Dean's List gets another motor

[alldodge]

I was bored and didn't want to do glass work, so decided to do motor work


My buddy Dean has a twin engine cruiser with V-drive 454 MPI's. The Port motor has been replaced twice, get that twice. Some years ago the previous owner had the motor replaced by Merc dealer with a Reman. Motor SN 91003823 and list .030 bored, and .020 mains and Rods.


Reason motor needed to be replaced 2nd time was it spun a rod bearing. Spun bearing is most always the crank was not turned correctly and has a taper in the journal. The rod bearing spun so have had the motor in my barn for a few years.

OK, starboard motor has been having trouble with power. We do the yearly checks and the the compression is lower. Notice that there are 2 different pistons installed by rebuilder. Other then the piston and crank, all looks ok. Going to press the 2 off and measure the weight of each to compare.




Going to boil the block the block out, and motor had only about 25 hours before the bearing spun (not used much).

 

[Rick Stephens]

Sloppy and carefree mixing pistons. Tells you a lot about what to expect.

 

[Scott Danforth]

was it cylinder #3 or #4

get the block line-honed and decked. you will find you need to true up the deck slightly

 

[Scott Danforth]

scat forged rods are cheaper than reconditioning the stock rods

 

[alldodge]

was it cylinder #3 or #4

2 AND 4 have those pistons on the left, the rest have the ones on the right

We will measure the "flatness" of the block and heads. If they need attention, we will then have that done

 

[alldodge]

Have a new Eagle crank and standard bearings. Do not plan to do a stroker with a 24K LB cruiser. No way that would help much at all

 

[Scott Danforth]

2 AND 4 have those pistons on the left, the rest have the ones on the right

We will measure the "flatness" of the block and heads. If they need attention, we will then have that done

referring to the spun rod.

the last two Gen VI's I pulled apart had either 1 or both of them spun

 

[Scott Danforth]

the double roller timing chain set I picked up fit under the factory cover, if you are interested, let me dig for that info. I upgraded to coated bearings

both Melling and Mahle offer a higher psi spring for a pressure relieve on pumps.

 

[alldodge]

We did find a spun bearing, right now don't remember which one it was, will state later. No need for double chain, original is in good shape.

Dean did buy high dollar bearings, mentioned why did you want to do that? All I can say is it's a Dean thing

 

[Scott Danforth]

We did find a spun bearing, right now don't remember which one it was, will state later. Bo need for double chain, original is in good shape.

Dean did buy high dollar bearings, mentioned why did you want to do that? All I can say is it's a Dean thing

talking to Scotty over at innovation marine. the coated bearings saved most of their high $ race motors when something goes awry (dry sump line breaks, etc) that is why I went coated.

double roller because I needed to buy a new chain and it was same price as the GM leaf chain.

 

[alldodge]

2 AND 4 have those pistons on the left, the rest have the ones on the right

Need to restate the piston on the left i=was found on cylinders 2 and 3 (not 2 and 4). They are across from one another on the same journal. Figure they put them on same to "try" and compensate if there are different weights in pistons.

Could press the pistons off and measure the weight

 

[alldodge]

Weighed a few pistons and rods as assembly, uncleaned
2 and 3 = 4 lb 1.60 to 1.62
A few others = 4 lb 2.20 to 2.24

And #8 was spun

 

[alldodge]

Decided to get new pistons and rods
Now just need to find right part numbers for the kit. Scat website is not a great help

 

[Scott Danforth]

Decided to get new pistons and rods
Now just need to find right part numbers for the kit. Scat website is not a great help

Use summit racing website to get part number. Then Google around. Summit will match prices. When I get home, I can look up part number. (I think there is a pic of the box in my build thread). Currently at doc office

 

[alldodge]

Heads went to the shop and found some bent valves. The guides were all drilled out and bronze bushings were pressed in, cheap fix. So we have a Merc Reman that had several problems. So much for Merc quality

Heads should be back next week and can start putting it back together.

 

[Scott Danforth]

So much for Merc quality

cant make money with all their overhead to do it right, so shortcuts are often taken

 

[Rick Stephens]

cant make money with all their overhead to do it right, so shortcuts are often taken

Mindblowing. Customer service and support costs much more than the initial savings.

 

[Scott Danforth]

Mindblowing. Customer service and support costs much more than the initial savings.

unless they deny the claims

 

[Bondo]

I was bored and didn't want to do glass work, so decided to do motor work
View attachment 361855

My buddy Dean has a twin engine cruiser with V-drive 454 MPI's.

Ayuh,..... Yer shop,..?? or Dean's,..??

Looks really organized compared to mine,......

 

[alldodge]

Ayuh,..... Yer shop,..?? or Dean's,..??

Looks really organized compared to mine,......

That's my shop

I think after 6 years I'm also going to get the little boat put back together also. Sure hope so