Never mind

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Some of this, and some of that should be considered. Until it's an actual creation, who knows. UNTIL IT'S AN ACTUAL CREATION. Step 1, follow through with seeing if the block will even do a .020 bore. I like the title "never mind".
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2021FLTRK said:
So I have searched everywhere, and am only seeing spotty information at best. Is anyone running KB399 pistons in a 318? What heads do you have and did you have any clearance issues? I have my block at the machine shop to get it cleaned up, bored and honed. They happen to have a set of KB399 pistons with rings and pins on the shelf from a project that never got used.

UEM Pistons

They will make me a deal on them, but I just want to make sure they will clear the heads adequately. I am running late 70s 360 heads with the 72cc chambers. It is a 1967 block that was just recently pulled out of the original car. The shop measured deck height at 9.59", and said one side is .002" taller than the other. He wanted to take that one down .002 so they match.

Been searching for data. Even spoke to UEM Pistons tech support. Everyone says the "think they should fit". I am paying to have this block bored, decked and the rotating assembly balanced, so I really want to be careful it goes together without having to change it. Any experience would be appreciated.
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This is not difficult. Use a vernier caliper to measure from the top of the pin bore to the top of the piston. Then add 1/2 the pin diameter, 1/2 the stroke and the con rod center to center length. That will tell you what you need for deck height. You can get away with +0.005" above the deck and adjust piston to head clearance with gasket thickness. With stock crank and rods and hyper esthetic pistons you can get down safely to 0.030" quench clearance. To keep the pistons from rocking, get Line2Line abradable skirt coating applied. On assembly, the pistons should go in almost snug. Then when you start it and there is no oil on the skirts, the abradable coating wears until oil gets in and it stops wearing. The coating is kind of porous, so it holds oil. This keeps skirt clearance to a minimum and the engine runs quieter due to no piston slap and holds the piston square in the bore.
 
2021FLTRK said:
With all due respect, I don't need to be told what to understand. I understand perfectly that I asked a specific question and people who had no answer to the actual question chose to offer unsolicited advice I already know. I am not saying they are not intelligent and experienced in the subject at hand. I am saying everyone chose to tell me a bunch of information I never asked for.

If I could delete this thread I would. It has been a massive waste of time.
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Check Summit web for KB399 pistons. Then scroll and click more specifications and scroll down to compression height. That shows 1.810".
1/2 stroke is 1.655""
Con rod is 6.123"
That totals 9.588"
The UEM site states the piston is 0.010" above a 9.578 deck height. So that matches. IMHO,I would let the machine shop skim the block for a deck height of 9.83". Then use a 0.035" compressed head gasket.
 
I know you don't get to pick and choose the responses, not unless your a mod :lol: .
But from the OP's 1st post below...I shortened it, but I haven't seen a single response in this thread that says YEP I've used these with xx heads. But in typical fabo fashion the thread goes sideways and at least 2 or 3 fights break out.
Meet ya at the bike rack!
2021FLTRK said:
So I have searched everywhere, and am only seeing spotty information at best. Is anyone running KB399 pistons in a 318? What heads do you have and did you have any clearance issues?

UEM Pistons

They will make me a deal on them, but I just want to make sure they will clear the heads adequately. I am running late 70s 360 heads with the 72cc chambers. It is a 1967 block that was just recently pulled out of the original car.

Been searching for data. Even spoke to UEM Pistons tech support. Everyone says the "think they should fit". I am paying to have this block bored, decked and the rotating assembly balanced, so I really want to be careful it goes together without having to change it. Any experience would be appreciated.
Click to expand...
 
