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06-23-2014, 09:28 AM | #181 |
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Re: Boring a flathead
thanks, i thought that it could be done on engine likes the engine is not tore down, do you have a measurement from a 239 stock piston that you could give me from the center of wrist pin the top edge of piston, by the way the the new 3 3/8 pistons are three ring pistons tell me and tell me if your measurement is to top edge or at the slight dome thanks so much, steve this would help so much
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v8fhtoys Last edited by steve tansy; 06-23-2014 at 02:18 PM. |
06-23-2014, 03:17 PM | #182 |
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Re: Boring a flathead
Just measured a stock 3 3/4 stroke piston (239) from the top of the wrist pin hole to the edge of the crown, not the top of the dome, but the start of it. I got 1.179".
For a 4" stroke you should have about 0.125" less. Hope that answers your question. Martin. |
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06-23-2014, 04:19 PM | #183 |
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Re: Boring a flathead
yes, that is what ron said to do i understand this i my problem right know i have not disassembled my engine i was hoping someone out there could please measure a 239 piston for me from middle of pin to top edge to the top edge of piston or crown thanks. steve
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06-23-2014, 04:40 PM | #184 |
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Re: Boring a flathead
You can use the measurement I gave you. You have the 3 3/8 pistons Sat there, measure them from the top of the wrist pin bore to the edge of the crown. If it's the same, they're 3 3/4 stroke, if they measure close to 0.125" less, they are 4" stroke.
Get it? Martin. |
06-23-2014, 05:10 PM | #185 |
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Re: Boring a flathead
Your reply has disappeared! Where did that go?
There must be ghosts. Martin. |
06-23-2014, 05:30 PM | #186 |
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Re: Boring a flathead
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06-23-2014, 06:09 PM | #187 |
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Re: Boring a flathead
THANKS, Martin, sorry for the mix up on my end your right .125 less than from .179 is .1054 4 inch stroke right on.Thanks again you have help me veary much .Steve
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06-23-2014, 07:26 PM | #188 |
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Re: Boring a flathead
CRS, Robert, what was the name of that guy that ran at Sanford back in the 50's, his name was on the back of 32 4dor? I believe he was in a wheelchair and built that engine. He had a young fellow drive the car. I remember standing behind that car when it took off down the 1/4 mile. It had wicked torque, I remember he usually turned 103-104 mph. I always wondered what he had it that engine. Walt
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06-24-2014, 01:30 AM | #189 |
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Re: Boring a flathead
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06-24-2014, 06:15 AM | #190 |
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Re: Boring a flathead
Hey, as long as we have some of the best minds on flatheads present answer one question for me. What purpose does having the center lines of the valves not the same on each bank? It must of been intentional, because the 85 and 60HP both have a three degree difference. Also the cam CL isn't lined up with the Crank CL. Thanks Chuck S.
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06-24-2014, 06:32 AM | #191 | |
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Re: Boring a flathead
Quote:
I am not pretending to be an expert and I'm curious about this as well. If I recall correctly, I thought I read that it has something to do with the crank or cam not being 100% centerline in the block. I can be way off, but has something to do with the way they cast the block that caused the need for the valve angles to be different from bank to bank. Experts, please enlighten us. Last edited by Tim Ayers; 06-24-2014 at 07:58 AM. |
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06-24-2014, 07:01 AM | #192 |
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Re: Boring a flathead
The definition of EX-Spurt is: An EX, is like an Ex wife or Ex president. A spurt is a drip under pressure. So an expert is just a drop.
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06-24-2014, 10:43 AM | #193 |
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Re: Boring a flathead
The cam being slightly shifted on the X axis required adjustments to be made so all the same valve parts could be used for each bank. Ford engineers decided on differing valve angles to be designed so all the components within the valve group can be the same part #--length--height--etc.
Maybe I am just a "drop". But a rather large one. |
06-24-2014, 01:35 PM | #194 |
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Re: Boring a flathead
Atta Boy John. I can just picture you with a coupla Beagles. Did the Alagator ever come back?
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06-24-2014, 02:00 PM | #195 |
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Re: Boring a flathead
As a side note, when Ford moved the valves farther away from the cylinders in 1946 to alleviate cracking between the valve seat and cylinder, they elected to go cheap and did not change the indexing on the cam.
The technical explanation for this is long and involved but the basic reason was tooling cost because they knew there were going to be major changes to the engine in 1949. The cams from 1946 to 1948 were ground on the same index as the 1942 and earlier ones. |
06-24-2014, 06:19 PM | #196 | |
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Re: Boring a flathead
Quote:
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06-24-2014, 06:35 PM | #197 |
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Re: Boring a flathead
Walt, sent you a PM. That was Carroll Sleeper's Fordor.
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06-24-2014, 07:29 PM | #198 |
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Re: Boring a flathead
I think the lifter bores went with the valves
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06-24-2014, 07:41 PM | #199 |
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Re: Boring a flathead
The valve timing to the engine will remain the same but the angle of the valves between the 2 banks changes. (bank separation) Therefore, the bank separation has to be changed on the cam.
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06-24-2014, 08:24 PM | #200 |
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Re: Boring a flathead
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