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Remote mount turbo thread.-progress and questions!

Turbine Doc said:
CR is same piston coatings and piston top design IIRC come into play as well, 6.2 pistons aren't coated for higher temps you see with turbo @ higher pressures,
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Since when is the compression the same? Everything posted on here says 6.2 N/A's have higher compression than 6.5's, hence the main reason we can't run high boost. Why are all the 6.2 guys looking for old discontinued lower compression pistons, or using a thicker head gasket or possibly milling the piston to lower the compression?

Edit, found this, compression on a 6.2 is 21.5:1 and "Compression: GM Early 6.5 21.3:1, GM Late 20.3:1, AMG/GEP Marine 18:1"

Turbine Doc said:
Turbo van you might want to get up with Bill Heath hes dabbled in racing 6.2 on the strip and may have some good advise to share with you.
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I might do that, I have to order a TM from him for a customer.
 
Everything posted ??? only guys with 18:1 in 6.5 land are guys that lowered CR for high boost turbos HX-35, all GM built 6.5s are in 20:1 range in factory trim.

I know of a number of 6.2 guys looking for 19:1 pistons, me also but alas no longer to be had, I was going to build a 19:1, 6.35 turbo engine, scarcity of 19:1 pistons I opted for a Chinese copy of the AMG 6.5 block, and am now running a lower stress ATT high cfm turbo than what GM turbo was running at staying with the 20:1 CR I've been around 18:1s I don't like them as much as I like the stock CR ones.
 
Turbine Doc said:
Everything posted ??? only guys with 18:1 in 6.5 land are guys that lowered CR for high boost turbos HX-35, all GM built 6.5s are in 20:1 range in factory trim.

I know of a number of 6.2 guys looking for 19:1 pistons, me also but alas no longer to be had, I was going to build a 19:1, 6.35 turbo engine, scarcity of 19:1 pistons I opted for a Chinese copy of the AMG 6.5 block, and am now running a lower stress ATT high cfm turbo than what GM turbo was running at staying with the 20:1 CR I've been around 18:1s I don't like them as much as I like the stock CR ones.
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I edited my post, I didn't realize that the 6.5 was high compression too,See now Thx :thumbsup: I guess I got mixed up with the 6.2 guys looking for Marine pistons.

So barring the piston top issue, why can't we run more than 10 psi, the HY35 should flow more air and be cooler than a stock GM turbo. As long as EGT's are kept in check, what's the problem?

Not sure if you can post Ebay links but here are some 6.5 Mahle Marine pistons- Hot Link to ebay store Falcon Global pulled while normally not an issue to generic link to ebay we have vendors that could get those (I Think) but Falcon as a business chooses to spend advertising $$$ with ebay vs here so no need to advert for free here it's a case by case judgment had this been an invivdual vs business it probably would have been allowed, when in doubt PM a mod
 
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turbovanman said:
So barring the piston top issue, why can't we run more than 10 psi, the HY35 should flow more air and be cooler than a stock GM turbo. As long as EGT's are kept in check, what's the problem?
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Can you run more than 10 I'd say yes, would I no, here's why 6.5 head is beefier than the 6.2 I think (I have limited 6.2 experience), and my tore down 6.2 is 1500 miles away for me to confirm it.

But the chamber area created by the 6.5 head is bigger thicker gasket on a 6.2 could add some additional margin, but I also I think improved cooling H2O flow ability with the 6.5 head, if it were possible to just up-boost a 6.2 why would GM have just not added the GM-X turbo and be done with it.

Diesel Depot builds and Bill Heath runs the 6.35 at Bonneville, so there is some extra oomph in the 6.5 head design allows for the management of the higher boost, so it plus the piston changes combined are required.

There is only X volume in a cylinder until the dynamic forces in compression adding heat/pressure where you either have to back off (limit boost) or redesign piston/heads to work within the elevated boost levels.

When Bill was drag racing the 6.2 he actually lowered it's CR to 14.5 :1 if I recall, to allow for boost 40-60 psi ??? I don't think he used 6.5 heads in that one; he says it was a DOG until it was warmed up, sometimes taking as much as 15 minutes to get it started and able to idle, but it was capable of front wheels off the ground launches at the track when the tree went green.

There you have fully expended what little I think I know about the 6.2 :D
 
Turbine Doc said:
Can you run more than 10 I'd say yes, would I no, here's why 6.5 head is beefier than the 6.2 I think (I have limited 6.2 experience), and my tore down 6.2 is 1500 miles away for me to confirm it.

But the chamber area created by the 6.5 head is bigger thicker gasket on a 6.2 could add some additional margin, but I also I think improved cooling H2O flow ability with the 6.5 head, if it were possible to just up-boost a 6.2 why would GM have just not added the GM-X turbo and be done with it.

