I dont think it sounds like your picking a fight at all, just sayin.
I wonder if all the goop ( there was a ton of it on the intake manifold ) was because the head gasket was too tall ( just throwin it out there )
I do want to learn something
340 build
- Thread starter 1930
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I wonder if all the goop ( there was a ton of it on the intake manifold ) was because the head gasket was too tall ( just throwin it out there )
I do want to learn something
Quote: 1930 please tell me you mark the piston or the rod before you pulled them out..........
What you mean, I pulled the piston connecting rod assy from each cylinder on at a time, I placed them on my bench in the same order they were removed front to back side to side.
Do I need to keep them in this same order? I thought that it wouldnt matter what order they went back in only that they were facing the correct direction and that direction was somehow indicated on the assy?
What you mean, I pulled the piston connecting rod assy from each cylinder on at a time, I placed them on my bench in the same order they were removed front to back side to side.
Do I need to keep them in this same order? I thought that it wouldnt matter what order they went back in only that they were facing the correct direction and that direction was somehow indicated on the assy?
They miced the bores, my measurements were close enough, they told me they averaged ..004 thousand over the 4.10. They suggest cleaning/honing the bores as best as possible, some of the rust spots will prob. remain, possibly some of the scratched down low in the cylinder where the piston skirt rubbed may remain and putting file fit 65 rings in it.
I guess Im still not understanding something, they make it sound like its got .004 wear, my take on whats been posted so far had me thinking that because forged pistons were being used ( the last time it was rebuilt ) and these forged pistons required approx ( off the top of my head ) .004 clearance to allow for expansion that the cylinders would have been bored 4.104.
I guess im wrong, they would or should have measured the forged pistons and final fit the cylinder to be just at the dimension of the piston plus .004 thou.
Am I on track now?
I know zero about any of this but would like to understand.
I guess Im still not understanding something, they make it sound like its got .004 wear, my take on whats been posted so far had me thinking that because forged pistons were being used ( the last time it was rebuilt ) and these forged pistons required approx ( off the top of my head ) .004 clearance to allow for expansion that the cylinders would have been bored 4.104.
I guess im wrong, they would or should have measured the forged pistons and final fit the cylinder to be just at the dimension of the piston plus .004 thou.
Am I on track now?
I know zero about any of this but would like to understand.
Mopar have marking on the big end of the rod...they should be numbered 1 thru 8......keep the rod and cop caps together...which should be easy since they are numbered
No picture but if you look at your picture, you can see where the valve smashed down on the piston, but there was no mark in the actual valve pocket. that shelf keeps the deeper valve pocket form being used. they are hitting the 90 degree shelf first.
If you grind of that shelf so it is the same angle as the valve pocket, you just gained, (as i keep saying
) a boatload more clearance. we are talking about thousands of an inch here and that 90 degree shelf has.......I don't know .020 to get it to the stock valve relief????
Latter i will look up my old valve to piston clearance and share them with you, to show the difference it made.
Have to find my notes first.
Earlier i said to us a cut of wheel to do the job. Have changed my mind. us a die grinder and a alu bit or a sand paper roll on a die grinder. make sure you clean up any sharp edges. you could even replace the die grinder for a drill for that matter.
If you grind of that shelf so it is the same angle as the valve pocket, you just gained, (as i keep saying
) a boatload more clearance. we are talking about thousands of an inch here and that 90 degree shelf has.......I don't know .020 to get it to the stock valve relief???? Latter i will look up my old valve to piston clearance and share them with you, to show the difference it made.
Have to find my notes first.
