head cylinder rebuild questions

[PwrSmoke]

which brings me to my next question,

i wont be using them on this engine, but have you ever used solid roller lifters in a diesel?
my rockers are adjustable, so simulating the preload will be quite easy.
maybe even modifying a old lifter i have to give me a fully pumped up condition.

Lots of diesels have solid lifters. Both my tractor diesel do. I don't know if any solids were made that will fit the IDI. Remember this lifter was originally designed for the 5.7L Olds diesel and used also in the 6.2L GM before it appeared in the 6.9L. Some research may yield a solid replacement but who wants to have to adjust valves?

 

[IDIoit]

im going to be building a hotrod this winter.
an M-37 with a 7.3 idi and twin hairdryers.
i dont mind adjusting valves, i do this on my boats all of the time anyways lol
but i wont be installing them on a daily driver.

 

[laserjock]

It wont hurt anything to face the extra off the valves, just hate to waste good metal.lol

I wondered about that. would 0.030" off the valve be too much? He does have a machine shop.

 

[IDIoit]

I wondered about that. would 0.030" off the valve be too much? He does have a machine shop.

that i do!
but i wont be doing them.
altho my K.O. Lee universal grinders are better than the valve machine the engine shop uses, i paid for the work.
they will redo it.
im set up with diamond tooling, and dressing Inconel valve will take precious material off my wheels.
and they are not cheap.

 

[typ4]

Well if the valve is .010 thicker then the seat vs deck is the biggest culprit, I would grind the valve face some and the seat face some. Im in fact doing this on a JohnDeere engine right now for the same reason, deck took .012 to clean.

 

[laserjock]

My ignorant non-machinist self would just chuck it in the lathe.

 

[typ4]

You dont want to disturb the valve head, dont know why ,but a machinist that has been building all types of BIG performance engines for near 50 yrs told me that, when he offers advice I shut up and absorb.

 

[PwrSmoke]

Yeah, if the seat was not done much, then an extra-thick valve must be the culprit.. taking into account the 0.015" loss on the head thickness. Simple enough to correct; grind the valve face to achieve the correct recession, then grind the tip to set the mounted height... done. Eight valves. An hour's work at most.

 

[IDIoit]

i need a lathe badly.
i don't have one yet, but most lathes are a 3 or 4 jaw chuck, you can actually damage the valve stem that way.
not to mention that when using a lathe you use a pointed carbide bit, which wont get you a good enough surface finish.
a grinding wheel is the way to do it.
and hold it in a collet.

me and my machinist have worked through issues before.
he's always made it right, and he wants to know the issue that's at hand to further his knowledge.
so i wont go up to him and say " the internet said this is wrong, can you fix it"?
i will be saying something along the lines of "the recession of X when at max lift hits Z with this measurement. with that measurement, we need the valve recession to be Y."

even tho you guys are f'n smart(*****), i need to go to him with facts and proof.
so, the next time he does one of these heads, (most likely my next project) he knows what works and what does not.

 

[IDIoit]

another thing i need to address is the 11/16 expansion plugs at the bottom of the head.

im thinking about taping them and pipe plugging them.

 

[PwrSmoke]

i need to go to him with facts and proof.

Are not the factory manuals with detailed specifications "facts and proof?"

Are not the AERA docs (which he may be subscribed to if he runs an auto machine shop) and other auto machine shop reference books "facts and proof?"

I don't think anyone here is yanking stuff out of their rectums. We are just relating well established specifications that are available from a multitude of sources... specs other machinists use when repairing IDI heads and specs we know work.

If there is no clever plan or reason for cutting the valve recession spec in half, it seems to me all that's being done here now is tap-dancing justify a mistake. Even if it turns out you have a few thousands clearance, what good reason is there to do this? Does it enhance the engine in any way, shape or form to run so close to the ragged edge? It will most certainly raise the compression a little but that is a two edged sword if the engine will have a turbo. I honestly can't think of anything that could remotely be called a "benefit."

Anyway, your engine, your choice and everyone's lesson whichever way it goes.

 

[IDIoit]

don't take it as a insult to your intelligence man, that is not what im trying to do.

i will not run these heads the way they are.

i want to do the piston to valve test for two reasons.

1) to further my education on these engine, as i still consider myself a rookie.

2) to SHOW my engine builder why they need to be at the specified dimension.

i soaked up every bit of information you guys have given me.
i will heed the warning.
if i wanted to blatantly disregard your advice, i would have already installed the heads, and purchased a reman...

im just trying to step up MY game

 

[icanfixall]

another thing i need to address is the 11/16 expansion plugs at the bottom of the head.

im thinking about taping them and pipe plugging them.

What is the idea doing this? How will you recess the plugs that are to be threaded into the heads? Leaving these plugs as they are seems a win win idea. If you choose to run 6.9 head gaskets on a 7.3 just open up the plugs as much as the coolant passage is in the 6.9 gaskets. BTW the openings in the 6.9 gaskets are not simply a round hole. I would make the holes in the plugs at least the same size or larger. Two small holes can pass more fluid than one large hole.

 

[typ4]

Im thinking you will find that the piston and valve chase each other at peak timing events pretty close. , if it clears by 60 thou, run it.

 

[IDIoit]

Lied through my teeth.

talking to my machinist today, and told him i performed a piston to valve clearance check.

"hay man, i have .015" gap inbetween the valve relief on the piston to the valve"

which, i did not, with my babys, i have not had any time at all.

to which he replied....

" you have WHAT??!!!
thats no good, bring the heads back and well make em' right"

as he opened the book and the spec calls for a .046-.060 recess.


"bring em back, well fix them"


EDIT: in regards to the facts post, i gave him governmental jive