WD45 Engine Rebuild

About 5 years ago when I painted my WD45 I pulled the engine, installed a new clutch, had the flywheel surfaced, and put a full gasket kit in the motor because the cork was rotted on the head gasket and was leaking. It had M&W’s in it and the pistons, sleeves, and bearings all looked good. I’ve only put 100-200 hours since then.

After working it hard for a few hours the spring, the head gasket was leaking oil so I pulled head off to have it checked and milled and saw the front sleeve was scored. Pulled the pan and the bearings were lightly scored and there was some soft gasket sealer that flaked off in the pan and some orange paint chips. So I’m going to rebuild the whole thing and want to make sure I do it right. I’m not a mechanic so I’d be happy for any knowledgeable advice.

I want to have the head hot tanked and machined to true up all mating surfaces. Install new hardened valve seats.

I want to get new cam bushings and grind the crank. I’m also thinking about getting the block line bored and the rods bored to remove any shims. Is this actually worth the money?

Should I get the engine internally balanced or is that a waste of money at these low rpms?

I’m trying to decide what engine kit would give me the most power and reliability. I’ve got what looks like another good set of M&W piston I could use. Would I get more power out of the M&W’s with the 4.125 bore at 7.3:1 compression or a 4” 175 kit at 8.25:1? My guess is that they would be almost the same.

I was reading some of the posts of converting to a full flow oiling system. Is this very difficult for a novice and what’s an approximate cost? Will the stock filter handle that much oil flow? Is it easy to get a D17IV oil pump?

Please let me know if I should be doing anything else, and thank you in advance.

Edited by Allis dave - 04 Dec 2015 at 7:34am

One summer I disassembled 8-9 '45 engines, after having the cranks checked, discovered those with M&W pistons most likely showed cracking when magna fluxed.

Whenever you have a crankshaft re-ground, your Machinist better be magnafluxing it checking for cracks to be sure it's worthy of re-grinding.

Line boring is something to do on an "as needed" basis. I had to line bore my CA engine because the center main was far enough out of position that even though I had .002 clearance on all 3 mains, the crank could not be turned with the caps torqued. Balancing can't hurt, and could make a smoother running engine, but the gains may not be worth the extra expense.

Allis dave wrote: Don, Did you make that wrench?

No, I didn't make this one, it was built by Snap-on.


Edited by Don(MO) - 04 Dec 2015 at 5:16pm

WF owner wrote: Don(MO) wrote: Allis dave wrote: Don, Did you make that wrench? No, I didn't make this one, it was built by Snap-on. I believe those wrenches were for distributors.

Sorry but they are built just for this and they are not distributor wrenches. I have four or five dif one's to get in or around stuff on heads to tighten bolts/nuts. 

Is that a special made tool for that job Don? Seems like A-C used Kent-Moore aka Spent More for their special tools, but Snap On and the rest are good at coming up with solutions too.

That's great Don, Thanks! I just bought one off e-bay. $20 including shipping. Worth it to make sure everything is torques correctly.