Time to give it a rest AJ, you have had your day in the Sun . . .
Piston question
- Thread starter dartfreak75
- Start date
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Time to give it a rest AJ, you have had your day in the Sun . . .
Good luck with "THAT"! LOL
dartfreak75
Restore it, Dont part it!
I feel like I have started something I didnt mean to. I'm just wanting to learn and do the best I can with what i got. I'm not gonna start changing my build plan to get a particular number in compression. I have to buy new pistons so I'm just trying to get the best ones in my price range for my combo.
Like I said in my previous post I'm gonna go to the machine shop and measure my heads and see how deep the chamber is from the head surface If its doable to run quench then I will if its not I wont I'm not worried about it as long as I'm not in that .060 range if I'm .100 .130 out then I'm gonna run it and not worry about it. Sorry to cause so much rifes with this thread I'm just trying to learn.
Like I said in my previous post I'm gonna go to the machine shop and measure my heads and see how deep the chamber is from the head surface If its doable to run quench then I will if its not I wont I'm not worried about it as long as I'm not in that .060 range if I'm .100 .130 out then I'm gonna run it and not worry about it. Sorry to cause so much rifes with this thread I'm just trying to learn.
it's all good with me, buddy. I'm used to all their crap "do it this way or else" attitudes. Every build leaves power on the table. It's each individual's decision what they want to build. You and I have chatted enough that I know "just about" what you want. I like these type discussions. What I don't like is when some of these guys barge in telling members that what their doing won't run run worth crap unless they do "this this and this". You're not making any glaring mistakes. You're gonna have a great running engine and it's going to be really reliable. Keep on truckin brother!
OH MY !! It ain't rocket science.
Dartfreak stick to your plan and work with your machinist. He sounds like he's steering you right.
Dartfreak stick to your plan and work with your machinist. He sounds like he's steering you right.
dartfreak75
Restore it, Dont part it!
That's brother I just feel bad starting arguments between members haha I'm just trying to learn
pfffttt. Doesn't bother me. lol
I think for the most part, people really want to help, but some get offended when their suggestions are not followed.
No one really knows another person's wants, needs, budget or time constraints.
I probably won't update my build thread until it is running. I stated in the beginning that some of the parts weren't great, but they are what I have. Am I leaving power on the table? Yes, a truckload! But, I bet it will run better than the worn out 318 did before it died.
I got a couple "Do it once, do it right" comments, but I personally have no problem swapping cams with the motor in the vehicle. Same goes with intakes and carbs. I just want the dang thing running again.
So, build it and have fun! That is why we do this.
dartfreak75
Restore it, Dont part it!
With quench what is the max dynamic compression I can run and still use pump gas ?
Looks like I'm gonna be at about 9.3 dynamic with the kb107s
Looks like I'm gonna be at about 9.3 dynamic with the kb107s
dartfreak75
Restore it, Dont part it!
With that engine what is your dynamic compression? And are you running pump gas?
Wyrmrider
Well-Known Member
are using .050 for dca?
use .006
how did you come up with that 9.2 dca?
what's your real compression with the ft pistons and your miled heads and what gasket?
been there done that
50 years ago
some never or can't learn
you can
use .006
how did you come up with that 9.2 dca?
what's your real compression with the ft pistons and your miled heads and what gasket?
been there done that
50 years ago
some never or can't learn
you can
I don't mind one bit if somebody doesn't follow one of my suggestions. I realize my way of doing things is severely budget limited. That doesn't appeal to everyone and I get that.
What gets to me is when the same three or four people keep beating a dead horse of quench, Jones cams and "all of that" as if there's no other way. That's just not true. Although he's been in business a while at 1975, there are a lot of cam companies who've done it a lot longer. Their ideas are not garbage. I'll use Crower for a great example. Their camshafts are a fine example of great technology. Iskenderian is another. Schneider as well. There's always more than one way to get it done. I don't like it when people act like there's only one way, because that couldn't be further from the truth.
dartfreak75
Restore it, Dont part it!
