bbc gas ported pistons

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prairiehotrodder
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bbc gas ported pistons

Post by prairiehotrodder » Wed Mar 14, 2018 12:35 pm

So I just brought in a set of wiseco pistons for a customer. The motor is a 565 BBC with 10.8 CR and nitrous. They were supposed to have vertical gas ports but they don't. The customer already has a set of hellfire rings. Is there any big problem with just using the pistons as they are ? Or should I ship them back (big pain because i'm in Canada). The part number is K0245A100
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Re: bbc gas ported pistons

Post by SupStk » Wed Mar 14, 2018 12:55 pm

Pistons I order with gas ports have zero vertical clearance on the ring lands. If yours has over .0015", I'd say you can use them as is.
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Re: bbc gas ported pistons

Post by prairiehotrodder » Wed Mar 14, 2018 2:30 pm

so that's measured with a feeler gage between the ring and the land ?
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Re: bbc gas ported pistons

Post by SupStk » Wed Mar 14, 2018 5:00 pm

Yep
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Re: bbc gas ported pistons

Post by engineguyBill » Wed Mar 14, 2018 6:06 pm

SupStk wrote:
Wed Mar 14, 2018 12:55 pm
Pistons I order with gas ports have zero vertical clearance on the ring lands.
Wow, what is your reasoning for ordering pistons with zero ring clearance for gas port applications?
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Re: bbc gas ported pistons

Post by SupStk » Wed Mar 14, 2018 10:54 pm

engineguyBill wrote:
Wed Mar 14, 2018 6:06 pm
SupStk wrote:
Wed Mar 14, 2018 12:55 pm
Pistons I order with gas ports have zero vertical clearance on the ring lands.
Wow, what is your reasoning for ordering pistons with zero ring clearance for gas port applications?
Way less chance for flutter. Ability to lap rings.
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Re: bbc gas ported pistons

Post by MadBill » Wed Mar 14, 2018 11:01 pm

Were the rings specced out for gas ports? If so, the tension might be on the low side for an un-ported application.(and if they weren't, the gas ports would have been less effective.)
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Re: bbc gas ported pistons

Post by engineguyBill » Thu Mar 15, 2018 12:35 pm

SupStk wrote:
Wed Mar 14, 2018 10:54 pm
engineguyBill wrote:
Wed Mar 14, 2018 6:06 pm
SupStk wrote:
Wed Mar 14, 2018 12:55 pm
Pistons I order with gas ports have zero vertical clearance on the ring lands.
Wow, what is your reasoning for ordering pistons with zero ring clearance for gas port applications?
Way less chance for flutter. Ability to lap rings.
Lapping rings has pretty much gone the way of points and condensers . . . . . . .
Current high performance pistons have, for the most part, very consistent groove dimensions and flatness. High performance rings are also spot-on as far as dimensions are concerned, therefore you can order rings/pistons with .0010" (or less) side clearance and rest assured that the clearance will be consistent throughout the circumference of the ring/groove. It is actually possible to do more harm than good when lapping rings. Yeah, I know - some guys still do it.
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Re: bbc gas ported pistons

Post by engineguyBill » Thu Mar 15, 2018 12:38 pm

MadBill wrote:
Wed Mar 14, 2018 11:01 pm
Were the rings specced out for gas ports? If so, the tension might be on the low side for an un-ported application.(and if they weren't, the gas ports would have been less effective.)
Generally speaking, rings used for gas port application will be thin axial width along with thin radial thickness, which will result in proper tension for the gas ports to work properly.
Bill

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Re: bbc gas ported pistons

Post by MadBill » Thu Mar 15, 2018 1:44 pm

Yes, so it will be important to verify if it's just that the gas ports were omitted or if the groove depths are also incorrect for the customer's rings.

If nothing else, that Wiseco p.n. is cataloged as having gas ports, so a credit would be in order for the option price.
Felix, qui potuit rerum cognscere causas.

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Re: bbc gas ported pistons

Post by prairiehotrodder » Fri Mar 16, 2018 1:19 pm

thanks for the help guys. I'm returning them. My customer already has rings that are made for gas ported pistons.
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