What do you think of this build
- Thread starter straightlinespeed
- Start date
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straightlinespeed
Sometimes I pretend to be normal
Im curious, where or how did you come up with the .040 quench area?
I have not gotten the heads or the engine disassembled yet. Im trying to get everything lined up before I tear it down.
I have not gotten the heads or the engine disassembled yet. Im trying to get everything lined up before I tear it down.
nm9stheham
Well-Known Member
.040" (.035" minimum) is a recommended quench gap; much more and the velocity of the 'squirt' drops; much less and the risk is of piston/head collision.
Here are some more app notes that cover the 2 KB pistons being discussed. I'd like to find this kind of info squirreled away on the KB site......probably have to just call KB and ask for it.
http://www.campbellenterprises.com/mopar_kb_pistons.htm
(The narrowing of the piston rod applies to the magnum engine, I do believe it says on the KB site...)
Here are some more app notes that cover the 2 KB pistons being discussed. I'd like to find this kind of info squirreled away on the KB site......probably have to just call KB and ask for it.
http://www.campbellenterprises.com/mopar_kb_pistons.htm
(The narrowing of the piston rod applies to the magnum engine, I do believe it says on the KB site...)
straightlinespeed
Sometimes I pretend to be normal
10-4 on the quench #'s
It sounds like a lot more work is needed to get those 232's to fit, such as possibly milling the heads. Just for roughly a .1 point change.
It sounds like a lot more work is needed to get those 232's to fit, such as possibly milling the heads. Just for roughly a .1 point change.
nm9stheham
Well-Known Member
And to add to the the confusion....looking at the pix of these 2 pistons from KB on the Mancini site.....the pix are different, and the 323's don't have finished valve pockets. Looks to be mandatory to call KB to get the right info! If I get time tomorrow, I'll call myself (no, I won't call TO myself...LOL), I need to know too.
The milling may or may not be an issue. Our local shop has a piston jig ready to go and can do a simple flat mill of a few 10's of thousandths on a set of 8 piston tops in an hour or so. Not a big deal for us.
Thanks for bring up the topic BTW; I needed to go through all of this too.
The milling may or may not be an issue. Our local shop has a piston jig ready to go and can do a simple flat mill of a few 10's of thousandths on a set of 8 piston tops in an hour or so. Not a big deal for us.
Thanks for bring up the topic BTW; I needed to go through all of this too.
straightlinespeed
Sometimes I pretend to be normal
No problem!
I wish they (any company) made a piston in the middle of the 232/362 and the 107's. Something with around 10cc or so so you can get from 9.8 to 9.5 SCR depending on your heads.
It just stumps me and there is probably a reason they dont, but for those of us that want that range its not cut and dry. Or again it is and Im just dumb.
I wish they (any company) made a piston in the middle of the 232/362 and the 107's. Something with around 10cc or so so you can get from 9.8 to 9.5 SCR depending on your heads.
It just stumps me and there is probably a reason they dont, but for those of us that want that range its not cut and dry. Or again it is and Im just dumb.
Then don't use the KB pistons. There ARE other alternatives.
What are those K.B's gonna run you,on an estimate? 350-400 bills? A couple hundo more,some selective custom forged might be had,6 bills,or so... Do some hunting, a custom CNC piston,isn't too much more.. J M.O.
While I know this isn't cut and dry, the Speed Pro's give you an idea on the site as to CR based on what cc your heads are.
For example: H116CP 30 will put you at 65cc head=9.85, 71cc head=9.26.
I know it's just a reference, and you really need to calculate the CR, but it does give an idea.
You can get the Mahle forged pistons for about that price
straightlinespeed
Sometimes I pretend to be normal
So far from what I've seen there is nothing in between. Im not stuck on the KB's, but my search has found most or all pistons are the same.
Never thought about having some custom ones made. Thanks
I know that the advertised CC for the head can vary a lot. Such as my magnum heads are advertised at 62cc, talking with Mike at MRL he has never seen any set of heads come in at advertised. Usually way more! So I could have a 65, 67 or ???? head. I have to check that. But just going off of advertise for the time being. I would be pushing 10 SCR, isnt that to much for iron heads?
I'll look into this brand, thanks
Summit has a buret and plate for about 30 bucks, get it and cc yer heads then you'll know. Although their site is down at the moment, I just tried to order one. :banghead:
Here's what I'm talkin about: http://www.ebay.com/itm/summit-racing-cylinder-head-cc-kit-980180-/331374933924
I would think knowing that will help in the decision process. And yes, 10 is pushing it, I'm trying real hard to come in at 9.5 and I think I'm close with the pistons and heads I have.
I am going to get that kit and then I will know exactly where I stand. Then it's just a matter of choosing the correct head gasket thickness.
autoxcuda
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I agree.
Find out exactly the CC's of the heads you have before you go out buying pistons. They sound used so you don't know where you are at.
Sounds like someone probably choose the wrong parts last time, don't do it again.
I've got the XE 274 cam with 9.8 compression (measured and calc'd) with aluminum heads. I run 91 Octane and it with barely ping on a very hot day under heavy load up a steep grade with full throttle.
straightlinespeed
Sometimes I pretend to be normal
Here ya go, save some money, buy this and a piece of plexi glass and your set. 1cc= 1ml.
http://www.ebay.com/itm/141634873403?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
autoxcuda
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If you just grease the plexiglass plate you don't need to bolt it down.
mderoy340
Well-Known Member
I cc'd my magnum heads a few days ago and they were 62
Have fun drilling the hole in it, drill, crack, back to the store. Drill, crack, back to the store.
Rinse and repeat, lmao.
It can be done, but I usually screw up a piece or two first.
straightlinespeed
Sometimes I pretend to be normal
That is good to know, I'll post results of mine when I do it but it will be some time.
Slow, I repeat slow.... Better yet buy a small piece of Lexan, it doesnt shatter or crack. Start small and keep stepping up until you get to the size you want..
Just trying to save ya some money.
Yeah, I just run the two sharp edges off a bit so it don't catch. 
nm9stheham
Well-Known Member
Just be aware that if the glass is not tight to the head you can add considerable volume to the measurement. If the plate is .010" off the head surface of an open chamber SBM head with some goop sealing it, you've just added 2 whole cc's to the measurement.
Then you aint lookin. The Speed Pros all have a "little" lower compression.
straightlinespeed
Sometimes I pretend to be normal
I did see that. It took me a few hours today, to figure out how they where coming up with lower compression with the same head volume as other brands. Its all in the compression height!
straightlinespeed
Sometimes I pretend to be normal
Nope its how I learn... Being told is one thing, figuring out why is another.. I will get this, you will all have to suffer thru it with me, and put up with my dumb questions! hahahaha Sucka!!!
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