I was using the wrong abdc! Haha I was using the timing event in the cam card I didnt do the formula to get lca abdc. I redid it and with the the kb107s at 10:1 I will be at 8.3 drc
Depends on the combustion chamber. There's a guy over on the Hamb who has an early Hemi. He's running 13:1 on pump gas. The Hemi chamber is very detonation resistant to begin with, plus he has everything else "just right". I cannot remember his screen name, but there's a member with a butterscotch Demon who runs up in the 11s on pump gas. Yes, small block and iron heads. It can be done, but it's alot of work to get there.
dartfreak75
Restore it, Dont part it!
I'm gonna just have to go to the shop on my next day off and measure the heads I'm kinda shooting in the dark Haha. I am gonna figure it all out before I order another set of pistons again tho lol
Have the shop cc the heads. That's all you need to do. ....unless you're suddenly going to try to go for quench <rolls eyes> then you need to measure the depth of the flat part of the chambers....plus, they all need to be VERY close to the same AND all of any sharp edges need to be polished away. Nothing for any hot spots to develop and cause detonation. As I said. It's a lot of work.
dartfreak75
Restore it, Dont part it!
What bugs me is when when I'm trying to solve one problem and you get that response just buy a new block or start over and do it this way. ( no offense to Aj) that bugs me. I have to buy new pistons regardless so if I can get in that quench range without spending 800 bucks on pistons and replacing the cam and rebalancing the cranks etc etc I'm game and I'm open to that I'm all about learning new things and thinking outside the box and if can get a set of hyper pistons in the 300 range to get me there or maybe a new headgasket I'm all for it. But I'm not gonna replace the block buy icon pistons and change my cam selection just so I can get quench. Its funny because I have seen it mentioned in many many threads and I have asked multiple times about it because I didnt understand it and ppl act like it's some top secret formula or something lol yr even said iv wrote pages and pages I'm not repeating myself again.
but after a quick Google search I found out it's pretty damn simple! It's just the distance from the chamber to the piston wtf is that so hard to explain ?
dartfreak75
Restore it, Dont part it!
I have not cc them yet since they have been cut. I did cc them before I had them cut and they cced between 70-72 thru the 8 of them
Cc'ing will give you the chamber volume. Measuring the depth of the chambers give you the quench distance information. You want that distance to be as close as possible from one chamber to the next. Then comes polishing all of the sharp edges and possible hot spots out. You can get pistons much less than 800 bucks with the KB Hyper......but your machinist doesn't like those. And I get that. But he needs to understand that's not the piston's fault. If he did the machine work and filed the rings (or didn't file them) it might be HIS fault. And THAT is something you should think about.
I normally never recommend quench in situations like this because 1) you're somewhat of a novice (no offense we all start somewhere) and 2) you're on a budget. Machining CORRECTLY for quench costs extra money.
Lastly, there's no amount of quench in the world that can save you from detonation in stop and go traffic when it's 95 degrees outside in high humidity if you're on the ragged edge. That's another reason why I don't recommend quench for a street car. You can end up not having a very streetable car if everything isn't perfect.
.....and when have you known anything to be "just perfect"?
Go along with these guys if you want to. It's your project, your money and your choice. But if you end up with something that you can barely drive, it won't be my fault.
And I didn't realize you didn't know what quench was. I never saw you ask....might have missed it so I assumed you knew.
Mopar open chamber heads are NOT quench heads to begin with. That's why making a Mopar engine a quench engine with stock type heads can be an expensive proposition. Since the flat part of the chamber is recessed, that's not productive for quench.
Look at ANY Chevy 350 head. Every DAMNED one of them was a quench head. Even the open chamber heads. The difference is the chamber on the Chevy heads is not the full circumference of the cylinder bore like the Mopar heads. There's no recess where the flat of the chamber is, opposite the spark plug like the Mopars, so it's VERY easy to get quench on the Chevy. Lots of them had quench from the factory, as most of their HP engines were two valve relief pistons with close to zero deck height and they all used the steel shim head gaskets early on.
So yes, quench distance is the space between the flat of the piston and the flat of the head opposite the spark plug. That's why I normally just ignore quench on a Mopar, because they are NOT quench engines at all to begin with using stock heads. Get it? It takes a LOT of work to get them there using stock type heads. That's why it's really best if you want a quench engine with a Mopar to get heads and pistons designed for quench.
