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2019 Rules Thread
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TOPIC: 2019 Rules Thread

Re: 2019 Rules Thread 5 years, 11 months ago #22173

while I appreciate your trying to keep the series true to its nature I also respectfully disagree that we are trying to change this into a biggest checkbook series. I would argue that I have what is probably the most inexpensively built/eye on the $$ car in the series. The only new parts on my car are the fluids and seat belts. Nearly everything else is second hand/cast off/hand me downs. SO if I have to go thru 3 engines/parts cars to assemble the proper parts to build an engine then that's not cost effective to me. IF as has been suggested a set of "to factory spec" pistons can be sourced in the aftermarket for what im paying for a unknown used engine then I feel it should be at least investigated. We don't have to do it for this year but it should at least be looked at.
I love this series and the guys I race with. I wouldn't be racing if not for them so I don't plan to go anywhere.
Michael Morris

Re: 2019 Rules Thread 5 years, 11 months ago #22174

  • Manuel_M
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Would these pistons be in 3 tolerance groups like the oem versions (0,1,2)? All 100mm but +/- several thou. Or would they be looser / tighter depending on the block?

Re: 2019 Rules Thread 5 years, 11 months ago #22175

I would support after market pistons. Having just rebuilt my engine I had a heck of a time finding either an 88 engine or pistons. As long as there is no performance advantage I don't see the harm.

Re: 2019 Rules Thread 5 years, 11 months ago #22176

  • rd7839
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if there is no performance advantage why did you look for 88 pistons? wht not 84 pistons?



edit:Sorry, that message sounds snotty, I didn't mean it that way!
Last Edit: 5 years, 11 months ago by rd7839.

Re: 2019 Rules Thread 5 years, 11 months ago #22177

  • AgRacer
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rd7839 wrote:
if there is no performance advantage why did you look for 88 pistons? wht not 84 pistons?


He means no performance advantage in an aftermarket piston over an OEM used piston.

***Cue the "you don't need high compression pistons to win" argument.***

As stated by plenty of others previously, there is an advantage to 10.2:1 pistons over the 9.5:1 pistons. No you don't need them to win but the higher CR piston is a superior part. We are still racing after all so racers are going to seek out the best parts to compete with. You CAN also win without an LSD. You CAN also win with a tall 5th.

If our goal is to make this class about equal racing, then we need to allow all racers equal access to all of the parts.

Just did the quick check of my local big city craigslist (Raleigh, NC) and even upped the min price to $1000: Zero parts car results. Expanded to Eastern NC: only one parts car and it had a bad ENGINE...

I searched ebay and Car-Part.com for 1988 10.2:1 pistons and found zero results.

Ebay has 4 sets of used pistons available with rods, all 9.5:1 CR with an average price of $163. (High $200 for RARST rods, low $150)

A new set of piston rings alone are $150 in addition to the cost of whatever used pistons you source. Using the average ebay price that makes it $313 if you have to source pistons for an engine build. This price will only go up if you want to use 10.2:1 CR pistons.

Wossner pistons are priced at $640 WITH rings.

Grand total price difference between used 9.5:1 pistons and new 10.2:1 pistons of about $327.

How much of a premium does a Dirks engine equipped car fetch? One quick ad I found was a car going for $10k so that engine builder markup is already happening. Nobody had a problem with Dirks building quality engines for racers. Why didn't he just throw junkyard engines into every car that came into his shop?
J. Stanley
NASA-SE Region 944 Spec Series Director
Yellow #60

Re: 2019 Rules Thread 5 years, 11 months ago #22178

  • tcomeau
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Good question, Manuel. Porsche went for 100 mm in the cylinders. If the bore came out to 100 mm exactly, use group 0 piston.

Group 0 = 99.980 piston for 100.000 mm bore
Group 1 = 99.990 piston for 100.010 mm
Group 2 = 100.000 piston for 100.020 mm

I haven't yet tried using ,say, group 2 pistons in a group 1 block to tighten things up. Haven't needed to. So would the aftermarket proposed piston come in 3 diameters or would we all have to overbore our blocks?



Dead horse, I don't know who you are (No name in signature), but glad to hear you're sticking around.

You don't need an 88 block OR 88 pistons to have a competitive engine. We've proved that. It's just a different way of getting to the same goal. You don't need an 88 DME. The F9Tech DME is better and should be more reliable.

I'm going to publish a list of regular parts suppliers around the country, somehow. Nobody in the US should be wanting for parts. Don't buy an engine unless the head is removed and the bores are inspected for scoring. As long as the bores are smooth, you should be ok with fresh stock Goetze piston rings. We've proved that also. Look for the engines out of automatic cars since these engines don't get rev'd up much before they shift into a higher gear. STILL insist on seeing the cylinder walls before buying. Don't settle for, "it was running when pulled from car." I've seen big scoring on torn down engines and the engine was still running without smoke plumes out the tail pipe.
Tim Comeau
SoCal 944 Spec #22 since Feb 2003.
Let's keep building it!
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