How about a Twin Turbo 6.5 in a 73-74 Blazer?

[Uncle Wally]

Dr. Lee,

I recently came across a 73 Blazer that is minus the engine, trans and t-case. It got me thinking! (obviously with the title to this)

Have you heard of anyone doing something like this? The exhaust would have to be hand fabricated. Use two smaller turbos to get boost up there quick right out of the hole. Run an old SM465 manual and a 205 t-case. Has anyone put a Gear Vendor between the trans and t-case?

Just some brain storming ideas. I thought it was a neat idea. Especially with the full convertible top!

Waldo

[CleviteKid]

You should do it !!

One of our European members has a twin-turbo truck running. Peninsular Engines has shown a twin turbo on their web page, and on a stand at Rendezvous III.

With no A/C, it shouldn't be impossible to place the driver-side turbo and route the exhaust down and back.

If you want a real screamer, you will need to feed the output of both compressors to an intercooler before it enters the intake manifold.

We wanna see pictures, so get to work !!

Dr. Lee

[cowboy832]

I am actually considering a similar setup on my 6.2, but the project will take me a long time since I will be forced to take about a year off while I am in Iraq.

[Uncle Wally]

Dr. Lee - I got to thinking - I'm not sure a gear vendor is a good idear. Too short of a driveshaft.

OK - here's a big engineering question. In order to get everything just right, some calc's should be made to make sure that there is enough velocity in the exhaust gases. Where would I get some of the formulas used for this. Any thumbrules? I know it's a little out of the mechanical engineering/metalurgy realm.

Waldo

[britannic]

Originally posted by Uncle Wally:
Dr. Lee - I got to thinking - I'm not sure a gear vendor is a good idear. Too short of a driveshaft.

OK - here's a big engineering question. In order to get everything just right, some calc's should be made to make sure that there is enough velocity in the exhaust gases. Where would I get some of the formulas used for this. Any thumbrules? I know it's a little out of the mechanical engineering/metalurgy realm.

Waldo

Most of what you need is right here:

[www.hotrod.com] Turbos: Science and Selection

[Peter J. Bierman]

What I did to calculate the turbo and intercooler size is:

Match the theoretical airflow of your engine with that of the donor engine.

rpm X displacement = theoretical airflow

for twin turbo setup you have to take the airflow off one cylinder bank being 3.1 L X 3600 RPM and compare with the donor engine.

It's not real science but it's close enough.

You HAVE to lower compression and have intercoolers to keep the engine alive, other wise the twin turbo setup is useless.

What I learned is that with so much air there is not enough fuel, so a bigger (biggest) IP is needed.
Got one waiting to be mounted as soon as I figure out what injector nozzles to use.

Yes I am that mentioned Euro member.

Goodluck Peter

[Uncle Wally]

I spent some time reading the turbo articles from Hot Rod Mag. It gave some good advice for gasoline engines, but there wasn't much that related to diesels.

I dropped a note to the folks at turbonetics and am anxiously awaiting. I looked at a few compressor maps and think I found what I would like to try.

Issues:

There's not enough room in the 73+ engine bay.

I stopped and looked at someones 70 truck with a measuring tape, and I think it would fit quite nicely in that compartment. Twins take up a lot more space that I orignally thought. Probably more than I think still, but I have a good picture. Needless to say, I'm not familiar with the 73+ engine compartment enough to know where all the diesel stuff goes. Where is the glow plug relay? Firewall?

Stock isn't going to handle 30 psi, so a GEP block would be in order.

Has anyone done an o-ring head gasket on these engines? They're common for the guys runnin big boost on supercharged gas stuff. But I haven't heard of it in the diesel world. Any advice?

Thanks,
Waldo

[britannic]

How much power do you intend to make? 30psi boost is a huge amount of air (if properly cooled down), even the DMax only uses around 23-26psi in stock form for 300HP.

The Peninsular 6.5LTD doesn't use much more than 10-12psi for 300HP. You'll need some serious cooling mods before you can inject enough fuel to match 30psi of boost.

The 6.5LTD can handle plenty of boost, it's heat rejection that becomes the problem. You won't need to o-ring the engine, but new gaskets and head bolts would be prudent.

[CleviteKid]

Hey Waldo, if you wanna do it, it can be done. Here is a photo of Peter Bierman's installation (courtesy of www.oliverdiesel.com):


Peter has fabbed his own exhaust to position the twin turbos up over the rocker arm covers. Notice he has even included twin feeds and twin returns from his intercooler(s).

You can't let little things like glow plug relays worry you - just put them wherever they fit and hook 'em up with 8 gauge wire.

Don't give up Waldo - we know you can do it, and we will give you all the free advice you need .

Dr. Lee

[Uncle Wally]

Thanks Britannic. I suppose the limiting factor in heat rejection is the capabilty of the engine/waterpump etc to flow. I would think you could get things quite cool with a huge aluminum radiator.

Dr.Lee - the only reason I asked that question about the relay is becuase I like thing to look like they came from the factory that way. In other words, I don't want to add a bunch of holes to the firewall of a classic. That's all. I suppose I should have asked what else needed to be mounted in the engine bay, but I figured the glow relay would be the only thing for a mechanically injected diesel. Planning would get it figured out!

Now if I could just find a reasonable truck to start with! (I always did want a 69-72 Blazer)

I'll keep this going as things progress!

Waldo

[Uncle Wally]

A 72' Blazer was just delivered to the driveway this weekend. She's rough. Very rough. But it's a starting point! If I can get the Digital Camera to download, I might have a few pics that I can post.

Waldo