Earlier i said to us a cut of wheel to do the job. Have changed my mind. us a die grinder and a alu bit or a sand paper roll on a die grinder. make sure you clean up any sharp edges. you could even replace the die grinder for a drill for that matter.
joec
Well-Known Member
While it is good practice to keep the pushrods/rockers in order if not no big deal.Have the machine shop check the balance while its there.The valve pockets can be laid back without machining the tops,hell its only the intake pockets you can probably do that with a dremel.You already have witness marks.While checking the valves for straightness before you pull the heads apart fill the champers with alcahol or dry gas to see if they leak if not and free in the guide get some lapping compound and check the seats as 318 will run showed in his 318 build.You have to buy a cam and lifters anyway so have the machine shop check valve spring for enough pressure for the cam.If the bores arent bad you could probably give it a quick hone and your ok.
joec
Well-Known Member
Also usually if you try to externally balance an internal crank they have to add heavy metal not lighten it.Most of the time its a pain and does not turn out too good.
You might want to rethink that..LOL....If you adding weight externally....you have remove weight internally not add weight ....
Now went internally balance an externally balanced crank..you are adding weight to the crank from the external balancer and converter to the crank...
Too many cooks in the kitchen....receipt for a big FU....LOL
nm9stheham
Well-Known Member
I was really hoping that would be the case, and if a few scratches and pits remain, that is OK. I would normally want to get them all out with a fresh bore, but 340 blocks are reputed to be more problematic as to how far you can bore them, as their bores start pretty big to begin with. And over .060" would be .080" and new pistons and that cost, and the bores might just not take it. I would want to run it as is and get what life I could out of it. If you want to run it on the street for a while, then ask them to hone it the least they think they can get away with for a good ring seal, and let it go at that.
(Just do your best to get any loose rust particles out of any pits; iron oxide is an abrasive.)
The point on the piston order is that it does not matter. These pistons do not have what is called 'pin offset' and so don't have the notch on them that indicates what side of the piston points to the front. If they had notches then you would have to keep them on the correct side. You can mix and match these as you see fit. For lack of any other reason, I'd put the shortest rod and pistons sets up front, where the deck looks to be the shortest. Just make sure that the oil squirt hole is aligned in the right direction on each rod with the piston eyebrows 'up'.
And spend some time after it comes from the shop to clean, clean, clean, the block and crank. There could well be some grit and cam bits left despite their cleaning efforts.
Just to clarify, and to help the OP understand.
When he says Heavy Metal, think in terms of Gold!!!!!! NO that's not the heavy metal, but that stuff is Expensive!!!!!!!!!
I would not have noticed that unless you mentioned it, some of them are very faint, the number 7 is almost nonexistant and is only marked on the rod portion and not the cap
No picture but if you look at your picture, you can see where the valve smashed down on the piston, but there was no mark in the actual valve pocket. that shelf keeps the deeper valve pocket form being used. they are hitting the 90 degree shelf first.
If you grind of that shelf so it is the same angle as the valve pocket, you just gained, (as i keep saying
Latter i will look up my old valve to piston clearance and share them with you, to show the difference it made.
Have to find my notes first.
Earlier i said to us a cut of wheel to do the job. Have changed my mind. us a die grinder and a alu bit or a sand paper roll on a die grinder. make sure you clean up any sharp edges. you could even replace the die grinder for a drill for that matter.
Got it, thanks
I did fill with alchohal with no leaks, I cant properly check the valves for straightness Im told so I told the machine shop to check them for me, they are going to lightly resurface the heads and do a valve job.
They need to know roughly what cam Im gonna use so they can check the springs properly, I told them Id get back with them
I forgot to ask the machine shop to square the deck. Im assuming that would be a good thing to have done?
Ok got it
Squaring the deck is always a good idea... but, think about this. Your tallest piston is .020 out of the hole, and your lowest was .....012? right? So that means that you will have all of your pistons popping up .020 now right? (that's not 100% correct because you may have some rods that were recondition that cause the rod to be 1 or 2 Thou shorter than the rest)
In reality, you will have piston the set above the deck from .019-.022 above the deck. you could have the rod "blue printed" (reconditioned to have all the rods the same length) but that is a preciseness that cost money.(Maybe you will have to ask the machine shop)
If i was going down that rod i would just buy a good Q aftermarket rod. they are much lighter AND stronger and would have to be decided before any balancing is done.
