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Re: Custom pistons
Posted by: JimBrandberg ()
Date: October 24, 2020 05:49AM

Two YHs, now there's a purist, I love it. It sounds like Smitty does a lot of cool stuff in his little garage.

As a general rule of thumb I've always thought that it would be difficult or impossible to get rid of the heat when running a Corvair turbo for a long time in competition. It's interesting to consider that it may not necessarily be the case. That's one thing cool about Vintage Racing, it can cover a broader spectrum. I look forward to reading about it, please update about what magazine it can be found in. Maybe a magazine like that is worth subscribing to.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Custom pistons
Posted by: 63turbo ()
Date: October 24, 2020 08:40AM

Frank DuVal Wrote:
-------------------------------------------------------
> Smitty ran a turbo fed by two YHs in road racing. Have no clue about the innards. He held that close. grinning smiley

There was a write up in one of the Corsa Communique's on Smitty's twin YH set-up,
and I believe it was written by the late Bob Helt. With that set-up, Smitty was running 15psi of boost, and ended up running a more modern, more efficient turbo with it, which is extremely helpful with head temperatures, both because the more efficient compressor doesnt heat the inlet air as much, and doesnt produce as much exhaust backpressure to produce the same boost as any of the stock Corvair turbo's.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Custom pistons
Posted by: edconnolly ()
Date: October 24, 2020 10:58AM

If the carburetor is limited to a single barrel but does not have to be the YH, the 2-in. SU is a good choice.

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Re: Custom pistons
Posted by: cnicol ()
Date: October 24, 2020 01:10PM

I have a set of dished pistons in one of my Corvair engines. They're new, it's never been run and I was thinking of switching them out to bring the compression up. What's the maximum oversize allowed by your class rules?

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
60 Monza coupe (sold, sniff sniff)
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: Custom pistons
Posted by: 63turbo ()
Date: October 25, 2020 09:32AM

Actually, the compression ratio on any of the stock turbo heads is much lower than advertised... something like 7.5 to 7.8. The compression does not need to be lowered further, it is a matter of better ignition timing, and all else being equal, it is far better to keep the compression ratio up and the ignition timing weak than it is to lower the compression ratio, and then have to advance the timing enough to make the same power, as the engine will run hotter and will be increasing the chances for detonation, simply because theres more time for a bad combustion event to happen. The stock turbo timing is WEIRD and doesnt work that great, and is mostly wrong. I dont know what the rules allow for vintage racing but if the stock turbo distributor has to be used, it would be a REAL fine idea to at least re- curve that thing to give something closer to good timing at peak boost.

26 degrees total at 4k and 10 psi is perfect and safe, although the engine will probably want more timing if the revs are higher at the same boost.

v8vair mentioned a turbo corvair running at Sebring in the 60's, heres a link with pictures of that car.
[corvaircenter.com]

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car






Edited 1 time(s). Last edit at 10/25/2020 09:36AM by 63turbo.

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Re: Custom pistons
Posted by: Coupea ()
Date: October 26, 2020 12:50PM

The maximum overbore allowed is 0.03'', but i'd rather stay at the standard size for maximum strenght and a possibility to overbore later if/when an accident happens. My boss just gave me a Bosch distributor bench and i am quite sure it will be working overtime before i'm happy with the results. The YH has been enlarged quite a lot as the rules do allow any sort of machining as long as material isn't added. Because any sort of boost control hasn't been homologated my only option to control the boost is to port a couple of exhaust housings and cut down the turbine wheel as needed. Getting the engine tuned, stay together and be drivable is not going to be easy but fortunately we have a rolling road at work so i have unlimited tuning time when i get to that point. The magazine i mentioned earlier is a Finnish old car magazine Mobilisti. (www.mobilisti.fi) unfortunately only in Finnish at the moment.
Jonni

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Re: Custom pistons
Posted by: v8vair ()
Date: October 27, 2020 06:56AM

Are you allowed to run Race Fuel, 110 ?? if so that will really help keep detonation under control. Personal experience on my Spyder with race gas is a delight !

1965 Crown V8 Racer
1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1979 Mazda RX7

Mike Levine

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Re: Custom pistons
Posted by: American Mel ()
Date: October 27, 2020 11:16AM

From the first page . . . .
"Coupea Wrote:
-------------------------------------------------------
> Thank you all for the interest. Unfortunately i won't be able to tell much about the advance of the project until the car is finished as one of my sponsors is a local magazine. There will be a detailed article about the car when i get to the point of testing so until then i can't post much about the project (2021/2022). As for the cooling the fan is free and i will use the Nash Fan, the heads will be deflashed , intake air for the engine will come from behind of the front axle trough shift tube/heater duct tunnel and a large additional oil cooler will be used.The fuel has to be pump gas but any commercially available additive is allowed. The car will run against 400hp Mustangs and Falcons but has a huge advantage because the homologation weight is really low compared to the Fords and 8'' wide wheels are also homologated (Falcons have 5.5'' and Mustangs 7''). I now it won't be easy to make the car reliable and fast but i'we always enjoyed a challenge.
> Jonni"

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, 80hp, PG
'62 Monza Wagon, 4spd.
'63 Spyder,
'65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dually, approaching 400K
'03 Honda Del Sol
17'Terry
[corvaircenter.com]

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Re: Custom pistons
Posted by: MattNall ()
Date: October 27, 2020 11:28AM

Does your sponsor Have good fund for Dyno time? You'll need several sessions..and at least a couple builds to determine what internals work best.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Custom pistons
Posted by: v8vair ()
Date: October 27, 2020 12:00PM

Pump gas, Air/oil cooling, no boost control other than stock is hard for a street car let alone a racer. Not sure its doable sadly to say.

