120 L-drive crank. Can it be ground or where to buy a new one?

[brandonv]

I finally got around to tearing the motor down and all 4 cylinders are toast as are the crank journals for rods #1 and #2. They're galled and either need to be ground or I need a new crank. Does anyone know if it can be ground and if I can get oversize bearing pins? Or where I can get a new crank for a reasonable price?

Thank you!

PS-there's a used one on ebay for $75, but it doesn't state its for an l-drive. Are the cranks interchangeable between the outboard and L?

 

[Frank Acampora]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

Some remanufacturers say that the crank can be ground, but I say that the factory used a special process to harden it during manufacture and it can not be ground.

Even if you did have it ground, it would cost more than buying a used one.

The block on the outboard and L Drive were the same BUT---the 120 was made in several versions And I am not certain but I believe that two different stroke cranks were used. The cranks will interchange in the block but the port timing will be changed resulting in slightly reduced power. SO: you need to be certain the crank you want to buy is the same stroke as the crank you now have. Standard 120 has 2.80 stroke. Some 120s might have 2.875 stroke, and most 125s had 2.875 stroke.
See my private message to you.

 

[Frank Acampora]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

I didn't mention in the previous thread. If your machine shop is any good, they will mike the cylinder and tell you how much oversize to bore it. -- WISECO offers pistons in .020, .030, and .040 oversize.

The standard cylinder diameter will either be 3.3125 or 3.375. The machine shop overbores over the standard. The pistons are sized to fit. So, for example:

If the cylinder is 3.375 and it needs .030 to clean it up, the shop bores and finish hones to 3.405 and an .030 oversized piston will have the proper clearance.

 

[Frank Acampora]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

Learn something new every day! Verrrry interesting!

Even though the block, pistons and con rods for the Ldrive were the same as outboards, The crank is balanced differently. Reason?---something to do with the different position of the block.

Franz at franzmarine@aol.com has them but they won't be cheap.

 

[CharlieB]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

L-drive cranks are different, and yes they can be spray-welded, re-ground to original size, and surface hardened to meet or exceed OEM standards.

There are only TWO machine shops that I consider competent to handle this

Call Dan at Outboard Crankshaft
Lynnwood, WA
425 744-0626

or

Call David at Marine Crankshaft
Santa Anna, CA
714 549-2388

Either shop will make a believer of you once you see and run with their work.

I also highly recommend Pro Marine or OEM pistons over the Wiseco's

Wiseco's work fine in motorcycles, you are working on an outboard, totally different beast, granted, they are both 2-strokes, other than that, they are worlds apart.

 

[brandonv]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

Big thanks guys!

$400 (after $85 core charge) for a remanu crank from Outboard Crankshaft. Its still cold and crappy here in Portland, so I'll hold out and see if a used one hits ebay. Thanks for the info folks!

 

[Frank Acampora]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

Charlie: I'm always open to new ideas. I have a couple of poor cranks that right now I don't have a pressing need for.

So, what do these re-grinders charge? Is it a flat rate per crank or is it by each bearing surface they refinish?

Only problem is with shipping out there and back, then the labor charge, I can hunt up a good used one for less money.

Still----Might be worth a couple of bucks to experiment--Throw one in an engine with no great expectations and see how well it holds up.

As for Wiseco--Some guys swear by them, some swear at them. I have heard both sides of the argument. I have had good luck with the ones I have installed.

 

[newbie4life]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

I have a crank in my L-drive that was ground. My BIL had a machine shop in the Minneapolis that he uses for his auto shop grind the thing. When he got it back, he called me and told me about it... He was impressed. And he's the type of guy that isn't impressed very easily. He kept saying it looks like brand new.

I didn't pay attention to the technical jargon, but I'm guessing there's more than 2 competent machine shops in the United States that could handle this task.

It did take awhile though. It was almost two weeks, because they have such a backlog.

 

[newbie4life]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

All that, and I forgot to mention what it cost. $84.00 with tax.

 

[brandonv]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

All that, and I forgot to mention what it cost. $84.00 with tax.

$84!?!?!?
Got a name and number?

 

[CharlieB]

Re: 120 L-drive crank. Can it be ground or where to buy a new one?

Sorry for the late date iin responding.

$84.00 for regrinding and polishing one journal is not a bad price for an automotive crank using babbit bearings.

HOWEVER...........

A two stroke crank using roller needle bearings the crank journals MUST BE hardened.

Without surface hardening the bearings will work, long enough to sell the boat/motor, then great glorious destruction will occur as the crank journal wears away, the needles get hot and smear around the surface, then the rod comes apart! Blowing out the side of the engine cases!!!!!

Moral of this story?

You get what you pay for!

Spend the money and have the crank done RIGHT!!!