Inliners International Forums General Discussion Hi Performance Turbo 292

Hi all, Im new to this board and to the whole mighty straight 6. What I have(will have) is a 292 straight 6 that will be put in a 1950 chevrolet pickup. I could go the usual route of dropping in a small block and calling it done, but Im ready to be different. I want to turbo the 292, which is fairly common I think? I've read these fourms and done searches for maybe 8-10hrs so far, and I've come up with alot of good information, and questions. I'll try to keep this organized so that hopefully I can be helped...


My goal- I have no hp or tq goal in mind, instead I want an engine with very good power, and can be coupled to a 4 speed manual. I hope to run around 8 psi, but have alot of head room to be able to really pour it on when Im ready.

Confusion starts now...

1.) I want to run a carb. This is set in stone. The truck will be very old school "rat roddish", so no efi. I've read that running air/fuel mixtures through the turbo and innercooler is bad, so that means I need a special carb that can handle boost...what carb(s) can do this?

2.) I see that their is an exhaust manifold made that has the special provisions for a turbo and wastegate, but its really $$ and I know I can make one myself if I know what to build it out of. I was thinking getting a steel tube header...cutting it down and modifing it so that the runners are super short into a piece of box tube that connects them all. The turbo would bolt to the box tube. Since it would all be steel I figure I could have it jet hot coated and call it day. But would this work? How thick of tubing would I need?

3.)From what I've seen you either need a blow off valve on the intake or a wastegate on the exhaust. I'd rather have a blow off on the intake for the loud noice it makes(call me dumb), whats the downside to running a BOV on the intake and nothing on the exhaust? I could see overspooling the turbo, but if I select the proper turbo this should never be a problem, correct?

4.) I guess I'd just run a 4 barrel intake manifold. Clifford is $$, so maybe an offy?

5.) Want internals would HAVE to get changed to run 8psi? Im not worried about getting all the power I can possible get out of the boost, not from the get go, so if I just do a fresh rebuild with stronger valve springs, minor head work, and a new cam will I be alright? I understand the stock compresison ratio to be low, so that should be no problem, correct?


I will say thanks to anyone and everyone that can lend a hand. As I said Im very new. I've been around cars my whole life, but 6 cylinders are new to me. So any help is appreciated...thanks.

use a holley, they can be modified to take boost. i do not know how but others do. a manifold would be easier. a header would be hard to keep sealed, i had trouble with headers on a naturally asp setup. could never keep them sealed. i also say a bov and a wastegate. i have both and they each have there own purpose. when you slam the throttle shut while shifting under boost the bov keeps the hoses from blowing apart. the waste gate will give you precise control when set to a pressure you select. although mine is having a problem called boost creep. my boost still rises even with the wastegate open. i'll get that ironed out later. as for internals forged pistons are a must with thick top ring land to help keep it together while detonating once in a while. maybe arp bolts in the rods if your going to rev it. if not reving it keep the valve springs on the lighter side, like z/28 spring. also upgrade your head to take chevy 1.90 valves. many companies make that size. they won't shroud as much as 1.94's do. use 1.6 for exhaust. the stamped steel rocker system will be fine with the lighter springs also. feel free to keep on asking. tom

also do not forget to use some type of timing control. this is a must while in boost. there is a fellow in idaho that really has a simple way to set up a turbo and knows how to do the timing control with a point type dist. maybe we can get him to chime in. tom

You can blow through almost any carb, the floats need to be plastic type
Holly makes the plastic type.Webber has them also.
Not brass because they collaspe. They did on my old Webbers.
The guys in Brazil like to blow through Webbers it seems ,or a single Webber.
Need to ask Douglas for some pics of there setups.
If you can build a turbo header it sould be made out of 321 stainless, but thats $$$$$ ,or get 304 stainless?
I thought tlowe (Tom) had a stock manifold modified to run a turbo? Maybe he can give a few tips on the mods needed for a stock manifold to work?
Hope this helps a little.

well, I think Tom has the special turbo manifold I was talking about. Its about 500 dollors though....I dunno, I'll need to think about it.


Tom, where did you get your 62-1 turbo from? I was looking on turbonetics site and they list a 62-1 turbo, then ones with a bigger shaft or something....do I need this or will a regular 62-1 work?

About the carb...I was thinking around a 650cfm? And holley will work?

For igniton, I was going to swap out to aftermarket and loose the points if I can...does MSD or the like make a kit?

I found a crane cam on summit.....

http://store.summitracing.com/partdetail...15&autoview=sku

but will it work with a turbo? I like the lower opperation range as I dont plan on reving the motor past 5000rpm.

What about bigger ratio rockers? Will small block chevy rockers work? What ratio is best?

Thanks

i was going to use one of the big truck 3 bolt manifolds to feed the turbo. then i ran into the one from inovative. it is expensive but solved so many issues in a hurry. mine was modified to accept a to4 turbo flange. my 62-1 is from turbonetics. they are all big shaft. mine is ball bearing stage V with .58 exhaust housing. the housing may be too small and aiding in my boost creep problem. i may need to go to a larger housing. according to calculations my engine is using around 700 cfm when in boost. 10-12 lbs. the rocker ratio is nearly the same as a bbchevy. the bbc rockers can be used. tom

so a .68 housing would have been better?

tlowe I.I.#1716
What does your torque converter stall to?

The 292 is almost a 5.0 & a .58 turbine housing is really small for that size engine.Sure, it will boost fast but probably over work the turbo from spinning so fast.You will loose a lot of top end power w/a small turbine housing.
If you have a torque converter that stalls to 1600-2000 a .58 housing will be OK , if you really do not want to make that much power on top or you just cruise around your vehicle & not worry about smoken some V-8 thingys.
Just my two cents. :-)

so what size housing would be best? In the 62-1 stage 5 turbo I only see them availible up to a .68 housing...that big enough?