4spdragtop said:
I know you don't get to pick and choose the responses, not unless your a mod :lol: .
But from the OP's 1st post below...I shortened it, but I haven't seen a single response in this thread that says YEP I've used these with xx heads. But in typical fabo fashion the thread goes sideways and at least 2 or 3 fights break out.
Meet ya at the bike rack!
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What is the point if someone else HAD used them? All block deck heights vary, all chamber sizes vary, all rod strokes vary in accuracy, so it would be a mute point. That's the point that I (as a engine builder who does this everyday) was trying to make. OP comes on early looking for some one to hold his hand and promise him it will just fall together like magic, so he can avoid paying his "machinist" to verify.
 
replicaracer43 said:
What is the point if someone else HAD used them? All block deck heights vary, all chamber sizes vary, all rod strokes vary in accuracy, so it would be a mute point. That's the point that I (as a engine builder who does this everyday) was trying to make. OP comes on early looking for some one to hold his hand and promise him it will just fall together like magic, so he can avoid paying his "machinist" to verify.
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After 50 years its all just like it rolled off the production line......
 
I realize and respect that you're an engine builder, and that all clearances are unique to each individual engine but I guess where we disagree is that he wants it to magically fall together and build itself. He was looking for experienced responses to those pistons in a 318. As I said I haven't read any response that said YEP.
replicaracer43 said:
What is the point if someone else HAD used them? All block deck heights vary, all chamber sizes vary, all rod strokes vary in accuracy, so it would be a mute point. That's the point that I (as a engine builder who does this everyday) was trying to make. OP comes on early looking for some one to hold his hand and promise him it will just fall together like magic, so he can avoid paying his "machinist" to verify.
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4spdragtop said:
I realize and respect that you're an engine builder, and that all clearances are unique to each individual engine but I guess where we disagree is that he wants it to magically fall together and build itself. He was looking for experienced responses to those pistons in a 318. As I said I haven't read any response that said YEP.
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They are DESIGNED to work in a 318, so YES they will work in a 318 with open chamber heads. BUT will require clearance checks for chambers, and to determine compression ratio. And most likely milling of domes, chambers and deck surface. I dont know why it's so hard for people to understand. Those pistons are NOT a drop in replacement, EVERY combo is different, so there is NOT a yes or no answer
 
replicaracer43 said:
They are DESIGNED to work in a 318, so YES they will work in a 318 with open chamber heads. BUT will require clearance checks for chambers, and to determine compression ratio. And most likely milling of domes, chambers and deck surface. I dont know why it's so hard for people to understand. Those pistons are NOT a drop in replacement, EVERY combo is different, so there is NOT a yes or no answer
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I don't think the answer can be more clear than this.
 
Everyone was trying to give the guy freindly advice, but he got all pissy about it, and doesn't appreciate people giving him HONEST input. He seems to want someone to just say "yes they just drop right in! Go for it!" I was trying to prepare him for what will be needed to make them work, but he acted like a dick instead.
 
I get it, it's not hard for me to understand lol. The OP simply asked questions, which is what this forum is for??
Not all engine questions are to try and **** the machinist outta money lol.
We'll just agree to disagree.
replicaracer43 said:
They are DESIGNED to work in a 318, so YES they will work in a 318 with open chamber heads. BUT will require clearance checks for chambers, and to determine compression ratio. And most likely milling of domes, chambers and deck surface. I dont know why it's so hard for people to understand. Those pistons are NOT a drop in replacement, EVERY combo is different, so there is NOT a yes or no answer
Click to expand...
 
2021FLTRK said:
So I have searched everywhere, and am only seeing spotty information at best. Is anyone running KB399 pistons in a 318? What heads do you have and did you have any clearance issues? I have my block at the machine shop to get it cleaned up, bored and honed. They happen to have a set of KB399 pistons with rings and pins on the shelf from a project that never got used.

UEM Pistons

They will make me a deal on them, but I just want to make sure they will clear the heads adequately. I am running late 70s 360 heads with the 72cc chambers. It is a 1967 block that was just recently pulled out of the original car. The shop measured deck height at 9.59", and said one side is .002" taller than the other. He wanted to take that one down .002 so they match.

