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dropped a seat...
Posted by: 427rs ()
Date: May 15, 2017 06:45PM

Have a 65 corsa conv... Wolf carbs, ball bearing linkage, 280 cam with seths distributer, wires and coil. Bought lowered springs and kyb shocks from Corvair Motorsports years ago before they closed... Running 18x9s on the back with 18x7s front... Running a Camaro front spoiler and have the corvette rear strut rods... Just aligned it with a 2x4 and 24inch bubble level as I was wearing out the inside of the tires front and rear... I was taking a nice spin yesterday when I developed a skip... was hoping it was just carbon in a valve but did a compression and leakdown on the dreaded #5 and sure enough no compression... Pulled the head and the intake seat and valve are sticking out an eighth of an inch... Bought a set of worked over heads from Starr Cooke on ebay and ordered headers and gaskets from Clarks... Was lucky there was no damage to the piston which appears to standard and not to carboned up... The cylinders pulled out a little from the block when pulling the head will I need to pull the rods and jugs and replace the gaskets at the case or will they be ok just pushing them back in? Will post how well the heads and ultimate exhaust wake up the engine...

Brian C.
Horseheads, NY

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Re: dropped a seat...
Posted by: MattNall ()
Date: May 15, 2017 06:47PM

If not torn... should be fine





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Re: dropped a seat...
Posted by: Scott V ()
Date: May 15, 2017 07:29PM

427rs Wrote:
-------------------------------------------------------
> did a compression and leakdown on
> the dreaded #5 and sure enough no compression...
> Pulled the head and the intake seat and valve are
> sticking out an eighth of an inch...

> Bought a set
> of worked over heads from Starr Cooke

do the heads you got from starr have stock valve seats?

-Scott V.

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Re: dropped a seat...
Posted by: 427rs ()
Date: May 15, 2017 07:31PM

He stated that they are staked which I know was what they did in the day...

Brian C.

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Re: dropped a seat...
Posted by: Scott V ()
Date: May 15, 2017 07:35PM

yea........stakeing was done in the day.....& that didnt work too good to keep the seats in the head.

sorry to say.

-Scott V.

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Re: dropped a seat...
Posted by: 427rs ()
Date: May 15, 2017 07:48PM

I know he has a good reputation and has done many heads through the years... The heads have had material taken off the cooling fins to help and I have sealed off the heater hole in the shroud by #5 which should help... Just have to wait and see...

Brian c.

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Re: dropped a seat...
Posted by: Scott V ()
Date: May 15, 2017 08:58PM

not trying to make problems.......but taking material off the cooling fins make the head run hotter......not cooler.

if you mean that the heads were deflashed.......the cooling passages unblocked/opened up......thats a good thing. dont think i have seen any ebay stuff from starr that says he deflashed the heads.


sealing off the heater hole in the shroud by #5 is a good thing. if that was open.....thats a good reason why the seat dropped.

-Scott V.

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Re: dropped a seat...
Posted by: Chilly Willy ()
Date: May 15, 2017 09:18PM

I question the staking. Seems like a short term fix. From the pics it looks like it could lead to hot spots.



Will
Northern California

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Re: dropped a seat...
Posted by: BobV66Vair ()
Date: May 15, 2017 10:46PM

Staking = Bad. Not something that makes anything better. Used to be done and is still done but it's a bad idea passed down for decades. Nothing staking can do to prevent future seat failure. Plus you put protruding metal in the combustion chamber. All that can do is lead to detonation or lead to oval seats if you hit it hard enough. Put the right valve seats in and watch for heat issues.

Bob Vinnacombe
Sandy, Oregon
1965 Corsa 140 stock
1966 Monza Soon to be race car
1968 Monza Parts for now

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Re: dropped a seat...
Posted by: 427rs ()
Date: May 16, 2017 03:30AM

Says he took .130 off head gasket seating area and .190 off fins... he flowed chambers and exhaust ports, new spings set to 115pds with new keepers with SS exhaust tubes... I know he has been big in buggies in Cali for years so I figured I would give a set of his heads a try...

Brian C.

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Re: dropped a seat...
Posted by: Ratt643 ()
Date: May 16, 2017 03:51AM

Put deep valve seats in, you will be much better off.


1964 Monza Coupe

Maryville, TN
U.S. 129 The"Tail Of The Dragon"

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Re: dropped a seat...
Posted by: texas yenko dude ()
Date: May 16, 2017 04:56AM

#1. All stakeing does is help loosen up seats. Deep, high press fit seats is what you need.

2. If the heads are cut .130, I hope you have stock in VP, Sunoco, or the like. You are going to be needing to be burning 110 since you will most likely have 38-41cc chambers. Compression adds heat, heat adds expansion, and expansion is hell on valve seats.

