Another issue... points cam orientation.

[teazer]

FYI, I had another look at those couple of pics and both valves show clear signs of impact on their lower faces. In the picture, that is the upper/outer faces. there are signs of heavy and repeated impact with "something".

A couple of things to consider:
Machining the faces of either the block or head retard cam timing slightly.
Italian pistons do not enjoy a great reputation for consistent machining.

Retarding timing means that the exhaust valve is not as far along the closing cycle as it should be at TDC and the exhaust cam has been striking the piston. In this case the intake has suffered more damage and it would have had slightly more clearance if the timing was slightly retarded.

The pistons are Italian and it is vitally important to measure them as well as clearances in any non-standard motor.

One could be generous and suggest that the Honda shop may not be experienced with old motors and may have expected new parts to drop straight in. After all they are not race engine builders.

Or one could take the opposite approach and suggest that if they don't know how to build a 30 year old motor, they should leave it alone.

You appear to be way more forgiving than I am. I would not take it back to a shop that has demonstrated a clear lack of knowledge and skill which is probably why I build all my own motors and why I hate to do it for others- it takes so much time to get everything dead right.

Just setting up the top end and checking clearances can take all day to build, check, strip, machine, build check strip. ... Repeat until it's perfect.

Good luck with them. I hope they take care of you.

[LOUD MOUSE]

Would ya bet that the cam chain was one tooth off???????????????. .............lm

FYI, I had another look at those couple of pics and both valves show clear signs of impact on their lower faces. In the picture, that is the upper/outer faces. there are signs of heavy and repeated impact with "something".

A couple of things to consider:
Machining the faces of either the block or head retard cam timing slightly.
Italian pistons do not enjoy a great reputation for consistent machining.

Retarding timing means that the exhaust valve is not as far along the closing cycle as it should be at TDC and the exhaust cam has been striking the piston. In this case the intake has suffered more damage and it would have had slightly more clearance if the timing was slightly retarded.

The pistons are Italian and it is vitally important to measure them as well as clearances in any non-standard motor.

One could be generous and suggest that the Honda shop may not be experienced with old motors and may have expected new parts to drop straight in. After all they are not race engine builders.

Or one could take the opposite approach and suggest that if they don't know how to build a 30 year old motor, they should leave it alone.

You appear to be way more forgiving than I am. I would not take it back to a shop that has demonstrated a clear lack of knowledge and skill which is probably why I build all my own motors and why I hate to do it for others- it takes so much time to get everything dead right.

Just setting up the top end and checking clearances can take all day to build, check, strip, machine, build check strip. ... Repeat until it's perfect.

Good luck with them. I hope they take care of you.

[MBellRacing]

Thanks for the input. I am no longer using the Italian race pistons. I am WAY over using non-stock parts where it counts. I went and bought new sleeves and pistons and will use those instead.

I am absolutely certain that the cam chain was on the correct tooth. I checked, re-checked, took a nap, then checked again to make sure it was correct.

I'll let you all know how it goes! Thanks for the help!

[LOUD MOUSE]

Sure makes one wonder what was happening in there for sure. ........lm

Thanks for the input. I am no longer using the Italian race pistons. I am WAY over using non-stock parts where it counts. I went and bought new sleeves and pistons and will use those instead.

I am absolutely certain that the cam chain was on the correct tooth. I checked, re-checked, took a nap, then checked again to make sure it was correct.

I'll let you all know how it goes! Thanks for the help!

[MBellRacing]

Hey everybody, thanks again for your help so far.

I've been out finishing up the race season this past weekend while my head and block, ready for STOCK pistons, was at an engine builder. These guys are very reputable, especially in the vintage racing world. They've been building vintage motors since before they were considered "vintage"!

Today, my builder reassembled the head and noted that the valves were VERY poor pieces of work. He said one of the machined grooves broke off and was therefore the point of failure for my engine. These were Apex Cycle valves. He highly recommended that I never use these again. He said they look like "China valves", commenting more on their material than their place of manufacture.

Anyway, I plan on cleaning out all the metallic milkshake out of my motor tonight, pick up the new parts tomorrow, and reassemble over the next few days. I'm going to double check the timing with a timing wheel-- can anyone tell me the points of opening of the different valves in degrees?