Giving a Bezoat a Second Chance

[DeanFHobart]

The top red boat appears to be a Bezoats also… Correct?

[Albert]

Was in the neighbourhood today where the boat is stored…unfortunately it was snowing so we left it on the rack. Lots of work to do in the next month though.
E97FD666-640A-4D4F-8F9D-4515F6F5DA9C.jpeg

[Albert]

Need one of those cylinders with a degree.
You know a graduated one!



I’ll show myself out.

[ZUL8TR]

No spec on CC's for just the head chamber. To measure with head + gasket bolted on block and head horizontal is not messy but must have accurate way to measure CC's of liquid you put in and remove all trapped air.

[Albert]

Tom Johnston may be able to clean up that cylinder head.

I would imagine he could, I’ve been told through the grapevine that he’s quite a competent machinist.
A skilled mill operator could make it perfect again. A good welder could even build up the dome with minimal warpage and then have it re-machined back up to original.

I am not a machinist, and I’m a lousy welder, but I think my tool will grind the band smooth, then a caliper can ensure both chambers are quite close and then measuring the volume of the heads as Pete pointed out will make sure the cylinders are balanced and legal.

I could have sent this head off to get fixed for 3-500$ Canadian. (200-350usd) but I wouldn’t learn much, and I wouldn’t have a tool to help me fix this problem if I need it. Or to help a friend fix a head in a pinch.

I do have a friend whose a bit of a cad/cnc nerd I’m sure he could make me a new head. But dropping 2k on a billet head wasn’t really in the cards for me right now.

[deeougee]

That’s ok Mike, we can handle it in house, we have the technology. It’s actually an easy fix. We could even make them scratch if we really wanted too. The head dimension rule delete helped significantly with that but we could do with or without the dimension rule.

[pav225]

Tom Johnston may be able to clean up that cylinder head.

[Albert]

Just re-read it appears it must be measured on the motor with motor at tdc…sounds messy.
I assumed there would be a spec for the head chamber itself.

[Albert]

I was clearly looking at the wrong spot in the manual (will print a paper copy and give it a good read at some point).
Good to have the info as I have two heads to fix.
I can just bolt the head to a piece of flat plate and fill with a measured syringe with oil? Unless there’s an easier way.

I spend half an hour working on that head last night. It’s slow going by hand with valve lapping compound but it’s doing a nice job.

[ZUL8TR]

Luc
Min CCs in Tech manual pg 84 is 18cc for 14mm plug head and 18.5cc for 18mm plug head with cc measured per manual specs pg 11 and 12. Head bolted on with head gasket and liquid used filled to top of plug opening. Not sure what you mean there is no min cc for cylinder head?

https://www.apba.org/documents/12505...nual%20(1).pdf
Pete

[Albert]

51753BCF-F06E-49D6-8A56-60DD43871401.jpeg OK,
So since no one seems to want to recast and machine heads for an 80 and replacement heads seem scarce it was time to get creative.
Step one consult the manual:

27. It is legal to re-machine squish band area to the following measurement: angle 15° ± 2°, 2.350 ± 0.015. No changes may be made to the combustion chamber. There must be a visible ledge surrounding the squish band.


I assume there is also a minimum cc for cylinder head but I don't see it in the apba manual.
Regardless my squish band needed love and my by hand grinding job last year left a lot to be desired.

If only I had something like this die to work in some valve grinding compound to repair the squish band without putting it on a lathe or mill.

[ZUL8TR]

Luc
You are welcome. March on with the work it will be worth it and a great accomplishment. I look back at all the people along the way that helped me and pass on what I can to others.
Have a good day
Pete

[Albert]

Thanks for the words of encouragement Pete. I know this is stuff some experienced racers have been going through for many years. But it’s new to me, and I figure it may answer some questions for other rookies along the way.

Maybe the lesson to be learned here is start with good gear. Or don’t hack a motor together. Or don’t be a mechanical masochist. Or that you can start with garbage and end up with a pretty nice set up if you have helpful friends, are willing to read a lot and don’t place value on your own time invested in a project.

[ZUL8TR]

Keep us posted with pics on your progress. This is a great thread.

[Albert]

Your right once again its Lucas...not sure what I was thinking there.