[Fot] TR6 Piston / Head Clearance

[Steve Yott]

I doubt that your .030 squish would cause the rattling as you describe.  The deflection caused by the crank, rod and piston in order to hit the head at .030 would be way up in the rpm’s like 8000!

 

Did the rattling go away after all the parts warmed up and oil was well disbursed or is it still rattling?  My first guess would be either the engine was not pre-oiled or you have loose piston pin bushings….  Were the rods rebuilt with new bushings fitted to about .0003?  

 

Steve Yott

 

From: Fot [mailto:fot-bounces at autox.team.net] On Behalf Of Robert Lang
Sent: Wednesday, May 25, 2016 11:29 AM
To: FOT List
Subject: Re: [Fot] TR6 Piston / Head Clearance

 

Hi,

 

Where I was going with the query was this: I had a late block "decked" with the intent of making the deck flat. The machinist took of .032 to accomplish the goal. With a head gasket installed and the head torqued, the clearance in the squish area is .030.

I had initially wanted only about .025 removed, but we had to shave an extra .007 to get rid of the fire ring cuts.

On initial startup, the motor sounded like it might be "rattling" and I'm trying to figure out why.

When I used a stethescope on the block, everything sounds okay - no rapping and the valve train sounds "normal" and there were no weird sounds coming from the crank.

I guess where I'm going with this is: if piston / head clearance is too tight, I'll see some sort of indication on the piston, right?

TIA for any sage advice.

This is my first experience "decking" a block. I'd like to get it right, I don't have the resources to start a new block from scratch.

Regards,

Bob Lang

 

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