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6.5 to vm638

Mike K3500 said:
Sounds like a whole bunch of go-go juice... now, to go about getting that kinda fuel from a DB4
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Well, if i had a db4 here, I could dig in and make something happen! Not sure what you'd do with 200cc of fuel on a 6.5! Make carnage I guess!

This is why I like my ve pumps. Just too easy to get alot of fuel, and timing from. Not to mention, they remain as reliable as stock when fully modded.
 
Is there any 8 cylinder VE pumps that could be migrated to a 6.5 platform... ??

Thing I do have in question is.. how many people have stuffed a lot of fuel / boost to a GEP foundation or P400... ???
 
Mike K3500 said:
Is there any 8 cylinder VE pumps that could be migrated to a 6.5 platform... ??

Thing I do have in question is.. how many people have stuffed a lot of fuel / boost to a GEP foundation or P400... ???
Click to expand...

Unfortunately, there are no 8cyl ve pumps. In fact, on the 6cyl, we run into plunger fill time issues.

I too wonder how many people have pushed the better 6.5 blocks. If they held up, would be an absolutely deadly engine!
 
Sorry, not trying to intentionally steer off course here.. I'm just very inquisitive and like to learn a lot. Sometimes it's just hard to find any good info on certain diesels, injection pumps, cool swaps... etc.

I kinda like the individual head idear on the 638, but seems as though it would have more cooling surface area and capacity if it were one solid head..
 
Don't feel bad Mike. It's ok to be curious!

I too thot that 1 cylinder head would have been better. But, think about how warped and out of shape it would get. The individual heads can walk around on their own as they heat up and cool down at different rates that the block.
I have acutally had 1 head gasket literally wear out from the heads moving so much. It is a multi-layer steel gasket...
 
Now.. would studs do any justice in that situation. ? or do you plan on using them.. ? and would it be possible to "speed up" the water pump and have it do anything more for the cooling of the heads to prevent cracking .. ??

On a side note.. I did watch the season of Amish Mafia.. LOL .. and that takes place in Lancaster, are you familiar with any of that silliness.. ??
 
It has 14mm bolts for the clamping force around the cylinder, and 12mm on the outer bolts. No real sealing issues, so no plans to use studs. I plan to use a high flow thermostat this time. It appears alot of my cooling issues were due to incorrect thermostat.

Never watched amish mafia. Have no clue about it. Not much of a tv watcher...
 
Is that the inherent problem to the head cracking is lack of cooling capacity, improper thermostat, drive pressures.. ??.. OR, is it just the nature of the beast by design of these engines.. ??

I'm very interested in these, maybe a future project after the current one is done. I have nothing against the tried and true cummins swaps, but I like the idea of trying something not so mainstream or the norm. I really wish there were some I-6 Cats that would be similar in size to the VM638...

I also can't wait to hear yours run and see some "live action" vids of it zooming down the road..

Mike
 
I really just wanna see pictures of it fit into the truck/engine bay...and the adapters that make it work properly...

While it's true that if I ever owned a 6.5 and decided a conversion was a better option, I would use the Cummins like this one

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I can't remember anymore, but I think it may be twinned...
 
That's a very clean install.

I am just tired of people saying drop the 6.5 for a cummins. I want to do something different just to stick to em so to speak.

Maybe an Eaton 10 speed behind the little bugger since it has an sae 2 bell housing. Just assuming since it could have a 545 ally.
 
I owned a 94' 6.5 for two years...before I could find internet help sites for it... but it was under warranty and around 60k mi. it gave me lots of problems...dealer replaced a ton of things including authorizing a brand new stanadyne injection pump...when all it probably needed was a remote PMD...it threw the SES code on the way down the highway from the dealer...I made a u turn and had the dealer reset the code and babied it straight to a dodge dealer and bought a cummins...I kept that truck until the new Crew Cab design with the duramax came out and came back to GM where my loyalty lies...Had there been or had I known of these sites or or how to fix them, I may still have that truck...which would be a shame because based on my memory of my 6.5, the 800 platform and duramax is just so much better...with the price of LLY's now, I can't see why someone would spend a lot of money on keeping/improving a 6.5...

that being said, I have had my eye on a 98 sub with a 6.5(around the corner) just for traveling...the wifes 04 tahoe only gets around 15mpg...
 
