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1998 suburban 6.5 boost question

C

COAL BURNER

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moonstone ontatio
I'm hoping some one might be able to help me out.

I recently bought a 1998 suburban with what I was told had a marine 6.5 engine installed in it.
How can I tell a marine engine from a regular eng?????
The only thing I can tell that is different from every other 6.5 that Ive seen is that the turbo does not have a waste gate and having removed the manifolds to replace leaking exh. manifold gaskets found no provision to bleed off any exhaust as with a waste gate also the turbo outlet (air side) is smaller than the intake pipe (the top of the intake) mine has a stepped rubber hose as opposed to a straight hose.
Also after installing a boost gauge (and 4 inch straight pipe exhaust) my boost is 18 psi and holds steady.
Are there any vin #s to look for????
any help would be appreciated.

thanks
 
They probably just meant it has marine injectors and the intake that peninsular makes for the engines they put in boats. No real difference in engines. A marine engine would have lot of accessory differences as the real main difference, and possible modified for salt water in which case you may not want it for a truck.
 
Thanks for all the input
I will post some pictures within the next day or two
I remember the model gm8 turbo by Borg Warner when I ran the model and serial from the tag (thats when I did the exhaust manifold gaskets) but It has a smaller diameter outlet on the air side. (and 18 psi of boost!!!!!!)
Any way picts to come.
 
Yes, like mentioned it may have been lowered to 18:1 CR like marine engines and use "marine" spec injetors which use a larger nozzle and higher pop pressure, but otherwise the engines are essentially the same, and it has the normal truck intake. The builder at least knew some things, converting battery connections, moving the PMD out of the engine valley (although by the fender is still probably not the best). Remote mounted the fuel filter with easy access. Not sure why they cust hole out of the air filter box, does it have hood louvres or something?
 
A GM8 turbo's compressor housing outlet would match the size of the intake, but yours does not, it adapts from like 2" to 2.5"

A GM8 would also have a heat shield over the turbine housing, and although it can be removed there would be flat spots on the housing where the screws would go in to hold the shield on.

So I dont think it is a GM8, where does it say GM8 on it?
 
thanks A K and Buddy for your help.
I had the turbo off once and ran the serial #, apparently its a borg warner gm8 (but I agree its not like any other gm8) the exhaust housing and air housing seems larger than stock.
As for the drilled air box... I did that my self and really noticed a dif. You can feel your hand being sucked in a little when you cover up the holes.
At any rate marine or not this engine really moves out , and Im very happy with its performance(but not the fuel milage!!!!)

Thanks again guys.
 
COAL BURNER said:
As for the drilled air box... I did that my self and really noticed a dif. You can feel your hand being sucked in a little when you cover up the holes.
Click to expand...

Hot underhood air vs cooler fender air. Derate your engine power and economy by giving it hot air vs the colder denser air.
Look for and remove the restrictive inner fender snorkel if it has one. This should give it the air it wants. Then replace the hot air intake holes...
 
Hate to tell you this, but all you really did was cut up a fairly hard to come by k47 airbox and reduce it's effectiveness.

The turbine housing and turn down pipe all say "Holset" to me, but I can't really see any other distinguishing features for clues as to it's identity.

My 98 has a GM8 and that looks nothing like it and I mean NOTHING. I would say it's not anything GM ever put on a 6.5, but rather some other add on by the PO. The GM8 turbo's were made by IHI, not Borg Warner. I've seen guys claiming they're BW, but have only ever seen documentation for IHI...

From the looks of things, I'd say it's doubtful it's a "marine engine, but rather the stock block with perhaps replacement marine injectors at best. Benefits of marine injectors on an otherwise stock truck is debatable. While there may be some benefit, PCM programming and a bit of work in the Inj pump are required to make full use of them.

Also, for some reason that engine bay looks familiar. As in, I've seen it somewhere before. I can't put my finger on it though....

Good news is that it looks like you've got a "full blown" VIN F truck there. Little bit more aggressive PCM programming, no EGR, K47 RPO box, etc.

Just epoxy those cut outs back into the airbox......;)
 
You know, the more I look at that turbo, the more I think it's the turbo that's offered by Peninsular.

The turbine housing and exhaust turn down look pretty much bang on.

Maybe you do have an 18:1 engine there.....you can see a similiar photo on the peninsular site here:

http://www.peninsulardiesel.com/WP-PENTEST/?page_id=9

Or it may just be a replacement peninsular turbo.

Only way to know for sure is to find out the compression on the engine and/or flow the nozzles...
 
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