Been searching for data. Even spoke to UEM Pistons tech support. Everyone says the "think they should fit". I am paying to have this block bored, decked and the rotating assembly balanced, so I really want to be careful it goes together without having to change it. Any experience would be appreciated.
Click to expand...
The Summit listing for the KB399 pistons states in the "check fit" that they fit the 5.2 Magnum engines. That would indicate there should be no problem with fitment. That said, the usual checking clearances with modeling clay strips must be undertaken. The 6cc dome crowns must be checked to clear the heads intended for the build. They should give fair compression ratio, like 10.5:1.
 
Dale Davies said:
The Summit listing for the KB399 pistons states in the "check fit" that they fit the 5.2 Magnum engines.
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I would never build an engine with any websites claims that anything will fit without checking myself first. Any piston with a positive deck height should be checked and never assumed to fit. Case in point the current small block I am assembling has been decked to zero a stock 318 piston. How much do you think they took of the decks?
 
Dale Davies said:
The Summit listing for the KB399 pistons states in the "check fit" that they fit the 5.2 Magnum engines. That would indicate there should be no problem with fitment. That said, the usual checking clearances with modeling clay strips must be undertaken. The 6cc dome crowns must be checked to clear the heads intended for the build. They should give fair compression ratio, like 10.5:1.
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The Quench Dome pistons sold by UEM come in a number of varieties, some are for different engines but within those engine sizes they also offer quench domes in different heights... Typically .070 and .140.... The .070 is generally an easy drop in piston when running typical open chamber heads that haven't been milled excessively... It can give effective but rarely ideal quench.... The .140 dome virtually always requires machine work to fit the chamber without crashing the dome into the head... But it can archive ideal quench.... As I stated previously, usually that requires machining the chambers of the heads because as cast it is common to see variations in the chamber depth... So you set the heads up on the mill & equalize the chamber depth... You need to mock up the engine to verify how far the domes are above the deck... Now you have a number for the piston dome height to be set to... So all the pistons get machined to the required dimension... And then comes balancing since the pistons obviously don't weight what they originally did...

But Hey, Summit said they fit so let's just throw them in & run it...
 
1WildRT said:
The Quench Dome pistons sold by UEM come in a number of varieties, some are for different engines but within those engine sizes they also offer quench domes in different heights... Typically .070 and .140.... The .070 is generally an easy drop in piston when running typical open chamber heads that haven't been milled excessively... It can give effective but rarely ideal quench.... The .140 dome virtually always requires machine work to fit the chamber without crashing the dome into the head... But it can archive ideal quench.... As I stated previously, usually that requires machining the chambers of the heads because as cast it is common to see variations in the chamber depth... So you set the heads up on the mill & equalize the chamber depth... You need to mock up the engine to verify how far the domes are above the deck... Now you have a number for the piston dome height to be set to... So all the pistons get machined to the required dimension... And then comes balancing since the pistons obviously don't weight what they originally did...

But Hey, Summit said they fit so let's just throw them in & run it...
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Some of you guys skim read or do not comprehend. I do not know how much 6cc domes protrude but definately not the biggest. Go back and read my post. I stated that clearances must be checked with clay to verify. If you do a factory stock rebuild it is fairly safe to toss parts at it with plastigage bearings. Once you build a custom engine, everything must be verified.
The OP asked if these pistons will work, and considering nobody came forward to say they have used them, I did a bit of research. Those pistons should work, with verification.
With the deck height the OP said the machinist reported to him, those pistons should be 0.002" down from the deck. Depending on the heads, the dome could possibly contact. Of course PT clearance must be verified with the selected cam.
 
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Dale Davies said:
Some of you guys skim read or do not comprehend. I do not know how much 6cc domes protrude but definately not the biggest. Go back and read my post. I stated that clearances must be checked with clay to verify. If you do a factory stock rebuild it is fairly safe to toss parts at it with plastigage bearings. Once you build a custom engine, everything must be verified.
The OP asked if these pistons will work, and considering nobody came forward to say they have used them, I did a bit of research. Those pistons should work, with verification.
With the deck height the OP said the machinist reported to him, those pistons should be 0.002" down from the deck. Depending on the heads, the dome could possibly contact. Of course PT clearance must be verified with the selected cam.
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The thing you are failing to grasp is compression height of the piston isn't the same as the total height from the center of the wrist pin... So while the piston surface used to calculate CH may be .010 in the hole that .140 dome is gonna protrude .130... And a typical Mopar open chamber measures around .100... So if bolted together without gaskets the piston will hit the head... Depending on the gasket chosen (a .070 Cometic for example) you could potentially get away with it... But it's not a path I would suggest... One chamber cast a little shallower & you'll have problems...