When i get back, i just might send your thread off track a little. but you want to learn and this may be a learned subject for us both.
In reality, you will have piston the set above the deck from .019-.022 above the deck. you could have the rod "blue printed" (reconditioned to have all the rods the same length) but that is a preciseness that cost money.(Maybe you will have to ask the machine shop)
If i was going down that rod i would just buy a good Q aftermarket rod. they are much lighter AND stronger and would have to be decided before any balancing is done.
When i get back, i just might send your thread off track a little. but you want to learn and this may be a learned subject for us both.
Well a little disappointed in myself but these were all most 20 year ago now.
found my notes, I didn't right the specs for valve to piston clearance down. notes only said that i use a .020 steel shim head gasket and that i had to grind off the shelf of the pistons valve relief to get proper valve to piston clearance.
From memory(o Boy) i do remember that one of the valve hit the valve guide before it hit the piston top.
When you get ready to check valve to piston clearance you will have a light checking spring installed onto one cyl intake and exh valve. you will rotate eng over a little at a time stopping to push intake and exh valves all the way to the guide(bottoming out) when you hit the piston, you install a dial indicator on the valve stem and keep nudging you eng over and check clearance. when it start to grow instead of get small. that's you Valve to piston clearance.
note this is with your cam pushrod and rocker arms installed.
but these were all most 20 year ago now.found my notes, I didn't right the specs for valve to piston clearance down. notes only said that i use a .020 steel shim head gasket and that i had to grind off the shelf of the pistons valve relief to get proper valve to piston clearance.
From memory(o Boy) i do remember that one of the valve hit the valve guide before it hit the piston top.
When you get ready to check valve to piston clearance you will have a light checking spring installed onto one cyl intake and exh valve. you will rotate eng over a little at a time stopping to push intake and exh valves all the way to the guide(bottoming out) when you hit the piston, you install a dial indicator on the valve stem and keep nudging you eng over and check clearance. when it start to grow instead of get small. that's you Valve to piston clearance.
note this is with your cam pushrod and rocker arms installed.
joec
Well-Known Member
Well better rethink that Chef.When i had it done it needed heavy metal.Plus the speedpro pistons need looser piston to wall .004 would be my minimum .Their forged expand more.Im not trying to tell the op what to do, just agreeing with other posters.Also I dont think it needs .065 file fit rings. BY BY.
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Thats ok it prob. would have confused me anyway, where do I get one of these light checking springs, Ive read about this. Youll prob. have to remind and repeat in that order by the time I get there.Well a little disappointed in myself
found my notes, I didn't right the specs for valve to piston clearance down. notes only said that i use a .020 steel shim head gasket and that i had to grind off the shelf of the pistons valve relief to get proper valve to piston clearance.
From memory(o Boy) i do remember that one of the valve hit the valve guide before it hit the piston top.
When you get ready to check valve to piston clearance you will have a light checking spring installed onto one cyl intake and exh valve. you will rotate eng over a little at a time stopping to push intake and exh valves all the way to the guide(bottoming out) when you hit the piston, you install a dial indicator on the valve stem and keep nudging you eng over and check clearance. when it start to grow instead of get small. that's you Valve to piston clearance.
note this is with your cam pushrod and rocker arms installed.
OK here we go.
Years ago .040: was the Minimal clearance for Piston to Head Clearance that you should EVER HAVE! now .035 is comen.
Now i know that .040 was the "Safe" number because there is many many variables that would make a true minimal clearance
Such as Alu rod......would need more clearance
Standard steel rod would need more clearance then a stronger steel aftermarket rod.
Forged piston would need more clearance due to more expansion then Cast piston......
an old Heavy forged piston and stock rod would need more clearance do to extra weight or inertia Which also has to do with RPM
Which brings in another variable, Stroke. the more you have the more clearance you have to have.
