatter shields.
I have been looking into the other forums on the site and it seems that the Edelbrock 600 I have sitting around may work on my 250, but that would probably work best only if I got a 4bbl intake and went blow thru correct?

As I understand it the Studebakers used to do a blow through with the Carters, there's info on how to tune them for blow through in that application (on a 289 V8 yes, but that should be closer than some of the '350' V8 data out there).

How the Carter data would translate to the Edelbrock I am unure. I'm not 100% sure what size Carter they were using, so that would be the first thing I would look for. Though with blow through you should be able to use a somewhat smaller carb (not saying you want to, just saying on the street you could likely get away with it).

I remember a picture credited to an R-5 Stude that showed an air line from the carb hat to the air side of the fuel pump to boost reference that (I've seen that doen on Blow through VW's with some success too, you just have to make sure that side of the fuel pump is sealed from the crankcase). That would eliminte the need for a higher pressure pump and a boost referenced fuel pressure regulator (less $$$) if the back side of the fuel pump is sealed (or you can sort one out).

I think the Carter & Edelbrock carbs are very simular if not the same carb, w/minor differences.

IIRC there are books out there on how to run Holly carbs for blow through application.
You need the plastic type floats,so they do not collaspe under boost pressure & other mods to be done.

I used three DCOE side draft Weber carbs,because there shafts are sealed & do not leak under boost pressure.
I believe not all Weber side draft carbs are all sealed shafts,so you need to shop for the correct one.

Higher pressure fuel pumps are not that much $$$ & if you are only going w/5 -10 psi boost pressure a Holly or other higher pressure electric pumps will work.

I used a Holley Blue pump that had a pressure of 18-20 PSI IIRC.

I only saw up to 10 psi of blower pressure.
I also used just a cheapo Holley regulator w/a boost ref line to the top of the diaphram area that was sealed off,easy set-up & low dollar.


MBHD

Came across some one who wants to trade me a turbo new w/lines and external waste gate. Here is the info I got tell me what you think.
T3/60
4" inlet
2.5"outlet
Compressor .70, .60t wheel
Turbine .63
Exducer 2.2
Inducer 2.58

Sounds like it will work for you.

The turbine wheel is a bit small if you are looking to make a lot of HP later on.

Was this for a 4 cyl engine?

MBHD