1965 Crown V8 Racer
1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1979 Mazda RX7

Mike Levine

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Re: Custom pistons
Posted by: American Mel ()
Date: October 27, 2020 01:33PM

Matt,
"Coupea Wrote:
-------------------------------------------------------
> The maximum overbore allowed is 0.03'', but i'd rather stay at the standard size for maximum strenght and a possibility to overbore later if/when an accident happens. My boss just gave me a Bosch distributor bench and i am quite sure it will be working overtime before i'm happy with the results. The YH has been enlarged quite a lot as the rules do allow any sort of machining as long as material isn't added. Because any sort of boost control hasn't been homologated my only option to control the boost is to port a couple of exhaust housings and cut down the turbine wheel as needed. Getting the engine tuned, stay together and be drivable is not going to be easy but fortunately we have a rolling road at work so i have unlimited tuning time when i get to that point. The magazine i mentioned earlier is a Finnish old car magazine Mobilisti. (www.mobilisti.fi) unfortunately only in Finnish at the moment.
> Jonni"


Finnish, for Dyno ? ? ?

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza
Have had; '61 Monza coupe, 80hp, PG
'62 Monza Wagon, 4spd.
'63 Spyder,
'65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dually, approaching 400K
'03 Honda Del Sol
17'Terry
[corvaircenter.com]

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Re: Custom pistons
Posted by: Coupea ()
Date: October 27, 2020 01:56PM

I work in a company that has a rolling road dyno so my dyno time is close to unlimited.
Jonni

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Re: Custom pistons
Posted by: goatsnvairs ()
Date: October 29, 2020 05:14PM

If you can only run a 1 barrel, consider a mikuni 45mm slide carb.. Mine works great on my turbo.

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Re: Custom pistons
Date: October 30, 2020 04:57AM

Hey jonni youre located in Finnland?
We have the same idea and a racecar here in Germany..but no time to start now.

We also will race Appendix K.
But naturally Aspirated..like the Stingers.

If you want some serious Information to build a turbo Charge engine here in Europa than call Derichs Rennwagen.
The Boss passt away a few year ago.
He was a Mechanics leader in Formula one in the 80's and than had a Racecar Shop Business.
He drive all of the vintage race in europe mostly known for his perfekt build Mustangs.

Than one He dicided to build a corvair racecar with his knowledge.

We sadly missed to buy the car.
But the Mechanik Who was with the Boss on working on the car is still available.

I called.Mrs.Derichs an she was very friendly.
I have copys of the FIA Wagenpass.documenta if you Are Interested..

Greets Fred.
See US sometimes on the Track..
Iam really love the idea of racing Corvairs against the Standard Seen cars here in europe

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Re: Custom pistons
Date: October 30, 2020 05:04AM

The 97 is ours (RED)
the other Derichs.
The car is now located in France.
And has New license FIA an street legal.

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Re: Custom pistons
Date: October 30, 2020 05:06AM

Good luck.
Would be nice to share the Corvair enthusiasm..and FIA expiriences..

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Re: Custom pistons
Date: October 30, 2020 05:14AM

There is an Artikel in a Magazine about Derichs Corvair.
A Magazine with in is for sale at present in German Ebay.

One thing.
You have to use a corvair Corsa model because monza an 500 700 Are not homologized..
I called FIA Headquarter in Paris about that..

Maybe you find a way but thats what the told me.
Again good luck.

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Re: Custom pistons
Posted by: Coupea ()
Date: October 30, 2020 05:41AM

Here's the current situation of the car. It is an original Corsa. I would be more than interested in the FIA passport of the German car.I have seen pictures of it and knew that it ended up in France, but that's all i know. Current FIA rules allow replicas and making lesser models per speed model specs (Cooper Minis, Lotus Cortinas, Shelby Mustangs ans so on) this change of rules happened around 2005.And yes i do live in Finland.

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Re: Custom pistons
Posted by: JimBrandberg ()
Date: October 30, 2020 07:16AM

Beautiful car. Everyone but me seem to have cars that are too nice to race.

It looks like they're getting ready to push it off the cart. What language would the be cursing in? I notice in-car Rally videos where the F-word seems to be multi-lingual.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Custom pistons
Posted by: Coupea ()
Date: October 30, 2020 07:41AM

Perkele would be the correct curse in finnish.

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