Not here to argue, really no concern of mine... O/P wasn't smart enough to listen to those who might know something so why bother...
 
1WildRT said:
The thing you are failing to grasp is compression height of the piston isn't the same as the total height from the center of the wrist pin... So while the piston surface used to calculate CH may be .010 in the hole that .140 dome is gonna protrude .130... And a typical Mopar open chamber measures around .100... So if bolted together without gaskets the piston will hit the head... Depending on the gasket chosen (a .070 Cometic for example) you could potentially get away with it... But it's not a path I would suggest... One chamber cast a little shallower & you'll have problems...

Not here to argue, really no concern of mine... O/P wasn't smart enough to listen to those who might know something so why bother...
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You seem to be the confused one. CH is from the center of the gudgeon pin to the top of the piston. The dome height is extra. If you read, I did say to clay the dome to determine any clearance issues and where. PV is another issue to deal with, that must be checked.
30 years as a mechanic and lifelong automotive enthusiast, I may know a bit.
 
good lord, who farted?

look, look, i'm not shaming anybody... but seriously who ever it was, you should probably go see a doctor. i think you're dying on the insides.
 
I don't get this entire thread. @2021FLTRK posts a thread titled "Never Mind", and all his post #1 says is "Never Mind"???
Then people start talking about 318 builds and pistons and a few people get really nasty and rude. What am I missing. If those people talked to me like that, they would get ignored so fast it would make their heads spin.
 
harrisonm said:
I don't get this entire thread. @2021FLTRK posts a thread titled "Never Mind", and all his post #1 says is "Never Mind"???
Then people start talking about 318 builds and pistons and a few people get really nasty and rude. What am I missing. If those people talked to me like that, they would get ignored so fast it would make their heads spin.
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OP asked if KB399 pistons will work for his build.
One person in particular tends to get snarky with people when his opinions and attitudes do not align with his. I do not abide that kind of BS and bullies.
Considering nobody stepped up that has used these pistons, I checked the manufacturer and Summit web sites, and both indicate they should work OK. I related that for the OP and got jumped on for that, at which I defend my actions or statements.
 
Dale Davies said:
OP asked if KB399 pistons will work for his build.
One person in particular tends to get snarky with people when his opinions and attitudes do not align with his. I do not abide that kind of BS and bullies.
Considering nobody stepped up that has used these pistons, I checked the manufacturer and Summit web sites, and both indicate they should work OK. I related that for the OP and got jumped on for that, at which I defend my actions or statements.
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akshually... you got jumped up on for getting chirpy for no reason other than sort of standing up for a guy who was being a jerkus because he didn't like the answers he was getting to his question; and and like, having this whole special topic about abiding BS and bullies, dude.

the answer was given almost immediately, or at least within 10 posts. then you came wading in late to the party (as usual) regurgitated some information and acted like you solved the mystery of who DB Cooper is, and got jumped up on again.
 
Lol. I read it differently but perception is just that....I believe the OP was looking for KNOWN issues(if any) with those, kinda like the China junk turn signal switches.
 
Dale Davies said:
OP asked if KB399 pistons will work for his build.
One person in particular tends to get snarky with people when his opinions and attitudes do not align with his. I do not abide that kind of BS and bullies.
Considering nobody stepped up that has used these pistons, I checked the manufacturer and Summit web sites, and both indicate they should work OK. I related that for the OP and got jumped on for that, at which I defend my actions or statements.
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I totally agree with your feelings on this. However, please look at post #1. All @2021FLTRK says is "Never Mind". It says nothing about pistons. That is why I don't understand what is going on.
 
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