Now, we have no idea, how high the previous owner revved this eng,
Now using all of the variables above. the only one that would require more clearance, would be the alu rod (of course) and a stroked eng(more than his 3.31 stroke)
Why did i write all of this?
I find it Very curious that his......OK maybe i wrote all of this for nothing!
I can't believe no one call me on my math mistake, above .053 head gasket -.020 piston pop up is NOT .013"
It's .033
going back to edit previous post.
I was getting real excited about us, being able to have as tight, of a quench as .013"
Years ago .040: was the Minimal clearance for Piston to Head Clearance that you should EVER HAVE! now .035 is comen.
Now i know that .040 was the "Safe" number because there is many many variables that would make a true minimal clearance
Such as Alu rod......would need more clearance
Standard steel rod would need more clearance then a stronger steel aftermarket rod.
Forged piston would need more clearance due to more expansion then Cast piston......
an old Heavy forged piston and stock rod would need more clearance do to extra weight or inertia Which also has to do with RPM
Which brings in another variable, Stroke. the more you have the more clearance you have to have.
Now, we have no idea, how high the previous owner revved this eng,
Now using all of the variables above. the only one that would require more clearance, would be the alu rod (of course) and a stroked eng(more than his 3.31 stroke)
Why did i write all of this?
I find it Very curious that his......OK maybe i wrote all of this for nothing!
I can't believe no one call me on my math mistake, above .053 head gasket -.020 piston pop up is NOT .013"
It's .033going back to edit previous post.
I was getting real excited about us, being able to have as tight, of a quench as .013"
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Moparman1806
Well-Known Member
Yes, I agree that flycutting the pistons will give a bunch more valve clearance. The thing that still would concern me is the piston to head clearance being too tight with the closed chambers without running a really thick head gasket. An over rev situation could be catastrophic without that space. Also too much space creates that much more length for pushrods , brackets, etc. That is why I suggested the proper heads, and all those issues are eliminatedNo picture but if you look at your picture, you can see where the valve smashed down on the piston, but there was no mark in the actual valve pocket. that shelf keeps the deeper valve pocket form being used. they are hitting the 90 degree shelf first.
If you grind of that shelf so it is the same angle as the valve pocket, you just gained, (as i keep saying
Latter i will look up my old valve to piston clearance and share them with you, to show the difference it made.
Have to find my notes first.
Earlier i said to us a cut of wheel to do the job. Have changed my mind. us a die grinder and a alu bit or a sand paper roll on a die grinder. make sure you clean up any sharp edges. you could even replace the die grinder for a drill for that matter.
He is not really fly cutting the valve reliefs in, or even deeper. The valve relief hits a wall and then has to go straight up to meet the top of the piston. sorry don't know how to explain it any better. I don't know why they do that on that piston, but it's been that way for some 20 + years. If you need the valve clearance, that piston was not designed properly for that purpose. Personally i think they did it to gain some compression, but i'm only guessing.
just my opinion here but if you never plan to rev the 340 past 5500 and you square deck the block. (estimating here) your highest pop up will be around .022-.053 head gasket=.031 piston to head clearance.If this engine ever sees 5500 hundred RPM it won't be with me pushing the pedal and if it does happen than I can assure you the title will have already been transferred
Maybe someone will verify that they have ran that tight of clearance.
Think i would still go with a .058-.060 head gasket.
Would you re measure your head gasket and find the thickest part on it. is it really .053 thick?
I did measure the old gasket and I got .050/.051
I dont plan to have the block decked and squared anymore.
I plan to take care of the truck/engine, not saying I wont hit the gas cause for sure I will but Im not going to push it. I plan to drive it to shows/weekends sometimes, nice weather.
Not counting on it for anything really other than showing it off.
No idea whatsoever. I want what everyone else wants, a nasty sounding cam and great driveability out of a 6 thousand pound brick
Torque and the lumpiest cam I can get away with without sacrificing too much other stuff.
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