8V92 Twin turbo supercharged 735Hp Detroit

[ohiwafishing]

Hi guy's/ Girls.

Is there any Two stroke Detroit gurus out there?
I have a 45ft Charter boat running a 8V92 twin turbo supercharged Detroit 735Hp driving a Hamilton Jet.
I have just brought a USA Military 8V92 single turbo engine apparently from a Oshkosh. It is like brand new. I am wanting to make it a 735Hp engine as a spare. Does anyone no what I need to change to make it into the same engine as I have got??

The Detroit agents in New Zealand seem to only want to sell me something. They reckon I need to put a piston and liner kit in it. Replace the cams/ Injectors etc. I don't really want to put a brand new rebuild kit in a nearly brand new engine if I don't have to.

Diesel Pro USA only list two types of rebuild kits. Turbo/ Non turbo. Same with the cam shafts. Turbo and non turbo.
So does anyone no if I have to do a full rebuild to make it the same engine or what exactly I need to do and change?
Thanks

 

[Pascal]

Have you tried getting in touch with diesel pro? They’re pretty big here in Miami. and do a lot of export. They may not list other options but should know what you need.

 

[ohiwafishing]

Have you tried getting in touch with diesel pro? They’re pretty big here in Miami. and do a lot of export. They may not list other options but should know what you need.

No I have not tried asking them. I have brought all my parts and rebuild kits off them in the past. I really want confirmation that all I need to do is put the 735Hp injectors into it. Bolt on all my external parts manifolds and turbos and I have a 735Hp engine.

Thanks for your reply.

 

[osprey]

Different turbos, intercooler, exhaust risers and fuel injectors to start with, and that's already 10 thousand dollars NZ at least. Very difficult to change a complete engine in a boat. the engine would be better to used for spares, rather then modifying to higher HP. In my opinion. P

 

[osprey]

By the way, what is the HP rating of the spare engine? P

 

[SKYCHENEY]

An Oshkosh truck engine is not a marinized engine. Do you currently have a dry manifold or wet? Heat exchanger or keel cooler? It seems just the marinization alone would be cost prohibitive.

 

[ohiwafishing]

By the way, what is the HP rating of the spare engine? P

Hey,

Thanks for your reply.

Maybe I did not word my original post very good.

My engine in the boat is already marinized and running nicely. Only about 500hr on its brand new rebuild. As this is a very busy Charter boat it cost me thousands of dollars in lost bookings for the 7 weeks it was waiting for the engine to get rebuilt plus the rebuild cost etc Not to mention the thousands in Air freighting parts from all over the USA. I also had new manifolds and risers come for the engine but got lost in transit so they never got put on. They are sitting in my shed.

As the boat is a open deck hooked directly to the jet. No gearbox. Raw cooling water is supplied from the jet so no water pumps etc it only takes about an hour to remove the engine.

What I am wanting is to have this new spare motor sitting there read to bolt my heat exchanger/ manifolds turbos on and its ready to go to work the next day.

The new engine has 9A90 injectors giving it a Hp rating of 430Hp

 

[ohiwafishing]

An Oshkosh truck engine is not a marinized engine. Do you currently have a dry manifold or wet? Heat exchanger or keel cooler? It seems just the marinization alone would be cost prohibitive.

Hey,

I already have every thing to bolt on it for it to be marinized from my complete running engine that's still in the boat.

This new engine is pretty much brand new rebuild from Detroit. By the looks its maybe only run in hours.

I just want it as a spare ready to bolt my heat exchangers etc on and it is back to work the next day.

Thanks

 

[Captain Ralph]

You need to research what you have now. With the serial numbers, you can determine what the factory tune is (advanced cam, blower ratio, by-pass blower for examples).
Then check into the spare engine serial number for the same info and compare.

I'm sure the short blocks will match. Oil pan, cooler and oil pump may not. Flywheel and dampener probably will not match either. Without matching up the serial numbers, no telling on the blower / cam data.

