Author Topic: Question regarding my compression ratio  (Read 1797 times)

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AmerigoHauler

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Question regarding my compression ratio
« on: August 18, 2017, 07:35:29 PM »
I have a couple of questions about the compression ratio of my FE. It is an “A” scratch 428 from a ’67 T-Bird. It was rebuilt sometime before I bought the truck it is in. The pistons are marked L2245 and are .030” over. (Photos below, I hope)

My 1st question is can anyone tell me who made these (TRW?) and also what the dish volume would actually be?

My other question is regarding the heads. I am running a set of out of the box Edelbrock #60065 heads. They claim 72 cc’s but I seem to recall reading somewhere that they run a little larger.

This engine has been back together and running fine for 14000 miles now. I plan on asking more questions about this engine but I wanted to be able to give a good answer regarding the compression ratio if it comes up. Using various online calculators and guessing on the piston dish I'm coming up with between a 9.6 and 10.2 ratio.

If someone wants to give me their calculation on this the other specs are:
Bore=4.16"
Stroke=3.98
Piston in the hole=.017"
Head gasket compressed=.038"
Head gasket bore=4.400" or volume=9.90cc's (Edelbrock 7337 head gasket)

Thanks, Erich

« Last Edit: August 18, 2017, 07:38:27 PM by AmerigoHauler »
Erich Weber
1974 F350 Super Camper Special
2004 Mercury Marauder

fomocoloco

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Re: Question regarding my compression ratio
« Reply #1 on: August 18, 2017, 08:27:53 PM »
according to my catalog 9.9-10.4. 68cc-74. they r indeed trw. my old catalog does not list  dish volume. i would say your are close in your calculations.


jim
« Last Edit: August 19, 2017, 08:01:16 AM by fomocoloco »
9 65-72  f100 sb trucks 6 428's 1 460 2 521 strokers
1 66 f100 lb ranger
3 67-75 f350
numerous parts vehicles and parts

AmerigoHauler

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Re: Question regarding my compression ratio
« Reply #2 on: August 19, 2017, 12:38:09 PM »
Thanks for that info Jim. I was surprised when I couldn't find any solid info on line. Helps me remember why I keep some of my old books and catalogs.

Thanks again, Erich
Erich Weber
1974 F350 Super Camper Special
2004 Mercury Marauder