3. Yes, Starr has a reputation. I'm going to stop right there.....................

Texas YENKO Dude
YS-070
YS-199
YS-320
Southeast of Disorder


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Re: dropped a seat...
Posted by: gnvair ()
Date: May 16, 2017 05:29AM

Does Starr Cooke have a flow bench for "flowing" heads?

Lee J
Southern New Jersey near Philly.
1966 Corsa 180/4 speed
1969 Monza convertible 140/4 speed

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Re: dropped a seat...
Posted by: JimBrandberg ()
Date: May 16, 2017 05:46AM

I certainly agree that staking has fallen out of favor and seems inelegant. Having said that, we lost valve seats in Ice Racer heads regularly back in the day and staking alleviated that. I might have trouble bringing myself to do it but I can't absolutely say it's a bad thing.
Even with double .052 copper head gaskets you're probably not getting back to 9/1. Is .110 cutting into the squish chamber as well, getting close to the spark plug holes? Anyone care to talk about Singh Groove? Anyone ever triple stacked copper head gaskets?
I got some stuff from Starr Cooke and have talked to him on the phone. My experience was good.
Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: dropped a seat...
Posted by: Scott V ()
Date: May 16, 2017 06:55AM

427rs Wrote:
-------------------------------------------------------
> Says he took .130 off head gasket seating area and
> .190 off fins...

the fins are like .08 thick & around .2 between fins. so your heads are missing 1 cooling fin now?

-Scott V.

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Re: dropped a seat...
Posted by: TerribleTed ()
Date: May 16, 2017 08:34AM

.130 machined off sounds like a lot. Are you sure it is not .013? I just had a set of head done that had some moderate head gasket grooving. My machinist says he took off 15-20 thousandths so .015-.020 getting them flat.

Avid Corvair hobbiest since 1984. Have personally restored 20 or more Vairs a number of them ground up.

Located in the Atlanta Georgia area.

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Edited 1 time(s). Last edit at 05/16/2017 08:35AM by TerribleTed.

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Re: dropped a seat...
Posted by: BobV66Vair ()
Date: May 16, 2017 09:02AM

JimBrandberg Wrote:
-------------------------------------------------------
Anyone care to talk about
> Singh Groove? Anyone ever triple stacked copper
> head gaskets?

> Jim Brandberg
> Isanti, MN
> CorvairRepair.com


You had to bring that up! Honestly I had no idea what it is so I checked around. Lots of anti big-auto talk and global warming stuff but other than that, just anecdotal reports. Their dyno tests are questionable since they did not post the actual process details or how they blind tested it. Hot Rod says they do not add any performance. So, who are we to believe? One would think that the big auto guys would look seriously at it to help meet CAFE standards. I suspect their engineers looked at it extensively and saw no reason for it to work as promoted. But that's just my opinion.

Increased turbulence in the CC sounds like a good thing but if a few scratches help, why not an engineered series of grooves? The HEMI heads are supposed to give more HP too because they increase gas turbulence. I am not sure that's why but it did sell a lot of engines. They went the way of the dinosaur but recently came back. Another marketing ploy? The sophistication of modern engines seems to be a long way from the 60's or adding some groves. My take away is that it's a nice idea but not really something that would make a difference. IMHO.

I do appreciate learning something new though! Thanks for that.

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Re: dropped a seat...
Posted by: JimBrandberg ()
Date: May 16, 2017 10:04AM

What the Singh Groove proponets say is that you can run higher compression ratios without pinging. So I suppose the higher performance would come from the increased compression ratio and not the groove per se. The jury is still deliberating but I would like to hear testimony.
I believe I started a thread here on Singh Groove a year or two ago but it didn't gather much steam.
Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: dropped a seat...
Posted by: MattNall ()
Date: May 16, 2017 10:25AM

I believe Ken Hand is Running the heads with the groove.





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: dropped a seat...
Posted by: RobertC ()
Date: May 16, 2017 05:07PM

I do not know why it can be stated that staked valve seats caused the seats to become loose.

Do not know of any dropped valve seats occurring shortly after the seats were staked. But, my population data is not large.

But, I have seen a good number of techniques applied to staking seats.

Do realize that when one seat drops that the other seats are prone to dropping if something is not done (just replace the one dropped seat and not the others).

Basically, seat failure is related to heat cycles / run time (and hot / cold air resulting from rapidly opening / closing the butterflies aiding the process) - with engines that have been overheated multiple times more prone to seat failure than other engines that have not been overheated.

Running an engine lean (hotter) probably is a factor, also.

But, in the end - with enough heat cycles / run time, a seat will come out - staked or not staked.

Interesting comments on having heads re heat-treated.

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