Sorry I'm not painting a pretty picture for you but there are lots of little things other than just injectors.

How long has your new spare engine been sitting? If it's been a paper weight for a couple of years, I would consider an in depth inspection if not rebuilt.

 

[rustybucket]

Good plan to have a spare engine on-hand. I'm not a detroit guru by any means but timing is probably advanced a tooth on your 735hp engine, it may or may not be advanced on the new engine. I think some 892's came with 2 valve heads as well, so might be worth verifying you have the 4 valve heads on the new engine.

RPM diesel in lauderdale might be able to rebuild your injectors to the 735hp specs. They seem to be very knowledgeable about detroits so it may be beneficial to call them, tell them what you are trying to do and get input/feedback from them on what all it will take. Diesel Pro is another good resource, I'd give them a call also.

Pulleys...etc may be different as well on the front of the engine.

After getting the new engine built or adjusted correctly you will need to pickle it somehow to keep the cylinder liners from rusting. I think the detroit manual has procedure on pickling them.

 

[rsmith]

You would be better asking questions on the Detroit Diesel group on Facebook.

 

[ohiwafishing]

You need to research what you have now. With the serial numbers, you can determine what the factory tune is (advanced cam, blower ratio, by-pass blower for examples).
Then check into the spare engine serial number for the same info and compare.

I'm sure the short blocks will match. Oil pan, cooler and oil pump may not. Flywheel and dampener probably will not match either. Without matching up the serial numbers, no telling on the blower / cam data.

Sorry I'm not painting a pretty picture for you but there are lots of little things other than just injectors.

How long has your new spare engine been sitting? If it's been a paper weight for a couple of years, I would consider an in depth inspection if not rebuilt.

Thanks for your info.

I am not having any luck with the engine serial numbers on both engines. I am not sure why both engines I have have engine numbers starting with 8FF which do not correspond with anything. Maybe its a reman engine number I am not sure.

I thought I would have to change the crank timing to a A timing. That's no issue as its on a stand in the shed.

I guess what I was hoping for here was someone to tell me there are only two different cam shafts. Turbo and Non and same with the rings and liners. That's not looking like the case now. I am guessing I will have to pull the heads off to get cam numbers etc. The rebuild tag only has date, STD Bore, STD Crank, STD Rods. Eng s/n 8FF6242 Eng M/N 8087-7899. The last number comes up as Military Oshkosh engine.

It is just a shame to pull such a nice engine apart. The paint on all the head bolts/rockers etc from where it was marked as torqued is like the day it had been put on. Even the paint on the valve adjustment nuts has not been broken so it has not even had a top tune. The liners look like it hasn't been run so im guessing its only done dyno hours.

 

[ohiwafishing]

You would be better asking questions on the Detroit Diesel group on Facebook.

Hey there. Yes I just found that page last night. I will see what someone there has to say but its looking like I will have to strip it.

Thanks for your help.

 

[ohiwafishing]

Good plan to have a spare engine on-hand. I'm not a detroit guru by any means but timing is probably advanced a tooth on your 735hp engine, it may or may not be advanced on the new engine. I think some 892's came with 2 valve heads as well, so might be worth verifying you have the 4 valve heads on the new engine.

RPM diesel in lauderdale might be able to rebuild your injectors to the 735hp specs. They seem to be very knowledgeable about detroits so it may be beneficial to call them, tell them what you are trying to do and get input/feedback from them on what all it will take. Diesel Pro is another good resource, I'd give them a call also.

Pulleys...etc may be different as well on the front of the engine.

After getting the new engine built or adjusted correctly you will need to pickle it somehow to keep the cylinder liners from rusting. I think the detroit manual has procedure on pickling them.

Thanks for your help.

