Inliners International
Posted By: tom jennings Problem selecting turbocharger - 11/16/08 11:34 PM
I'm building a little Nash/Rambler inline six (195.6 OHV). My target is 175hp (Rambler claimed it was "138 hp" but at 16 seconds to 60, with a 3.77 axle, that seems optimistic). More specs below.

My problem: given a set of turbo specs needed (around 1.3" turbine, A/R around .50, etc) how do I figure out what a likely donor might be?

OK, I need a tiny turbo. Small, slow-turning motor, 4psi boost. Chassis is setup such that you drive this thing 1500 - 2600 rpm. Turbo specs above get me flat torque to 3000, perfect! Bore is 3.125+.040, stroke 4.25 (think beer can!) rod ratio 1.44. Trough intake like the little Chevy motor. Decent exhaust though though long bent path through the head. It's an old Nash design, dropped in 1965.

The low boost is for three reasons: first turbo project, let's be modest. Second gotta work with the current driveline (a T96 3-speed with OD. Last, the really poor head sealing on this motor. (This last is a shame, as the bottom end is all forged parts!)

How do I locate a likely junkyard donor given basic turbo specs? Just comparable output and go with what might fit?

It will get TBI fuel injection as I've got that running on my other Rambler now and I'm confident enough to screw that up all by myself on the next motor.

(I have an old NOS rebuilt unit (1958 short block) I got from eBay this year. It'll get a total teardown and new rings (I'm sure these are all spring out) and a basic balance and reassemble. Got a good head with a recent rebuild but it will get full teardown and inspect. It will get TBI EFI as
The Buick regal turbos are pretty small stock. APPROX 1978-1983 ish ????
Might give one of those a try,you can get them pretty cheap.

MBHD
Posted By: tlowe #1716 Re: Problem selecting turbocharger - 11/17/08 12:01 AM
i agree with hank, the regal gn turbo would be cheap and produce that boost on the small motor.
your motor should handle 6 psi easily. tom
Posted By: tom jennings Re: Problem selecting turbocharger - 11/17/08 03:29 AM
OK thanks. I need to make a junkyard run and see what's what.

So there's no real scientific or repeatable way to find one? Just someone knows what to stumble over? Makes me feel a little bit better at least!

I hate to do all sorts of work to plumb and control one then find out the A/R is way off or something.
Posted By: tlowe #1716 Re: Problem selecting turbocharger - 11/17/08 10:38 AM
that turbo can also produce more than enough boost for the 196 motor. you will have to hook up the wastegate for sure.

if i read you question correct above. you want to operate the engine under boost regularly or at highway speeds? or what rpm do you want the boost to be present. tom
Posted By: panic Re: Problem selecting turbocharger - 11/17/08 08:50 PM
ATMD the rod is 6.825", rod ratio is 1.606:1.
The Buick turbo won't develop any boost until the engine is turning faster than the Buick, unless you run a smaller A/R turbine housing.
 Originally Posted By: panic
ATMD the rod is 6.825", rod ratio is 1.606:1.
The Buick turbo won't develop any boost until the engine is turning faster than the Buick, unless you run a smaller A/R turbine housing.


Does not equate.The early Buick turbine A/R's are small in fact they were too small for REVOD on a 250 CI engine.
Sounds like you know his whole combination?
What cid is 3.8 liter? Too lazy right now.
Posted By: Nexxussian Re: Problem selecting turbocharger - 11/17/08 10:35 PM
3.8 X 61.02 = 231.876
Posted By: Nexxussian Re: Problem selecting turbocharger - 11/17/08 10:39 PM
Still, IIRC the turbine AR on those is real small, around or just under .5 IIRC. It was supposed to spool on the stock 3.8 just above idle (whatver the stall speed of the converter would alow it to flash to basically).

So a 194 should start making boost somewhere around 2K ish +/-.

Of course I could be remembering that wrong.
Posted By: tlowe #1716 Re: Problem selecting turbocharger - 11/17/08 10:46 PM
yep, 1 gallon=3.8L=231 ci. easy to remember
A 195 CI engine is not that much smaller than a 231.
Those early Buicks & Monte Carlos w/the 3.8 turbos spooled up just off of idle & only made 8 PSI tops??????

tom jennings,,,what does your torque converter stall up to,if you know????

I would think a 1800-2000 RPM stall would work perfect on your smaller 195 CI engine,what do you guys think?


MBHD
Posted By: tlowe #1716 Re: Problem selecting turbocharger - 11/17/08 10:56 PM
he is not running a lockup. he has a clutch. it is a stick shift.
current driveline (a T96 3-speed with OD. i think it is a stick. tom
Stick shift is a bit tougher to get low end boost if the turbine A/R is a bit big,but it should still work OK.

