[Tom Vaught]

Originally Posted by Jay S

You all have me wondering if I have a diesel turbo or two that would work ok for one our boost projects. We have a collection of them. One was off a 3512 cat gen set, two turbos for 3500+ or so cid engine. HUGE! Have a Mack that had a new turbo and shot a rod out the side, Cummins 855 turbos, cat 3406, 3208t, some newer 11.1 and 12.7 Detroit’s. Had not considered using any of those for a gas build. Figured most would be to cumbersome. We used a TO4 off a John Deere tractor on our street turbo build years ago. Seemed like the seals were touchy was my only complaint turbo wise on our old turbo engine. I will have to do some research, might have a tv8101. Jay

Most times if you have Turbo Seal issues you have a poor turbo drain design or the Crankcase is not vented properly.

Tom V.

[Jay S]

Thanks Tom. The problems we had with seals absolutely acted like drain problems. I think we sent the drain into a place on the oil pan that had too much windage. We still have that system we built. At first we ran a Schwitzer draw through set up. Thought it was an issue with the turbo so we had it rebuilt, changed nothing. Ran it for about a year, then we changed it over to a blow through with the TO4. Blow through seemed to help but still had an issue with oil occasionally. It was in a 72 plymouth satellite/road runner with a 318. It was a blast to drive, had plenty of little gremlins in the system though.

I think the 3208t cats run a TO6. I have several of the TO6’s. They are 636 cid v8 go up to 425hp at 2600 RPM in marine apps. Always thought the TO6 with some trim changes looked like it was about the right size for a moderate 400-450 cube street/strip build for a single turbo.

The 8V92TA Detroit was fun to drive in a semi with no trailer. It had a bunch of lag, then all of a sudden at about 1800 rpm you could hear to turbo come in and it went from feel like a big rig, to a good running pickup truck. Put you back in the seat. lol, it is hard to imagine a gas engine spooling that same turbo up. Sounds cool! Jay

[Boostedbird]

Originally Posted by Jay S

Thanks Tom. The problems we had with seals absolutely acted like drain problems. I think we sent the drain into a place on the oil pan that had too much windage. We still have that system we built. At first we ran a Schwitzer draw through set up. Thought it was an issue with the turbo so we had it rebuilt, changed nothing. Ran it for about a year, then we changed it over to a blow through with the TO4. Blow through seemed to help but still had an issue with oil occasionally. It was in a 72 plymouth satellite/road runner with a 318. It was a blast to drive, had plenty of little gremlins in the system though.

I think the 3208t cats run a TO6. I have several of the TO6’s. They are 636 cid v8 go up to 425hp at 2600 RPM in marine apps. Always thought the TO6 with some trim changes looked like it was about the right size for a moderate 400-450 cube street/strip build for a single turbo.

The 8V92TA Detroit was fun to drive in a semi with no trailer. It had a bunch of lag, then all of a sudden at about 1800 rpm you could hear to turbo come in and it went from feel like a big rig, to a good running pickup truck. Put you back in the seat. lol, it is hard to imagine a gas engine spooling that same turbo up. Sounds cool! Jay

This was 3 years ago. Started pull at 2,500rpm.

https://youtu.be/lY_tGndaJ-M

https://youtu.be/SZbAtrtjVho

Second video is part throttle. Goes into boost pretty easy.

[Jay S]

Thanks for the video link. Your right, lag was not bad at all. Looked wicked! Jay

[azbirds]

Good thread. I'm new to the turbos so this got my attention. I got two turbos that had been mounted but never run. What would these be best suited for engine size wise.

[Tom Vaught]

Info from the turbo tags would help a bunch vs just a couple of photos.
Then we could go to a Turbo map for the turbo and see what the mass air flow in
lbs/min is and the Pressure Ratio for the different efficiency islands.

Here is a sample Turbo map for a Borg Warner Turbo.

Some things to know: On the left side of the "map" you see Pressure Ratio.
a 2.0 pressure ratio is about 15 psi of boost pressure.
a 3.0 pressure ratio is about 30 psi of boost pressure.

On the bottom of the map is the Lbs per Minute of Mass Air Flow.
1 lb/min will make about 10 engine horsepower.
if you have 40 lbs per minute you have about 400 HP of air mass flowing thru the turbo.

At 60 lbs per minute (60 on the lower axis) and move upward, the turbo efficiency point is .76 or 76% efficient which is very good.
That is the smallest circle shown on the turbo map. That island is labeled .76 on the map.
That means the example BW turbo could make 600 HP per turbo or 1200 horsepower on a engine.

You need a map for the turbos you found azbirds.

Tom V.

There is a couple of other things to look at on the 'map'
On the left side of the largest island is a heavy blue line. That line is the Compressure Surge Line.
That line is also not a perfect line. You can get compressor surge even a couple of lines to the right (.68 line)
on the map (going towards the smallest island with the highest efficiency.
The point of this is IF you do not have enough engine mass flow at low speeds then the turbo compressor will SURGE.
Surge is not a good thing for a streert vehicle. Race, (may not be an issue). So you do not bolt a LARGE Turbo on a
350 cid engine and expect it to be happy at low engine speeds. So all of the info on the map tells the Turbo people something.

[azbirds]

Thanks! I'll look at it for a tag tomorrow and post it.

[azbirds]

OK, it has a Perkins tag 2674A237 and I found this info.

[Tom Vaught]

Does it look similar to this turbo?

https://powerdrivendiesel.com/produc...-96mm-turbine/

Tom V.

[azbirds]

It does look just like that. I don't have my digital calipers at home to measure so I took the rear cam plug and put it up to the wheel and it looks almost perfect. Cam plug says 2 1/16.

[Tom Vaught]

Can you believe that, An old Ford Turbo Guy actually got something close to being right on a Turbo Forum. LOL!

Those are really good turbos by the way. Not "Ceramic Ball Bearing" Turbos but really good Journal Bearing Turbos.

Tom V.

[azbirds]

Thanks Tom!! I knew answers could be found here. I would say I got the better end of that deal because I can get an engine stand for $100.So I should only need one turbo instead of two like I had thought.