I think the timing will need to be advanced but that is no issue. Everyone I call says they need the serial numbers but my numbers on both engines seem to mean nothing. Injectors etc are cheap compared to what we lose in canceled trips if it has a mechanical issue. I like to try and be a step ahead as Detroit parts in NZ are getting hard to find and urgent air freight adds up real fast.

 

[Regal2800]

That is a major undertaking. I would think it's probably cheaper to sell the spare engine you have and buy a rebuilt 735 HP motor. in addition to heat exchangers, turbos, exhaust manifolds injectors etc, I believe the 735HP motors also had different pistons with lower compression ratio. I believe the higher HP motors had 16:1 vs the 17:1 on the lower HP.
Johnson and towers marinized a lot of them. Maybe call them with your serial number and see if they still have the parts breakdown to compare.

 

[ohiwafishing]

That is a major undertaking. I would think it's probably cheaper to sell the spare engine you have and buy a rebuilt 735 HP motor. in addition to heat exchangers, turbos, exhaust manifolds injectors etc, I believe the 735HP motors also had different pistons with lower compression ratio. I believe the higher HP motors had 16:1 vs the 17:1 on the lower HP.
Johnson and towers marinized a lot of them. Maybe call them with your serial number and see if they still have the parts breakdown to compare.

Hey,

Yes that is the question I am trying to find out but seem to get so many different answers. Are the pistons/ Rings/ Liners/ Cams different.

 

[madhatter1]

The starboard engine in my boat was one of the last 8-92 truck engines let go by Detroit. Captain Disesa told me all about wheeling and dealing to get it sold to him. Told me stories about how him and his good friend Roger swapped motors at the end of the residential canal with a hoist system.

He never mentioned anything about changes needed to become a 650 HP marine engine. So it would seem that while there may be timing changes it is mostly bolting up all the 650 HP parts and pieces as an engineered working assembly. My 270 HP 6BTA Cummins have the same internals as the 370 HP version.

Like mentioned in the 700 HP plus version you may need lower compression pistons if the turbos pump that much more air. Join boat diesel.com. Well worth the $25 per year.

Also rather than try to build 100% complete replacement get it internally new and ready to swap out in a couple days using whatever bolt on parts are needed off the engine coming out. That way you have the minimal down time needed and can still source parts over time to eventually have a full replacement engine.

 

[barkdee]

boatdiesel.com A great recommendation... Saved me hours and $s in maintining my 8v92tis.

 

[Captain Ralph]

My engine in the boat is already marinized and running nicely. Only about 500hr on its brand new rebuild.

Who built what you have? They should know the specs to these.

US-Military Detroits were set up to run on JP-5. Standard NATO fuel.
I don't see a lot of cam advance or tall blower ratios on these engines.

 

[ohiwafishing]

The starboard engine in my boat was one of the last 8-92 truck engines let go by Detroit. Captain Disesa told me all about wheeling and dealing to get it sold to him. Told me stories about how him and his good friend Roger swapped motors at the end of the residential canal with a hoist system.

He never mentioned anything about changes needed to become a 650 HP marine engine. So it would seem that while there may be timing changes it is mostly bolting up all the 650 HP parts and pieces as an engineered working assembly. My 270 HP 6BTA Cummins have the same internals as the 370 HP version.

Like mentioned in the 700 HP plus version you may need lower compression pistons if the turbos pump that much more air. Join boat diesel.com. Well worth the $25 per year.

Also rather than try to build 100% complete replacement get it internally new and ready to swap out in a couple days using whatever bolt on parts are needed off the engine coming out. That way you have the minimal down time needed and can still source parts over time to eventually have a full replacement engine.

Hey Madhatter.

Sounds like there were some good stories going around.

Yes I just joined boat diesel and have pretty much been told what you just said. Some 735Hp had different camshafts with different timing. Some didn't and the internals and pretty much the same as my spare is a TTA. Yes that's my plan. I just wanted a complete long block with the correct blower. I already have new exhaust manifolds and risers to go on it so it will be a pretty much complete spare.