MBHD
Posted By: tlowe #1716 Re: Problem selecting turbocharger - 11/18/08 01:01 AM
turbo-6 has another turbo idea that may work. try looking one up from a mid 80's ford t bird. i think they also called them supercoupes. they are for a smaller engine but will spool better and surely would be cheaper yet (more plentiful). tom
Posted By: Nexxussian Re: Problem selecting turbocharger - 11/18/08 05:24 AM
 Originally Posted By: tlowe #1716
yep, 1 gallon=3.8L=231 ci. easy to remember


Dang, forgot all about the gallon correction, maybe I'll remember that correlation now (probably not though ).
Posted By: Nexxussian Re: Problem selecting turbocharger - 11/18/08 05:31 AM
I think the one he want's is the 'Turbo Coupe', the Super Coupe had a 3.8 V6 with a blower on it (Eaton M-90 IIRC). The Turbocoupe had a turbo on the 2.3 I4 (aka 'Pinto', but I understand that one specifically had quite a few turbo specific parts).

Regarless a turbo for a smaller engine would spool earlier.

194/61.02= 3.179 L so a 2.3 trimed turbo might be a bit small. Wasn't there one of the Chryslers in the late '80s - early '90s that had a 3.0 (ish) V6 with a single turbo?
Posted By: Twisted6 Re: Problem selecting turbocharger - 11/18/08 09:25 AM
The Buick Grand Nat. Had a T03 on it.I know I have one sitting here.(Off a v6)I was told sometime back it was good for 6-(10psi max)
Posted By: 56er Re: Problem selecting turbocharger - 11/19/08 12:42 AM
the chrysler 2.2 turbo was a T28. The turbocoupe was a T3-60 on the early cars, an IHI RHB-5 on the 87-88's. The GN's had a T3 super 60.

Remember these engines were probably a little more efficient than the nash. And he doesn't want a high winding screamer of death. A T3-60 off a turbocoupe or an SVO mustang might be your best bet.
Posted By: 56er Re: Problem selecting turbocharger - 11/19/08 12:48 AM
I put you in my turbo calculator. Get a t3-60 with a .48a/r housing from a turbocoupe. I figured your max rpm at 4500. You will probably need 8 lbs of boost. Still okay on stock pistons on a fresh engine.
Posted By: Nexxussian Re: Problem selecting turbocharger - 11/19/08 05:28 AM
Good point on the RPMs.
 Originally Posted By: 56er
the chrysler 2.2 turbo was a T28. The turbocoupe was a T3-60 on the early cars, an IHI RHB-5 on the 87-88's. The GN's had a T3 super 60.

Remember these engines were probably a little more efficient than the nash. And he doesn't want a high winding screamer of death. A T3-60 off a turbocoupe or an SVO mustang might be your best bet.


Buick GN's had a 60 MM compressor wheel? I don't think so,much smaller than a 60.
Buick regals had really small turbos,1978-1982??
Posted By: Nexxussian Re: Problem selecting turbocharger - 11/20/08 05:47 AM
I thought only the last year or two had the 'big' turbo (and EFI). IIRC the draw through setup they had was a smaller turbo.
 Originally Posted By: Nexxussian
I thought only the last year or two had the 'big' turbo (and EFI). IIRC the draw through setup they had was a smaller turbo.



86 & 87 had a larger turbo but it was not that big.

Yes the older Regals had a draw through set-up w/a Quadrajet 4 bbl carb,& yes,the turbo was smaller.

MBHD
Posted By: Greybeard Re: Problem selecting turbocharger - 11/20/08 03:11 PM
I've built two systems using the Early Buick turbo in a draw through configuration.

A manual trans 225 MOPAR using propane for fuel. Standing on the throttle @ just above idle in 1st gear, it would be on the wastegate by 2000rpm @7.5lbs, and stay there through the gears. If you hit the throttle in high gear, 1600rpm, it would go into boost almost as fast as you pushed the throttle. We did a before and after dyno test on an old Clayton chassis dyno. Both using propane for fuel. 96 rwhp NA, and 156rwhp @ 7.5lbs. We tried increasing the boost but the propane system was maxed out and couldn'd keep up. At 7.5 lbs boost it was leaning out above 3500rpm.

I also used the same system on a 250. The boost was instant with it. The carb was a Carter YH unit. Installed in an early Nova it was real strong and pulled to 4500rpm. We played with the wastegate and got pretty bad detonation. Installed a vacumm advance/pressure retard system from Dale Interprises made for the Corvair. It helped some. We later used a windshield washer bottle with built in pump and fashioned water injection. With the wastegate disabled the engine would hit 12-13 lbs boost in low and 16 lbs in 2nd gear and then pull back a little as the little carb was probably not helping @ higher rpm. We never had this one on a dyno.

I'm sure you can find and engine too small for this turbo, but it was quite small for it's intended application, and a 250 would have pushed it abit but for the lack of RPM.

If you'd like a look at what they can look like, I've got pics on my computor and would be glad to e-mail them.
mantle@fmtcblue.com

Mike
Greybeard,
you should post those pics here so we can all enjoy.

MBHD
Posted By: Greybeard Re: Problem selecting turbocharger - 11/21/08 12:43 PM
How do I do that? I'm so old school I forget sometimes that I turn off this thing by hitting "start".
Try this. Almost every thing you learn at Stovebolt works here and their "Short Bus" forum is computer stuff. I'm still in the learning mode.
http://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=471862#Post471862
© Inliners International Bulletin Board