But good God almighty. That's a lot of work and $$$$ for way less than 50 HP difference in the long run. It's just not worth it. Not on a build like yours. But as I said, it's your decision your money and your project.
Mopar open chamber heads are NOT quench heads to begin with. That's why making a Mopar engine a quench engine with stock type heads can be an expensive proposition. Since the flat part of the chamber is recessed, that's not productive for quench.
Look at ANY Chevy 350 head. Every DAMNED one of them was a quench head. Even the open chamber heads. The difference is the chamber on the Chevy heads is not the full circumference of the cylinder bore like the Mopar heads. There's no recess where the flat of the chamber is, opposite the spark plug like the Mopars, so it's VERY easy to get quench on the Chevy. Lots of them had quench from the factory, as most of their HP engines were two valve relief pistons with close to zero deck height and they all used the steel shim head gaskets early on.
So yes, quench distance is the space between the flat of the piston and the flat of the head opposite the spark plug. That's why I normally just ignore quench on a Mopar, because they are NOT quench engines at all to begin with using stock heads. Get it? It takes a LOT of work to get them there using stock type heads. That's why it's really best if you want a quench engine with a Mopar to get heads and pistons designed for quench.
But good God almighty. That's a lot of work and $$$$ for way less than 50 HP difference in the long run. It's just not worth it. Not on a build like yours. But as I said, it's your decision your money and your project.
My Low Budget has become No Budget, so I know what you mean. I am fortunate that I have some good parts already, but will have to sell some parts, or trade some to get other parts I need, but that is all part of the fun, at least for me.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I think I'm detecting some flack directed at me, it's really hard to tell when "people" don't come right out and say it. I'm not smart that way.
But if that's true, then in response to it, I can only say that I'm on the Op's side no matter how my thoughts/comments are interpreted. I offered suggestions that can take a ho-hum combo, to be a dynomite streeter, irrespective of absolute power. As we all know, at least I think we all know, that for a streeter, absolute power is not the primary goal. Altho, more or less "free" power, in my books is never a bad thing.
Everything I offered was in discussion form, attended by examples. Nowhere did I say to do such and such, or else.
Look, in 1998 when I built my engine, there was NO machine shop willing to build my engine my way, even tho they all made good coin building successful race engines. So I had one shop do this and another do that,etc, until I had what I wanted, and then assembled it myself. Which turned out to be "a" pattern, if not "the" pattern, for many guys after me, including some guys right here on FABO, and even one big-name business built and hyped his version..
I came into this, at a time in history, when this type of street engine was in it's infancy, and my homework just happened to work.And I think the results speak for themselves. Now everybody builds; tight-Q ,alloy headed, powerhouses.
But I get that not everybody goes down the same path; some go the old way, and some the new way. I just thought, that since the engine was blown apart anyway, well you know what I thought.
To the Op;
We're pretty much all friends here, and I for one, do not hold grudges, and try not to venture into uncharted for me territory. Sometimes I do get over-zealous, like in the N&P forum, and sometimes it spills over into other forums. But, I'm always willing to make and keep the peace.
If it is the case, that Rusty is pointing to me, I will gladly bow to his expertise, and without any hard feelings.
But in the future, I will continue to sing praises for tight-Q.
But if that's true, then in response to it, I can only say that I'm on the Op's side no matter how my thoughts/comments are interpreted. I offered suggestions that can take a ho-hum combo, to be a dynomite streeter, irrespective of absolute power. As we all know, at least I think we all know, that for a streeter, absolute power is not the primary goal. Altho, more or less "free" power, in my books is never a bad thing.
Everything I offered was in discussion form, attended by examples. Nowhere did I say to do such and such, or else.
Look, in 1998 when I built my engine, there was NO machine shop willing to build my engine my way, even tho they all made good coin building successful race engines. So I had one shop do this and another do that,etc, until I had what I wanted, and then assembled it myself. Which turned out to be "a" pattern, if not "the" pattern, for many guys after me, including some guys right here on FABO, and even one big-name business built and hyped his version..
I came into this, at a time in history, when this type of street engine was in it's infancy, and my homework just happened to work.And I think the results speak for themselves. Now everybody builds; tight-Q ,alloy headed, powerhouses.
