Topic: 836 high comp pistons and mystery cam

[lofijsc]

Hello,

I'm hoping somebody could hold my hand through assembling these parts I have accumulated. I have:

-72 bottom end
-sandcast cylinder block bored out to 836
-vintage high compression pistons (markings dremeled off)
-77/78K cylinder head
-mystery cam that appears to be a stock casting marked "R8" that is ground down .10 inch

In theory, can these parts safely go together? Can someone help me with the gasket configuration?

Thanks!

[540nova]

If it was me, I'd go with a known,  new cam, especially if you're using HC pistons.

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[Jerry Rxman Griffin aka MuthaF'er]

Are there any other markings on the cam? on the ends? Post some pictures of the cam and pistons.

[754]

Not the best combo of head and cylinder.
First find out if your bores are good, you can still go 850 , or pick up a late block, to go with that head.

[lofijsc]

Here are the markings on the cam

[lofijsc]

My machinist checked the bores and honed them.

[lofijsc]

Pistons

[754]

Some pistons easy to get rings, some not.. Some were overly high compression....

[754]

 I think the grinding is weight matching, piston appear to have thick heavy skirts..going off the pic.

[MRieck]

Heavy, clunky old pistons. Pins look a bit scorched. Get some modern pieces brother. i have cylinders if you need one. Frank is correct about the mixing and matching.

[lofijsc]

Can you elaborate on the problems with this combo of head and block. I thought they where definitely incompatible but another member on here told me they can go together with the right gaskets. I'd like to understand the problem better, thanks

[754]

You may have to trim dowels or rubbers, the late heads had better sealing, but part of what they used fit into both cylinder and head.

[BPellerine]

the parts will go together,but it may not be the best combination,the pistons you show take the one piece oil ring,modern rings may not fit,so you would have to get rings custom from total seal,and they are not cheap,if you are on a budget there are cheap 836 kits on ebay,high compression is not for everyone on the street.bill

[lofijsc]

I have a new set of modern rings that my Machinest says he can turn the ring groove to fit.

[Medyo Bastos]

are there any markings on the outsides of the pistons close to the clips? or, on the inside of the crowns?


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[754]

The other thing, pistons are now run tighter, how much clearance you got...most like to use 3pce oil rings.

[PeWe]

Cam marking is LF 1?  Not a Honda cam, right?
Measured the cam like lift, duration?

Any other markings ahere the sprocket is bolted, edge of the ears and under the washer on other side?