318 pistons

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eeka440

eeka440

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I just tore my 69 318 down and found what appears to be factory pistons without valve reliefs. I haven't seen this before. The engine has never been apart before as far as I can tell.
Are these factory pistons or aftermarket?
 
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Never heard of OEM 318 pistons with valve reliefs. 340-yes, 273-maybe the high compression versions, 360-also never.
 
Probably cause 318 pistons are so far down in the hole and the camshaft are so small no chance of them seeing each other
 
The factory used so many different pistons for the 318 you never know what you'll find.
 
Rusty is right, I did a lot of research on 1968/69 318 engines. I checked several stock engines by my self and can confirm that you can find both pistons in them. Even the book on how to rebuild a small block is wrong on this subject. They put in there whatever was available. More important is to check the standard size of the pistons and bearings.
Here pictures of stock factory 68 318:

IMG_20191115_152408_01.jpg


IMG_20191115_152411_01.jpg


IMG_20191202_130530953.jpg
 
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Here a capture from the famous and well written Larry Hofer small block book - but the information is not correct - pistons were mixed.

IMG_20201227_221320917~2.jpg
 
I never seen them without the 4 brows....pics? A flat top is a flat top, brows or not. 360 always had the dish and the 273/4 had the wedge top as well as the 2 340 styles....2 brow high comp and later 4 brow low comp.
 
They also used a wide variety of compression heights as well.
 
I remember seeing flat tops in 67-69's I believe.
 
First one to post a pic of a no brow stock 318 LA piston from any year gets $0.79 via paypal from me...that's all I got left. Would be pretty hard to tell if its stock unless its got a Chrysler number on the bottom. I'm afraid Ill be keeping my money. All I've seen are 4 brow flat tops.
 
pishta said:
First one to post a pic of a no brow stock 318 LA piston from any year gets $0.79 via paypal from me...that's all I got left. Would be pretty hard to tell if its stock unless its got a Chrysler number on the bottom. I'm afraid Ill be keeping my money. All I've seen are 4 brow flat tops.
Click to expand...
I'm looking for a photo. I'll look in the service. Manual tomorrow but all I have is a 70 manual and I am sure they are double eyebrows. The OP needs to find out if his are oversized. Probably TRW's or Silvolites.
 
Check the rod bearings for a 68 date code. Very few would put in a smooth aftermarket piston and not change the rod bearings while they were down there.
 
pishta said:
First one to post a pic of a no brow stock 318 LA piston from any year gets $0.79 via paypal from me...that's all I got left. Would be pretty hard to tell if its stock unless its got a Chrysler number on the bottom. I'm afraid Ill be keeping my money. All I've seen are 4 brow flat tops.
Click to expand...

Here's a 318 flat top with no reliefs and the part number
rqgz4Ylh.jpg

uhruabc-jpg.jpg
 
pishta said:
First one to post a pic of a no brow stock 318 LA piston from any year gets $0.79 via paypal from me...that's all I got left. Would be pretty hard to tell if its stock unless its got a Chrysler number on the bottom. I'm afraid Ill be keeping my money. All I've seen are 4 brow flat tops.
Click to expand...
1984 318 stock pistons.

Kuva2714.jpg
 
Aw snap! Do we have a winner? post up that part number, cant read it. With that low of a deck height I wonder if its a 318 truck piston?

@Mr Dart Part numbers?

Someone may be .79 cents richer!
 
pishta said:
Aw snap! Do we have a winner? post up that part number, cant read it. With that low of a deck height I wonder if its a 318 truck piston?


Someone may be .79 cents richer!
Click to expand...
Haha. Don't want your 79 cents. Haha. And what is .79 cents? 79/100th of a penny? Not sure if it's a truck engine. Has a forged crank, bushed rods. All scores for me.

RZWyX9Eh.jpg

LWlD7sxh.jpg
 
It's real easy to see how many different pistons came in 318s. Look at how many different pistons Silv O Lite offers for the 318. That's ALL they offer is stock factory replacement pistons. There are two compression heights and two piston head styles.
 
pishta said:
Aw snap! Do we have a winner? post up that part number, cant read it. With that low of a deck height I wonder if its a 318 truck piston?

@Mr Dart Part numbers?

Someone may be .79 cents richer!
Click to expand...
I am sorry I don´t have those pistons anymore. Picture is over a year old. Those were pressed pins and old pistons were left to machine shop who pressed new pistons in. So you can stick to your money. :lol:
 
Here are some pictures. There is a Chrysler part number and Pentastar on the underside, so I guess I answered my own question. The bearings are marked 1969 and it's a 69 engine. A jumped timing chain seems to have left its mark on the top of the pistons. The compression height is 1.777 as measured.
Thanks for your inputs.

IMG_20201228_155119.jpg


IMG_20201228_155151.jpg
 
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Interesting.....well you caught my .79 cent joke! No, I actually have $0.79 in paypal and your welcome to it. Thanks for the pics, I learned something today.
moparsmallblockpiston-rodschart-jpg.jpg
 
My '68 block had the four eyebrow pistons and my '86 had none. I never took the time to measure the compression height on the '68 pistons since they got replaced with dome pistons, but I may still have them laying around somewhere.
 
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