[Healeys] Pistons

[WILLIAM B LAWRENCE]

Forged pistons are desirable for racing engines or those that are going to be operated at or above the manufacturer's rev limits. If you are going to be operating in the normal range for normal driving they may not provide an advantage. Burned, melted or holed pistons are more often related to combustion chamber conditions that cause excess heat or impede heat transfer. Proper ignition timing, air/fuel ratio and a reasonable compression ratio are critical.


After I holed two pistons I found that the cylinder head I had been using had been shaved by over 0.040" the combustion chambers were cut down to about 50cc and the compression ratio may have been over 10:1. The engine had even pinged on premium fuel and that or the imprecise timing or a combination of both had eventually caused the piston damage. It would not have mattered if I had spent $1000 on pistons.


Bill Lawrence

BN!#554

________________________________
From: Healeys <healeys-bounces at autox.team.net> on behalf of goldengt <goldengt at cal.net>
Sent: Tuesday, November 15, 2016 12:03:09 AM
To: Bob Spidell; healeys
Subject: Re: [Healeys] Pistons

I think my JE forged was a good choice after two rebuilds due to melted pistons over the years.
Ken Freese



Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Bob Spidell <bspidell at comcast.net>
Date: 11/14/16 11:47 AM (GMT-08:00)
To: healeys <healeys at autox.team.net>
Subject: [Healeys] Pistons

Thinking about which pistons to buy form my BJ8 rebuild.  'Generic' sets run about $400 and look OK--as if you can tell by looking at pictures--and the top-of the line appear to be Denis Welch's forged pistons (at nearly a grand$).  Are the forged ones worth it?  Also, most 'stock' sets are 5-riing, and the DWR are 3.  Obviously, the 3-ring would have less friction/drag than the 5-ring, but would the difference be significant in a mostly stock street car?

Also, any recommendations on brands or suppliers?

TIA,
Bob

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Bob Spidell - San Jose, CA

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