What is your setup?
What is your goal?
Auto trans, stick?
There is a lot things to consider when turbocharging.

there is a .68 and i believe a .81 also. i am still ironing mine out. it does have plenty of boost. i'll wait to make a call on larger housing for now.

In a Turbonetics products catalog a 250-300 ci engine needs at least a .69 -.81 turbine housing.
I would think it is better to get the correct size now & do your tunning instead of tunning w/too small a turbine housing now & then go through the whole process all over again later.
Two cents?

my setup so far consists of a carb, I know Im going to run a carb, besides that everything is open. It will be a stick, most likely a 4 speed.

I know that I want to have a smaller housing so that my boost comes in sooner, I dont plan on reving the motor past 5000rpm, and it will most likely never see a professional track.

So far this is my setup...but everything can be changed...

292 engine with a complete rebuild
forged pistons
new crowler rods
crane cam
offy intake
innovated exhaust manifold
holley 750cfm 4barrel
bigger vavles and some porting in the head
62-1 turbonetics turbo stage 5 with a .68 housing
turbonetics rapor BOV
turbonetics evolution wastegate set at 14 psi
not sure what innercooler, but an air to air unit
HEI ignition

I think thats everything so far. Let me know what you guys think...Im very open to suggestions. Thanks

if you are not going to rev it high. then the money spent on the rods could be better spent elsewhere. on the manifold be sure to spec it for a to4 bolt pattern. one problem i ran into was they drilled one of the holes off to the side in the wrong spot. it was a little hard to correct. i think they did the same thing to a bunch of them. get a bigger intercooler with 2.5 openings. my tanks are 18 inches long with the fins being 6 " long. inlet and outlet on same side. this makes the plumbing easier. you will really like the big increase in output the turbo provides. i am going to try mine at a track next weekend. maybe i'll even take my brothers chevy II with a 383. we'll see. tom

What forged pistons are the best?

I would go w/JE's.
tlowe I.I.#1716 Make sure to video rec. your runs at the track. Goodluck!
Hank

do I buy pistons for a sb chevy or bb chevy? I dont see anything for the L6 292. And I want to the keep the 8:1 compression ratio...do I just get flat tops?

Order them through Sissell's Mike Kirby
http://www.sissellsautomotive.com/
He will tell what pistons to order.
SBC or BBC pistons will not work.
I suggest calling.(626) 331 2727

Here is a good turbo Ebay item # 200015647828
Here is another one Item number: 200017669741

this may be a pointless question...but about how much power would I be looking at with the motor layout I listed in the previous post? Im trying to size an innercooler and also I just realized the wastegate I have planed is only good to 400hp...

You could make 500 HP if you want to w/the stuff on your list.

yea, thats what I was hoping to hear. We'll see, I still need to learn the basic stuff....like attaching the plum work to the turbo itsself. If I know how everything needs to be I have the skills and tools to fab everything up, but the problem is in the details. Like the size line needed to run the oil pressure line and return line, and the water lines, and running and connecting the tubing to the innercooler... So I got some more reading to do I guess. If anyone else has insight on the whole thing post up, other than that I guess I will let this thread die for now...my only real last thing is figuring out about making a carb take boost, not sure I understand if I bolt on a holley with plastic floats is that it, or do I need to do something weird....

As long as the throttle shafts are not too loose you should not loose too much boost pressure.
You can purchase an enclosure for a carb that encloses the whole carb.
Paxton had them. I think Vortec has them & other company's.
With the carb completly enclosed you do not need to worry about the throttle shafts leaking & other leaks.
You still need the plastic floats though.
http://www.vortechsuperchargers.com/products/yourcar/univ_carb_encl.html
Paxton Universal Carburetor Enclosure without Fuel Lines (satin)
All
$650
http://www.superchargersonline.com/product_listing_2M.asp?Cat2=accessories_carbenclosure
http://www.superchargersonline.com/product_detail.asp?PartNumber=V8M205-012

quote"I found a crane cam on summit.....

http://store.summitracing.com/partdetail...15&autoview=sku"
I do not like the duration higher on the exhaust side.
If it was the other way around ,more duration on the intake, that would be better.

I started realizing that...that I need more intake than exhaust, I will keep looking...

about the carb box, I'll pass. I'm just going to keep looking for carbs that can take boost. I thought about using some short of simple efi like a tbi setup off of a 454ss type truck. Im faily sure those can take boost and they look much like a carb and don't seem hard at all to tune. Having a newer chevy truck tho, I know that tbi flow about as good as a coffee straw so Im still looking...

Cajundragger!

I think, in your case, the best set up is a Weber 40 or 44 with plastic floatings.
And if you got more boost, just add some additional fuel injectors.
We have some guys here in Brazil producing almost 900 hp with this configuration on the 250 (Weber 44 + 3x160lbs fuel injectors).

Tom is right.
If you will rev no more than 5.000 rpm and 14 psi of boost, I think you don´t have to spend your money with forged pistons and forged rods. Just put some good bolts in your stock rods and it will work really fine.
But if you have in mind to run like 18 or 20 psi, a set of some Sportsmans forged rods will save you to blow up everything.
Like Hank... Just my Two cents!!

is that weber fuel injection or what? excuse my ignorance but I hvae no clue about webers and that short of thing. Are all webers a sealed carb? They make the intakes that mount 3 2 barrels....this would work great if I can get a three of the correct carbs. I know Running the tubing to them would be a bit of a challange but it would be worth it I think...And I dont know how I make the linkage work either, but I'll do some research. I think Im doing pretty good though information wise condering Im 17 and just started reading up on this 6's two weeks ago or so, I have everyone on this site to thank, so thanks guys.