phalanxx

hey guys! i have an 71 cj6 that came with the buick v6. so its all BOP config. i have an sm420 granny trans converted to BOP.
i have a buick grand national turbo SFI that i am about to put in it, then i ran across a guy selling a 350 olds diesel. ive been wanting to diesel convert my jeep for a long time but everyone has the cummings or whatever. i want something different. and, if the 350 diesel is BOP, i wont have to buy a new adapter.
i have several questions..
is the 350 olds diesel BOP bell housing?
ive seen guys stroke em to 4.1" using the smaller main 425 cranks and whatnot for gas conversions, can this be done to a diesel?
what mods would have to be made for the fuel line to handle that? i plan on putting an electric pump at the tank.
i also want to stick a turbo on it. i read that the cummins has 18 or so compression and this is 22.5. if i had a good crank and rods, forged pistons, addressed all the weak bolts with ARP studs and a girdle, would it be able to handle say 10 lbs of boost?

this is just a starting point. if any of you want to chime in and give me a direction and what might be needed to do said conversion (or if it would be worth it) i would be grateful.
i would even send the engine to a builder to do these mods or come along with it with a case of your flavor.

thanx
rowdy j

oldcutlass

Welcome to the site, I moved your thread to the engine forum for discussion. I'm not familiar enough with the Olds diesel to comment other than the bell housing is BOP.

phalanxx

SWEET!!! BOP is a step in the right direction.

jcdynamic88

yes on the bellhousing(is sm420 a manual?) and at the very least it needs to be the DX block .nothing special about fuel delivery on the olds diesel,they had regular mechanical pumps feeding the mechanical injector pump.i doubt the crank is drilled for pilot bearing tho.fwiw my experience with the olds 5.7 diesel is with removing them and replacing with gas engines although i have owned and enjoyed several diesel powered olds cars over the years

olds 307 and 403

Bottom end isn't the issue. Getting 4 bolts per cylinder to seal is the issue, think Ford/Navistar 6L. At minimum ARP studs and Cometic head gaskets, with an O ringed block and Copper head gaskets being the best. I would run thick as gaskets needed to lower the compression into that same range.

Olds64

x2

You would definitely need head studs. I've read about 6.0L owners having the block machined for a fire ring when installing head studs. I don't know if this would work with an Olds diesel. Don't you need special head gaskets to do this mod?

Don't change the bottom end. As you said, folks stroke the motor with a 425 crank. However, that is for gas conversion.

If you put a turbo on it 10 psi of boost is the most I would shoot for. The Olds 350 diesel like the 6.9L and 7.3L International IDI engines weren't built for a turbo so you have to be careful. It's not as easy as scavenging a turbo from a 7.3L Powerstroke or a 6BT Cummins and bolting it on your Olds 350 diesel.

One of the first mods I would do besides headstuds is installing a water separator between your electric fuel pump and your injection pump. Water will destroy a diesel engine pretty fast since it's incompressible.

joe_padavano

Yes, the Olds diesel uses the same BOP bellhousing as every other BOP motor. Olds motors that did not come from the factory with a manual trans usually do not have the crank drilled for the pilot bearing. You will need to do this. The 425 crank is likely not as strong as the diesel crank. The gas engine conversions that use this also use custom rods and pistons. Doubt you can get those for a diesel - at least not economically.

olds 307 and 403

And get the injection pump rebuilt. The 4.3 V6 with the extra head bolt is the best Olds diesel to use but much rarer. The 6L Navistar design should have resulted in jobs lost. Using a 4 head bolt per cylinder design was a mistake on the not from clean slate Olds diesel. So 30 years later, use 4 bolts and add boost, good grief.

Olds64

Here is a shop that might be able to rebuild your injection pump:

http://conestogadiesel.com/

I've heard that rebuilt injection pumps from the parts store (if you could even find one for the Olds 350 diesel) are usually inferior to ones rebuilt by specialty shops like the one linked above. Plus, the price of the specialty shop rebuilds are reasonable when compared to ones available from the parts store (at least with the International IDI IPs).

It's my understanding that the Stanadyne DB2 (Roosamaster) injection pump used on the Olds 350 diesel is the same IP used by International on the 6.9L and 7.3L IDI. It was also used by GM on the 6.2L and 6.5L Detroit diesels. I'm sure there are internal differences though.

Here's a cool article on the Stanadyne IP:

http://www.trucktrend.com/how-to/exp...njection-pump/

olds 307 and 403

It looks like those pumps are only good for 200 hp. Either way a big power upgrade.