But I get that not everybody goes down the same path; some go the old way, and some the new way. I just thought, that since the engine was blown apart anyway, well you know what I thought.
To the Op;
We're pretty much all friends here, and I for one, do not hold grudges, and try not to venture into uncharted for me territory. Sometimes I do get over-zealous, like in the N&P forum, and sometimes it spills over into other forums. But, I'm always willing to make and keep the peace.
If it is the case, that Rusty is pointing to me, I will gladly bow to his expertise, and without any hard feelings.
But in the future, I will continue to sing praises for tight-Q.
Well you know me well enough I hope that if I wanted to direct flack at you or anybody else, there'd be no question whatsoever about it.
Don't feel like the Lone Ranger, because it wasn't "just" you I was directing it towards. All you guys talkin all these numbers and quench and Jones cams come on here crammin it all down everybody's throats and it gets tiresome after a while. There are lots of great cam companies and plenty of engines run just fine with .100" and more of "quench" distance. Even the stock early 340 didn't have quench for crap. The piston was out of the hole what? .025"? Plus the .020" steel head gasket plus the "about" .095" chamber depth. Yeah, it "might" have been better than a negative deck height, but there was little to no quench going on and they all still ran like hell. Much the same with any of the Super Commando 440s.....and MILLIONS of private builds from then till now.
All my point is, yall all act like you caint do it any other way.....and yall are all WRONG as HELL about that. That's the flack I'm slingin. Get used to it, because I'm not apologizing for being right.
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And I cannot agree more. We ARE all friends here as far as I'm concerned. Much like family. We can have disagreements. I have immense respect for you and all your numbers even though I like to troll you every now and then. I know you have vast knowledge...but you need to realize sometimes that there are more ways than one to do things and do them successfully.
Wyrmrider
Well-Known Member
In OP's case he has to buy pistons
He could get cast rebuilder pistons for less and if he is going to get FT pistons he might as well
He can get 0 deck FT pistons for just a little more but he needs to keep his compression resonable for no quench
or he can get the quenh dome KBs for about the same and build a higher compression ping resistant engine
with some more work but not that much more compared to the whole build
thanks for the explanation RR - you nailed it- stupid 68 smog head Mopar decision
and it's not about the 20-50 hp
you can get more race fuel race compression HP with an open chamber head
just don't drivei it below peak torque
we did that in stock classes like forever
op what cam are you referring to?
Mopar's are not inexpensive to build
yes closed chamber heads are a better option but heads + Pistons are out of many's budgetss
When we were rebuilding Chrysler Motorhome and bus motors we were had to change the pistons too but there were no aftermarket heads available- first we welded up the hambers and used a piston designed lie the Famour TRW "Turbo" piston- a D cup
then quench dome piston from my late good buddy Nick Arrias we used to have lunch together with ED and big John in Gardena every Wednesday
Those forged pistons were not cheap but cheaper than welding the chambers and pistons
essentialy the same choices today and for the same reasons- or not
first we
He could get cast rebuilder pistons for less and if he is going to get FT pistons he might as well
He can get 0 deck FT pistons for just a little more but he needs to keep his compression resonable for no quench
or he can get the quenh dome KBs for about the same and build a higher compression ping resistant engine
with some more work but not that much more compared to the whole build
thanks for the explanation RR - you nailed it- stupid 68 smog head Mopar decision
and it's not about the 20-50 hp
you can get more race fuel race compression HP with an open chamber head
just don't drivei it below peak torque
we did that in stock classes like forever
op what cam are you referring to?
Mopar's are not inexpensive to build
yes closed chamber heads are a better option but heads + Pistons are out of many's budgetss
When we were rebuilding Chrysler Motorhome and bus motors we were had to change the pistons too but there were no aftermarket heads available- first we welded up the hambers and used a piston designed lie the Famour TRW "Turbo" piston- a D cup
then quench dome piston from my late good buddy Nick Arrias we used to have lunch together with ED and big John in Gardena every Wednesday
Those forged pistons were not cheap but cheaper than welding the chambers and pistons
essentialy the same choices today and for the same reasons- or not
first we
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