Help with engine identification...
 

I know it's Offshore Only but I found such good info on this site reading I thought I would ask you guys help me dial in my engine.

I bought a 1997 boat with a Volvo Pental 7.4L. Buddy has the engine out for a rebuilt and can find no OEM decals/plates for indemnification. So I guess the next step is find some casting numbers and start reverse engineering GM data. Since the boat is a 1997 and we believe the drive train is original I'm guessing it's a

L29 Gen 6 7.4L Vortec (with MPI), but...

What is Volvo's designation for this setup during those years? Since there is no decal and I'm trying to get the correct parts and repair manuals. Is it a GL, GI, GS, blah, blah....FYI it had a Duo Pro setup.

I read a few articles on here where a few guy has scary knowledge of engines by year...so I'm hoping they are lerking on here quiet a bit!

Thx all!

hello , you should find block casting number on left side rear area,you should be able get info from casting number

https://cimg5.ibsrv.net/gimg/www.off...5ed874e641.jpg

https://cimg0.ibsrv.net/gimg/www.off...0bf196ea95.jpg


i would try , doing a search, type block number chevy motor
good luck

CC,
Exactly what information are you looking for ? If you are going to actually rebuild it once you have it disassembled you will be able to easily identify all of the parts except maybe the camshaft.

Buddy is rebuilding the engine. We found the casting numbersBlock: 12550313...454.......91-up...4-bolt, Gen.V crate motor, Gen. VI 4.25" bare block, fuel pump boss
Head: 10141279...96-up...oval..CLOSED.."Vortec 7400", 100cc chambers
What I'm looking for is what Volvo called this engine setup. I see references to GI GXI, etc but cannot make heads or tails of what VP was calling this setup.

Still some confusion based on those block data above if it's a Gen. V or Gen. VI. I'll assume that it's NOT a crate and VP gets the blocks and builds their own? All date points to the fact this should be a Gen VI if it has the 96+ heads and it's call Vortec 7400. Anyone agree?

So my buddy said it would be great to have a manual of sorts for torque specs and we figured those VP manuals all over eBay would be helpful.

gen 5 vs,gen 6 look at the timing cover.... As for volvo...I only know merc stuff......

Read those 2 sentences. If your buddy needs the manual and can not differentiate between Gen 5 and 6, should he be rebuilding the engine?
Not trying to be an a$$.

Boat title possible serial numbers on it. How about a drive serial number. I am a factory OEM Volvo trained tech for about 30
years now.

Snap some pics of the intake and ecm as well. That can possible tell what year and exact model you have.

GL and GS were CARB engines ONLY - your engine is going to be a Gi or a GXI model for your 7.4.mpi

Added info --- Volvo NEVER used MEFI 2 ever, they used MEFI 1 and 3 and 4 then went to E controls in 2005.

Mefi 1 had the side connectors - Mefi 3 and 4 had the front connectors and was a smaller ecm compared to MEFI 1.

Bup, Thanks for the great intel...unlike the last guy who only brought shade to the party!

The boat is about 1.5 hrs from me so I won't be able to grab ECM or the outdrive but it is a duo prop if that helps with the Gi vs GXi (it has MFI if I didn't mention that). No luck on my title (came from a state that didn't require engine specs). No label left on intake but I'll include the two photos I got that may shed some light. Sounds like we know it's a Gen 6, which should help with a manual and torque specs.

Was GXi just more rpm/hp?

EDIT: I guess I'm to new to post photos or URLs, boo!
EDIT2: Man, I can find nothing on 7.4L with Gi vs GXi...other then "extra special"! Different ECM programing?

Volvo the G stands for General Motors block --- The X stands for superior output per volvo but some call it exceptional output or some call it extra output or some call extra performance / HP and THE i stands for injected meaning fuel injected.

Gi stands for General motors block and the I stands for injected meaning fuel injected.

And that's how volvo lists and the meaning of their engines.

I know a thing or 2 about some of this marine stuff haha,

He wasn't throwing shade, he was trying to save you butt hurt. True boat motors are not rocket science, buts its really easy to due something that while great on a car, willnot work on a boat motor,

Sorry...I don't see It that way with the comment. I'm posting questions on three different forums for assistance. Eventually someone starts giving opinions on how we have no clue what we are doing based on our questions/comments and we are making huge mistakes. Nobody said anything about him wrenching only on cars so that was a assumption to defend a point. He had concern because my buddy wasn't experienced enough to know the difference between a Gen V and a Gen VI yet we knew enough to ask the right questions.

To get back on topic how is the best way to determine Gi vs GXi or is that going to come from the ECU numbers?

I wasn't trying to "bring shade to the party". I have been on this forum long enough to know at the end of the summer every year, we have new members start the same thread and the results are 80% bad the next spring. I'm just asking you to evaluate the situation with an open mind.
There is a ton of knowledge on this forum, Welcome to OSO:)
Thanks phragel, you're not as bad as they say... lol