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Originally Posted by BBYSTWY
(Post 4862478)
I like where this thread has gone! Keep it coming fellas....I'm not currently building engines trying to meet these goals just mainly opened it up for discussion...
Should we clear up some of the acronyms for us stupid people? CH CD etc? Is the general consensus that you can't get tq and hp up areound 700 with a GM 502 mag block then? In a 540 or 548 configuration? I read through everything and it seems like the hp is "easy" but tq will suffer...did I read that right? Thanks for all the replies! Turning into a very informative and fun thread I think! https://cimg0.ibsrv.net/gimg/www.off...a301cf5ed7.png |
Perfect thanks!
So from what was said here...less than the 1.270 you start getting into "not as reliable" territory? |
Originally Posted by BBYSTWY
(Post 4862482)
Perfect thanks!
So from what was said here...less than the 1.270 you start getting into "not as reliable" territory? That's what I'm reading. That said... If I were to start my fantasy engine, ideally, I'd have 4.53" bore pistons with 1.29-1.30" CH, which is not on their list of options. Did I read somewhere here on OSO that JE will make pistons to custom specs? Being a toolmaker of some skill, it doesn't seem to me that it would be any real feat to machine wrist pin holes .020" from a stock dimensions. BTW... I completely agree. I love the idea of doing Frankenstein builds. My model boating racing partner and I have cobbed together some pretty impressive engines in the past, boring out crankcases for larger cylinder sleeves, grafting non-OEM induction housings, shimming cylinder sleeves for longer rods and such. It's kinda fun when it all comes togther and actually works. I don't really see much of a difference here. Thanks. Brad. (937)545-8991 |
Originally Posted by Brad Christy
(Post 4862489)
BBYSTWY,
That's what I'm reading. That said... If I were to start my fantasy engine, ideally, I'd have 4.53" bore pistons with 1.29-1.30" CH, which is not on their list of options. Did I read somewhere here on OSO that JE will make pistons to custom specs? Being a toolmaker of some skill, it doesn't seem to me that it would be any real feat to machine wrist pin holes .020" from a stock dimensions. BTW... I completely agree. I love the idea of doing Frankenstein builds. My model boating racing partner and I have cobbed together some pretty impressive engines in the past, boring out crankcases for larger cylinder sleeves, grafting non-OEM induction housings, shimming cylinder sleeves for longer rods and such. It's kinda fun when it all comes togther and actually works. I don't really see much of a difference here. Thanks. Brad. (937)545-8991 And yes for the JE pistons....I was close to ordering custom pistons from them on my current engine...at the time it didn't really add any cost and back then(pre covid horsesh!t) they were only a couple weeks out so not bad at all I didn't think. |
Originally Posted by BBYSTWY
(Post 4862490)
Just a lot more money versus model boating hahahaha which is awesome btw! Assume you are actually talking about RC boat stuff right?
And yes for the JE pistons....I was close to ordering custom pistons from them on my current engine...at the time it didn't really add any cost and back then(pre covid horsesh!t) they were only a couple weeks out so not bad at all I didn't think. Yes. RC. Not nearly as inexpensive as you'd think, but, YES, way cheaper than our full-sized boats. Way more HP/ci from our model boat engines, though, being 2-stroke, 50-60% nitro and all. I see that now, exploring JE's website. This solves the math. Now, I just need to confirm... Stroke/rod/CH stackup should total short of the actual deck height, correct? Is that the "deck clearance" the diagram shows? Thanks. Brad. (937)545-8991 |
Originally Posted by articfriends
(Post 4862010)
Yes, Im building a 4.375/4.600 tall deck right now for a non boating application and its as simple as getting pistons with right Ch. If I was going to put a 4.25 stroke tall deck together, Id probably go 6.800 rod length to get some of the mass out of the piston, Smitty
So.... 10.200" tall deck 4.375" Stroke 6.700" Rods 4.53" bore, 1.310" CH Pistons Rod/stroke ratio of 1.53:1, and maximum rod angle of just over 18deg. Assuming JE's numbers relate directly to piston diameter, this would put the bore of the block at 4.535", making for 565ci. Perfect. Cam.....? Thanks. Brad. (937)545-8991 |
Custom pistons were 6 months out not that long ago.
If you hurt one, might be waiting a while. What about CR? N/A or blown? |
Originally Posted by ICDEDPPL
(Post 4862517)
Custom pistons were 6 months out not that long ago.
If you hurt one, might be waiting a while. What about CR? N/A or blown? We’re not actually building an engine. Just dreaming. And collecting info for the engine I WANNA build someday. The tread started as NA, and I know *I* can’t use a blower on a 565 in my current boat. The 565 is probably all the hull would really want. I can’t speak for anyone else, but I’m asking about NA. I have no idea about CR. I’m the student here. Thanks. Brad. (937)545-8991 |
Longer rods and good head make everyone happy. :party-smiley-004: Just sayin.
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Originally Posted by SB
(Post 4862522)
Longer rods and good head make everyone happy. :party-smiley-004: Just sayin.
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