NEW 360 LA CRATE TEARDOWN

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QUINN FORBES

QUINN FORBES

Greendemon
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“908” LA 360 crate motor out of hibernation after 15 ish years!
Going in the Demon after full teardown and inspection.
CDC9D2DC-2F4C-4DF5-89E5-CA1357DDEEFD.jpeg
Greased/oiled by me years ago. Nasty but very effective.

69C068E8-D45B-4AE6-BF76-D653C756AFDD.jpeg
403091?
132965A2-927D-4215-886F-5C89A5235FF5.jpeg
360TOR1713
204
760 at the deck.
Don't know what these number represent!?


129481D6-F274-4C86-807F-C2A7587034FA.jpeg

Oil galley plug not installed straight but does not leak and cam thrust plate should cover this up anyway.

2EAD93BE-484A-4027-895E-98DCE723D811.jpeg
Cummins decal.

F1F0030F-9371-4F30-B673-A7316B5E41EF.jpeg

5A05586B-BB6A-4CD2-B69F-B0E02A63E62C.jpeg
Cam bearings scratched up a bit but no major gouges by the fingernail test.

0238145E-51CD-4247-AE70-0BBB2A191C43.jpeg
Rod bearing/journal clunked against crank counterweight when installed.
Since been remedied,
No damage to bearing.

The quality of these parts are good but the workmanship lacking.
So far not great but could be worse from some other tales of these blocks.
I traded this crate for an 8 3/4 dart housing/axles and some hogged max wedge heads so I don't have much invested. Still no matter the initial cost I would still be disappointed if a rod bearing/journal got munched or worse.
Next will be crank and rods go back in to be torqued since I have gone over them closely. With crank polished and mic’d and plastic guaged and rods/pistons rechecked, they will go back in after thorough block cleaing.
I will install a pump and pan to prime oil with break-in oil for assurance everything is oiling.
More soon…
 
QUINN FORBES said:
“908” LA 360 crate motor out of hibernation after 15 ish years!
Going in the Demon after full teardown and inspection.
View attachment 1716064055
Greased/oiled by me years ago. Nasty but very effective.

View attachment 1716064059
403091?
View attachment 1716064068
360TOR1713
204
760 at the deck.
Don't know what these number represent!?


View attachment 1716064063

Oil galley plug not installed straight but does not leak and cam thrust plate should cover this up anyway.

View attachment 1716064071
Cummins decal.

View attachment 1716064072

View attachment 1716064074
Cam bearings scratched up a bit but no major gouges by the fingernail test.

View attachment 1716064080
Rod bearing/journal clunked against crank counterweight when installed.
Since been remedied,
No damage to bearing.

The quality of these parts are good but the workmanship lacking.
So far not great but could be worse from some other tales of these blocks.
I traded this crate for an 8 3/4 dart housing/axles and some hogged max wedge heads so I don't have much invested. Still no matter the initial cost I would still be disappointed if a rod bearing/journal got munched or worse.
Next will be crank and rods go back in to be torqued since I have gone over them closely. With crank polished and mic’d and plastic guaged and rods/pistons rechecked, they will go back in after thorough block cleaing.
I will install a pump and pan to prime oil with break-in oil for assurance everything is oiling.
More soon…
Click to expand...
Short blocks were untouched factory units.
 
Did that come with a flat tappet cam? It looks like it has the bosses to run factory roller lifters. Is that part of the plan?
 
qkcuda said:
Did that come with a flat tappet cam? It looks like it has the bosses to run factory roller lifters. Is that part of the plan?
Click to expand...
Depending on the year (from like 85-93) mopar had blocks that were LA blocks but had the spider mounts and bores for OEM rollers... i have a 318 like that and am trying to find a 360 right now :(
 
I think the 360’s with roller were mostly in trucks. Not sure.
Lots of 318’s available because of the 5th ave’s but not too many 360 rollers around here.
 
QUINN FORBES said:
I think the 360’s with roller were mostly in trucks. Not sure.
Lots of 318’s available because of the 5th ave’s but not too many 360 rollers around here.
Click to expand...
Yup, my 318 was a truck motor.. which sucks.. i wish it had the car mounts not long truck mounts
 
QUINN FORBES said:
Hi Mr. Sinister, how do you mean “untouched factory blocks”?
Click to expand...
The crate motors came to us dressed as a production truck motor we pulled off the breadbox intake, distributor, exhaust manifolds, truck oil pans, timing chain cover, gear sets, oil pump and pickup, camshaft and lifters, and cylinder heads. Nothing else was removed from the short block. The cylinder heads got a 3 angle valve job, a new camshaft and lifters installed and degreed in a fuel pump eccentric was added ( magnum cams don’t accept pump eccentric ) a double roller timing set, an early style timing cover, car type oil pan and pickup, the heads and new gaskets installed, an M1 single 4 barrel intake, and a Mopar performance vacuum advance distributor.
 
With all of the variations of Mopar Performance engines & short blocks, information can get confusing.

Things got started with the original Mopar Performance Commando 360/300hp and Super Commando 360/360hp engines with LA blocks and heads. Cams were .474" and .484" hydraulics respectively. I believe they came out around when Magnums were replacing LA 360's in production vehicles. (Early-mid 1990's ?)

Bobzilla is correct in noting that what OP Quinn Forbes has is a crate replacement short block, which Mopar performance made available later. Mr. Sinister is correct in stating that crate engines used "untouched" short blocks, but that was with Magnum engines which came even later! (Note that he mentioned "breadbox" intakes (Fuel injection) and Magnum cams which were replaced and LA related parts added there.

There are more details available about them but it will take some digging here at home. The crate engine offerings spider-webbed after that with aluminum heads, big blocks, etc. Just trying to keep people aware and information as correct as possible.

Quinn Forbes - I would like to see a photo of the deck & pistons.
 
Last edited:
That is a different engine than what we were prepping and yes we were doing MAGNUM crate motors.
If I added confusion, that it is not my intention to.
 
Confusion indeed!
I have two different mopar catalogues with the same P4876908 part number.
the only difference being pin height.
Crate engine catalog states this block is 10:1 comp with cast heads (587 or 596)
The 2005 mp catalogue says 9.1:1 with the same heads.
The only difference being pin height.
My calculations tell me Im in the 9’s for compression due to the pistons at top being in the hole a c hair.
About .024 in the hole.
Maybe the Cummins built here in Canader had lower compression?
FE83D62E-3AC2-4CEA-BE4A-B5B1FD99D0BA.jpeg

D4F57C57-F181-4359-9BC1-CCDEEB19AEE9.jpeg
 
No I wont be going roller cam due to budget.
I have everything here to build it as flat tappet.
Comp xe268 and new crower lifters.
This block was built/shipped as short with no heads assembled on it.
 
Mr. Sinister said:
That is a different engine than what we were prepping and yes we were doing MAGNUM crate motors.
If I added confusion, that it is not my intention to.
Click to expand...
No problem. Kinda wish it was a magnum though, less confusing due to the LA 360’s being built in two different factorys.
 
QUINN FORBES said:
Confusion indeed!
I have two different mopar catalogues with the same P4876908 part number.
the only difference being pin height.
Crate engine catalog states this block is 10:1 comp with cast heads (587 or 596)
The 2005 mp catalogue says 9.1:1 with the same heads.
The only difference being pin height.
My calculations tell me Im in the 9’s for compression due to the pistons at top being in the hole a c hair.
About .024 in the hole.
Maybe the Cummins built here in Canader had lower compression?
View attachment 1716064221

View attachment 1716064222
Click to expand...
*Sorry piston height not pin height
 
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