cameo

Anyone have a pic of an original 10.5 piston for a 1957? curious what the dome looks like.

verle

No 57 had a domed piston, flat four valve relief pistons only.

cameo

so the 10.5 was flat and the 9.0 was dished?

MikeM

All the fuel injected 283's including the '57 with solid lifters and also including those very few '61 hydraulic cammed 275 hp FI engines used the domed pistons which are very similar to the factory domed 327/350 pistons. They had two valve reliefs which meant there was a left and right bank piston

All the rest of the 283's got flat top pistons with four valve reliefs and the pistons were interchangable from right to left bank because of these two features.

1snake

This a link to a set on E-Bay that shows a good picture on the piston top. It saves me a trip to the garage as I have a NOS set waiting to go in a motor.

http://cgi.ebay.com/ebaymotors/Parts...=p4506.c0.m245

Jim

john neas

Verle
The 57 283 HP Corvette and Car had domed pistons. I have two engines with 57-60 type pistons. 61 had a fuller dome similar to the 62-65 FI dome. Come by tomorrow at 11 with a camera and take pictures of NOS 61 and used 57s. Free Goldies lunch.
Regards

john neas

The ebay picture shows a piston similar to the 61 FI piston. However I am curious as to whether it is GM. GM pistons generally didnt have the extreme indention in the center of the piston and the dome appears to contain more CCs than original. This is a observation and I might looking at them wrong. ie they might be GM.
Regards

cameo

Lunch is good anytime

anyone have a set of pistons I could use in a '57 fuely motor? kinda wanted originals if I could get them. My motor will have to go + .030"
is another catch.

1snake

I think you're right. My NOS pistons don't have any indentation. I can't tell if the dome is exactly the same height but, if not, it's very close.

Jim

OC-1

This was pulled form a 61, 315 in 1968.
cast # is 3768469.

raised portion is flat, photo may look like a bulge or convex.

JohnZ

Egge makes '57 F.I. domed pistons:

www.egge.com

john neas

Curious, do you have the serial # of the car that the piston came out of? It looks like your piston has a slight relief on the dome in the spark plug area. I remember a friend who was a previous owner of my 61 315HP #3860 put extended spark plugs in the heads and the dome closed the gap. By memory I believe I have seen a GM document which addressed the problem and possibly mentioned a fix and possibly a later piston design.
NOTE: I have been told that the 61 FI piston dome will not clear a 57 997 head without modifying the head.

verle

Ok, I went to John's shop and took pictures of some pistons.
57,61 and 65 (midyear HP) Fuel Injection
Notice the difference between the 57 and 61 dome shapes.
The 61 dome will not work with earlier heads because of combustion chamber difference, they will hit the head.
The 65 is similar to the 61 with a difference in the valve relief shapes and the 65 is a four inch bore.

57 FI still in the block
http://i35.tinypic.com/2ikcfma.jpg

61 FI
http://i36.tinypic.com/2crt1rk.jpg

65 FI
http://i37.tinypic.com/2py5m2q.jpg

john neas

Verle, thanks for posting the pictures. The 61FI pistons will clear the heads of the 57 283HPand 57 pass power pack heads. The #s etc on the 61 piston were put there by the people at JE when they built .070 over pistons for my 57 SCCA racer. I wanted to save the block that ran 57 Bridgehampton. The motor put a smile on Dick Guldstrands face when he ran it past redline last year at Meadowdale.
Regards

OC-1

John,

No serial # on my bros in law 's car. I believe it was April-ish as some of the parts I have show April dates. So it must be at least in the 7,000s.

He had a knock in #1 or #3 and when we took the piston out it was cracked on either side of the pin but all in one piece. Replaced and ran well until he bent a rod and broke the block about 3 years later.

Joe

john neas

Thanks

cameo

I'd like to thank you all for your imput. I am new to c1's and having fun learning all the details about them. Great pics, John and Joe and Verle

OC-1

Verle,

Is that 65 a service piston?

Thanks,
Joe

john neas

Joe, if you mean GM sevice piston, It is a NOS standard GM 4" bore piston. I assumed it was 327 maybe its a 350. Should have measured the pin height. Any comments are appreciated.
Regards

OC-1

Two pistons: one is a 327 replacement piston I purchased in the mid 70s. It matches exactly the pistons in a 1969 cast date CE 327 block.

The new piston is part# 3871208, cast# 3866954. Looks to be the same as the 65 photo Verle posted.

The other is in a March 64, 870 replacement block. Looks as if it was re-ringed with # stamped on the piston tops. Have not had any of those pistons out to look for the cast #. Assuming it is GM manufacture.
May be aftermarket of early 70s vintage?

Wondering about the differences between the two. Valve reliefs and presence of notchs???? Explained away if the pistons in the 870 block are aftermarket.

Optical illusion is really throwing my perspective off.