The price of injectors cp3 and building the Allison builds a really nice 6.5L that is cheap to maintain (once it's set up)

made this decision when my Dmax started slipping the tranny and had some fuel pressure issues and my 93 K3500 needed a few parts.

Rolled the Dmax to light duty service until more funds show up and put the 93 to heavy hauler.
 
yeah, but you have an 06' :LBZ...way more power stock...bullet proof... and a much better puller to boot...had you left that truck stock, it would still outperform any 6.5 you could possibly build and it would still be in service...you can't blame the dmax for what you did...a transgo junior from the get go before adding power would probably prevented this also...cost wise a stock LLY or LBZ is cheaper than modding a 6.5 to try to do the same as a stock LLY...injectors on an LLY or LBZ are really a non issue and afaic CP3 failures are rare too...
 
Rail pressure point to a couple injectors with high return rates. Truck rarely left level 2 towing 20hp iirc. Yes it pulls good but temps go out the roof in a hurry on mine. I know there are tranny cooler upgrades and what not. I plan to put together a solid truck out of it but the 93 is cheaper and more what I need at the moment. Efi Live will let me get better use out of it for the time being.
 
Mike K3500 said:
Is that the inherent problem to the head cracking is lack of cooling capacity, improper thermostat, drive pressures.. ??.. OR, is it just the nature of the beast by design of these engines.. ??

I'm very interested in these, maybe a future project after the current one is done. I have nothing against the tried and true cummins swaps, but I like the idea of trying something not so mainstream or the norm. I really wish there were some I-6 Cats that would be similar in size to the VM638...

I also can't wait to hear yours run and see some "live action" vids of it zooming down the road..

Mike
Click to expand...

I thot I was smart back in the day, and got a new thermostat for it. Not realising it was incorrect, and all the time I ran it, water temps were top concern. Now, knowing better, I will be curing that issue, and hopefully steer clear of cracked heads.
it does seem the head cracking was a weakness of this engine. Heads are always in stock at the dealer. Not exactly a great sign.
 
tanman_2006 said:
I am just tired of people saying drop the 6.5 for a cummins. I want to do something different just to stick to em so to speak.

Maybe an Eaton 10 speed behind the little bugger since it has an sae 2 bell housing. Just assuming since it could have a 545 ally.
Click to expand...

Exactly! I have a 4bt here that I built purposely for this truck. But honestly, what is the fun in that? Just another chevy with a cummins.

Not sure what the other bellhousing is. Sae1 or sae2. Not sure. But this thing with a few extra gears would be a blast to drive!! Smallcase 10speed would be nutz!
 
I was thinking 4bt until I saw this. It will go into a truck w/ service bed so no heavy loads but will be a heavy truck not exactly fast but I want good mpg and steady power, if that turns out good then I might build another if time/funds permit.
 
tanman_2006 said:
I was thinking 4bt until I saw this. It will go into a truck w/ service bed so no heavy loads but will be a heavy truck not exactly fast but I want good mpg and steady power, if that turns out good then I might build another if time/funds permit.
Click to expand...

If you decide to use one of these engines, feel free to give me a yell. I'll gladly help ya where I can!
 
Mike K3500 said:
Is that the inherent problem to the head cracking is lack of cooling capacity, improper thermostat, drive pressures.. ??.. OR, is it just the nature of the beast by design of these engines.. ??

I'm very interested in these, maybe a future project after the current one is done. I have nothing against the tried and true cummins swaps, but I like the idea of trying something not so mainstream or the norm. I really wish there were some I-6 Cats that would be similar in size to the VM638...

I also can't wait to hear yours run and see some "live action" vids of it zooming down the road..

Mike
Click to expand...

All of the VM engines with modular heads had this head cracking issue when I looked into them. It was just the nature of the beast as one would say. I believe it had to do with how the coolant circulated(or lack there of) from the individual cylinder heads, and the loss of material between them to absorb and deal with heat. Another one of them great designs in theory, but in reality didn't pan out.
 
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