Diesel Depot builds and Bill Heath runs the 6.35 at Bonneville, so there is some extra oomph in the 6.5 head design allows for the management of the higher boost, so it plus the piston changes combined are required.

There is only X volume in a cylinder until the dynamic forces in compression adding heat/pressure where you either have to back off (limit boost) or redesign piston/heads to work within the elevated boost levels.

When Bill was drag racing the 6.2 he actually lowered it's CR to 14.5 :1 if I recall, to allow for boost 40-60 psi ??? I don't think he used 6.5 heads in that one; he says it was a DOG until it was warmed up, sometimes taking as much as 15 minutes to get it started and able to idle, but it was capable of front wheels off the ground launches at the track when the tree went green.

There you have fully expended what little I think I know about the 6.2 :D
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Aren't the heads almost identical, barring precup sizes? And 6.5's have overheating issues, we don't.

Not sure why the pistons are an issue, it seems we have a thicker crown which is good for heat resistance, reminds of my Caravan and the difference's in pistons etc.

Not sure why GM didn't turbo a 6.2, maybe they figured it had a bad rap so increase the displacement and then turbo it, win win for them and more power for us.

Fully understand about boosting, compression ratio's etc, see sig, ):h

14.5 sounds right if your pushing 40-50 psi thru, the new engines are designed for boost so lowering it that much isn't needed.
 
the 88-91 head are identical. the IIRC the 84-87 heads have the different angle injectors and the the pre-84 have the course thread injectors.
 
turbovanman said:
Aren't the heads almost identical, barring precup sizes? And 6.5's have overheating issues, we don't.

.
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Now I done tole you, I was gettin thin on my 6.2 knowledge :D 6.2s don't OH no turbo to make extra heat,

6.5 heads are close to the 6.2 but not exact, I don't mean to speak in general terms but I really don't know the exact differences between the 2, it took GM several iterations of 6.5 to get it almost right in area of cooling changing pumps stats etc.

Rite about the time GM had it nearly resolved the D-max started and for a while the 6.5 work ceased. Enter a bunch of diehard or just to dumb to know when to call it quit folks and we have some fairly robust 6.5s out there, which when set properly one can have thousands of run cool miles out of their 6.5,
 
Turbine Doc said:
Now I done tole you, I was gettin thin on my 6.2 knowledge :D 6.2s don't OH no turbo to make extra heat,

6.5 heads are close to the 6.2 but not exact, I don't mean to speak in general terms but I really don't know the exact differences between the 2, it took GM several iterations of 6.5 to get it almost right in area of cooling changing pumps stats etc.

Rite about the time GM had it nearly resolved the D-max started and for a while the 6.5 work ceased. Enter a bunch of diehard or just to dumb to know when to call it quit folks and we have some fairly robust 6.5s out there, which when set properly one can have thousands of run cool miles out of their 6.5,
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Heheehee, ):h

I really don't think we are dumb. Lets see, $40+ thousand for a new truck van or pennies for an older truck/van with lots of money left over for mods.

My van was free with a knock, fixed that, the mods in my sig, so I'll have maybe $3000 into it over 4 years and that's mostly the new trans. :thumbsup:
 
Yeah but if we let everybody in on our lunacy/secret the pool of "used but good" parts dwindles too fast, or gets expensive, let the "haters" keep us supplied with viable organ donors :Justwait2:
 
Turbine Doc said:
Yeah but if we let everybody in on our lunacy/secret the pool of "used but good" parts dwindles too fast, or gets expensive, let the "haters" keep us supplied with viable organ donors :Justwait2:
Click to expand...

Same thing with our turbo dodges, we don't want too many folk figuring it out too, ):h
 
cool beans

When you get around to IC it, I'd go with air to water. Easy to mount anywhere, many kits available on the web, maybe even from our vendors (plug) ;)
It's what is in my plan for the 6 in my '67. I'm to build a draw through for my 4bbl Holley (currently mounted on an Offy intake). I used to smoke the 5.0 'stangs, but it's been rusting lately. :(
 
I seriously doubt I'll put an IC in, I am not going all out.

I will probably drop the engine in the winter and put studs in and better head gaskets.
 
Sorry guys, the project is officially dead. I got a 95 F250 Supercab 4x4 Powerstroke in mint shape, literally given to me with injector and front end issues so the van will be sadly, up for sale. The truck just suits my needs better as I want to a camper so I can still tow my enclosed trailer.
 
Woody35 said:
have fun with the heui setup
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Is that sarcasm?

Its a pretty simple, bulletproof system after a few upgrades. Do I want to move on, not really but when the truck is literally given to you and it suits your needs, why not? :thumbsup:

I would rather have a GM 6.5 but no one has given me one so to speak, :(
 
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