Nice to know the iron block is so robust. The bottom end is very stout. The cylinders are almost 1/4" thick.

Use cams with new rockers, etc
 

For my project I acquired some camshafts with "matching" rockers. My assertion is once the cams/rockers are installed on a different engine they are no longer matching. I doubt a different head can place the rocker in the exact same relationship with the cam. So questions: How important is matching rockers? I hear of people swapping cams and they work just fine but one does not hear about the failures. Are Febi Bilstein rockers quality? I have heard of some replacement rockers failing. I would assume no problem with used cams/new rockers. They are hydraulic cams.

I wouldn't worry too much about re-using rockers, especially if you have it matched to the corresponding lobe, but even then. Unless they are worn a significant amount. The most important thing I'd think is finding a high-zinc oil for the shear these sliding rockers have.

Thanks Tom. That is high on the list when the time comes. I wonder if cams and followers can be micropolished like crank journals?

Thank God for youtube. I found my answer:
https://www.youtube.com/watch?v=ZnSJPGHJQok
Wait until he whips out the hacksaw with the shoelace on it.

I might need to name my next race car the Manitoba special [emoji23][emoji1787][emoji23]

I guess you could polish the following surface. If you take much off it would change the geometry though. I'm not sure how much wiggle room you have on the, "hydraulic lifter" or really "cam follower stand", growing to fill lost material. I guess we're talking about ten thou's though. Did you mix up followers or just have a pair of cams without the originals? Or are you just talking about the actual ballstud stands themselves?

Sent from my SM-J737A using Tapatalk

The cams and followers are matched. Not the ball studs. I have seen micro polishing for cams but it is mostly new and reground. It's done on cranks all the time. I don't think most people re use camshafts so that's probably why it's not done. The process only removes microns but creates a low friction surface.

Head Gaskets
 

This thread really should be in Performance Paddock-does anyone know how to move it?
I had anticipated having the bores increased on stock 92mm 4.5 head gaskets to 96.5mm but no one will do it. I guess the coolant passages in the gaskets are too big and close to the bores. So I have 2 choices-customs which will be very expensive for 1 off or 5.6 gaskets which are like $40. The 5.6 gaskets would work with some minor enlarging of a few ports that don't line up perfectly but the matching holes are much smaller so they may not need much at all. My concern was the difference in thickness-the 4.5 gaskets are .075" and the 5.6 are .05". I'm not concerned with the cam timing change. I was more concerned that the 5.6 gaskets were for a aluminum block with aluminum heads. Not sure why it would matter as the 4.5 and 5.6 gaskets are the same construction except the thickness. Alu heads on a iron block are common with all kinds and thickness of head gaskets. I know having the proper RA is important. Any thoughts?

5.6 gaskets :thumbsup: & slot five bolt holes.
RA? Resonance Amplitude? Rat's Arse?

Ra=Roughness Average or surface roughness. Heads & block should have correct Ra for head gasket sealing.

Why hasn't anyone mentioned facing the 560 heads .030" or so for increased compression? I can't imagine valve to piston clearance being an issue.

Also, there are companies that will weld and re-grind camshafts. Years ago I worked part time for a guy that builds motorcycle engines. A well known name in the industry, not some guy working out of his garage. Almost every head he sent out the door had 2 welded camshafts in it. He said he's never had an issue and that the surface they put on by welding is better than the parent material of the camshaft anyways.

This is the place he used:

Web Cam Inc.

Question 6 on their website:

Hardweld vs. billet
Web Cam offers both hardwelded cams and billet cams for many applications. We believe that our hardwelding process is the best option in extreme racing conditions. We offer billet cams for people that do not want to send in their stock OEM camshaft for welding, and are not demanding as much from their engine. When you buy a billet camshaft, you will avoid the core charge.

For my particular situation I can increase CR by reducing piston dish volume. Stock cams are fine for me.

560 Heads update
 

I machined one of the 5 misaligned 560 cam tower head bolt holes and a used 560 head gasket (wrong side)-I have some new gaskets ordered. I believe the holes were moved on the 560 to account for the larger bore as the 4.5 bolt hole location is quite close to the bore once the 4.5 block is bored. That was my main concern-that the area of the heat ring around the relocated hole would be too small. I machined the hole by hand very slowly removing only the minimum material needed as to keep the space between the hole and cylinder as large as possible-same with the gasket. there was a small loss of heat ring but still plenty width. I would say at this point I have resolved all my 560 head related issues.
head pic shows un and machined hole for comparison.

Plugging air injection holes in exhaust ports
 

I was thinking of tapping the holes and plugging with aluminum bolts. anyone done this?

How thick is the port wall at the air hole?