1973 Rebuild

[Matthew Abate]

New toys arrived earlier this week from Zed Findings.

Edited February 26, 2016 by Matthew Abate

[Kurbycar32]

Looks oh so familiar!

[Matthew Abate]

More metal sex (p90a in great condition):

Shot camshaft, though (good thing I don't want it, but I had planned to resell it):

[rossiz]

why not use it as a core for a re-grind? the japan cams are good steel and you can get whatever custom grind you want out of it.

[Matthew Abate]

On February 29, 2016 at 8:25 PM, rossiz said:

why not use it as a core for a re-grind? the japan cams are good steel and you can get whatever custom grind you want out of it.

Because my machinist gave me a bunch of bad news on the rest of the head. There is a hole in the #1 exhaust port (dark spot in left center of the port). The head looks good otherwise, but the hole could be deep enough to make the water jacket metal thin. Tig welding the hole could be "tricky". Also, one of the valve springs was installed upside down!

A pressure check will run about $60; tear down and reassembly about $80, I will probably need new seals for about $45, and as I've already said, the cam is shot. So, I could pressure test it and find out that everything is fine, but I have still paid for something that was supposed to be ready to go, but isn't. I'm waiting for him to get back to me on how he plans to make it right.

Also, don't hydraulic lifters require the round part of the cam to be stock diameter, regardless of lobe profile?

 

Edited March 1, 2016 by Matthew Abate

[Zed Head]

1 hour ago, Matthew Abate said:

Also, don't hydraulic lifters require the round part of the cam to be stock diameter, regardless of lobe profile?

I think that you would get new lash pads with a new cam grind and that would get the hydraulic pivots (they're not really "lifters") back to the right range.  Many people swap the hydraulic pivots to solid, with Timersert inserts (to get the proper thread in the hole).  The hydraulics can fail and I don't think they're available anymore.

A P79 head would give you 8.8 CR with those pistons, or an N42 or N47, about 9.8.  

[rossiz]

teardown, reassembly and new seals are easy money to save - several threads on this forum showing how to do this (including one or two that i've posted) and i can assure you it's not rocket science. all you need are a clean bench, a few simple tools (spring compressor, feeler gauge and a crows-foot for the valve lash adjust - all cheap) and you'll soon be good to go. the cam doesn't look "shot" to me, just needs a re-grind. i believe Blue posted a pic of a cam that had been sitting in an open engine (no valve cover) for years and looked as rusty as a boat anchor and it cleaned up & re-ground just fine. i'm also pretty sure you can find a shop to weld up the hole and grind smooth, this happens a lot while porting and it shouldn't be big $$.

head work is what makes these engines come to life, so learning how to get in there and do the basics (cam & lash pads, CR adjustment, de-shrouding, basic port clean-up) will really empower you to get the most out of your mill and have some fun in the process. really, it's waaaaay more fun than rust repair!!

 

[Matthew Abate]

Cleaning up the F54...

Deck is nice and flat. Only needs 0.003 off to be perfect. Anyone know if these jets can come out?

Sent from my iPhone using Tapatalk

[madkaw]

Don't want to take them out

[Matthew Abate]

Okay.

But how are you guys cleaning the oil gallery then?

[grannyknot]

12 hours ago, Matthew Abate said:

 

Okay.

But how are you guys cleaning the oil gallery then?

I did those oil gallery holes alternating with spray can brake cleaner then compressed air, then carb cleaner and compressed air. I kept that up until it was dripping clear cleaning fluid.

Chris

[Matthew Abate]

More stuff (thanks Patcon!):