yes. cool thanks!

 

Can anyone tell me if the exhaust studs are threaded in or maybe pressed in on the 400cid heads

 

They should be threaded in, I believe the 400 were threaded in too.

Good luck, I got all but one out when I pulled mine. Also you will most likely find that they go into the water jacket.

 

Do every single one of them go into a water jacket because i have one busted off and am trying to drill it out but do not want to drill into the head.

 

Yes in my heads they did.

 

When i took my head to the machine shop to ask if the head was salvageable, i asked a ton of other guestions and got mamy answers the one i do not understand is: what does "hang the pistons mean" I didn't want to ask what it meant cause the guy seemed in a hurry.

 

I personally never heard the term before,"hang the pistons", what context did this come up in ?

ps: Wait till ya break an easy-out off in a head, ah...the learning curve.

 

There is an easy out and a hardened drill bit in mine, that's why its in my shed sitting.

The only thing I can think of is relating to the travel of the piston, I believe some pistons actually come out of the block and into the head a bit, as when calculating cubic inches that is a factor.

 

I broke one off once, brutal freakin nightmare, I bought this armour piercing drill from skf, got the job done but I know I never wanna go through it again.
Ya as far as the piston hang thing, fer sure some high comp. ones travel above deck height a bit, I just have never heard the term before, I'd love to know what that machinist meant by it though.

 

I was asking what all they do if i bring the engine and engine parts in, he said the glass bead the parts to get it to bare cast iron and then check everything and install the cam bearings and then he said we do hang the pistons. bunch of bla bla after that. I think i will go and ask them what that means.

 

SWEET! I was able to remove one of the broken studs on one of the heads ran a tap through it just to clean up the threads!

QUESTION does it matter that the new studs have a course thread pitch versus the original fine thread pitch. I can just find nuts that will thread onto the new studs right? hopefully

 

my heads as well. Made it easier knowing i was only drilling into a water jacket rather than par of the head.

 

Improving that learning curve everyday

 

I ran bolts in mine rather then studs, but there should be no problem as long as you put the right nut on the stud.

 

Ok I was in the process of removing the last broken stud and got a little carried away with the drill and got into the threads a little i was wondering if it will be ok or do i need the machine shop to properly fix it. I ran a tap through it it seems to hold the stud but maybe it might leak.

 

 

Its possible to re-drill/ re-tap for a bigger stud, but check with your machinist. It's hard to see from here, but you should be fine bro.

 

All the bigblock heads after 1972 had hardened seats. some 72's also. [a few]. 71 and earlier heads are not hardened. Peferect circle seals are a good idea, more preferably on the intake valve [this is due to the vacuum; more of it on the intake stroke]. The exhaust valve needs a little more oil so sometimes the valve seal is left off the exhaust side {due to fact that there is little vacuum and more heat on the exhaust valve stem} If your seats are "sunk-in" [the valve sits too low in the chamber due to wear] then you might want to replace the valve seats {think $$}. Chrysler went to the hardened seats due to the EPA's {i think} mandate to eliminate lead from gas {which had acted as a lubricant for the exhaust valve seat.} The lead in the gas had helped to prevent the valve seat from excessive wear and also acted as an inexpensive octane boost. So, hardened seats and lower comp. were the norm as the 70's went bye. The lower compression was needed also to help the engine burn cleaner {at least that was the thought back then.} All of the bigblock heads after 67 flowed about the same flow so the compression issue is the only hang-up with the later ones. {the port floor was a little lower on the later heads}
452 heads can be made to work very well with a mild bowl port and port matching the intake to the head. The 400's were low on the compression ratio. In 73 they only had 8.2:1, so finding some pistons that come up higher in the bore can really help. ENJOY!!!

 

I was thinking that. When i turned the stud all the way in there is a slight and i mean slight bit of play it wobbles in the hole ever so slightly i was thinking that the teflon or rtv or what ever i use will take up that slack. Does anyone agree?

 

What is a bowl port mean?

 

If you remove the valve, the area under the head of the valve is the "bowl" , just generally smoothing all the transitions from the valve seat area to the beginning part of the port itself and maybe trimming the valve guide boss a bit would be considered a mild bowl porting {aka; blending the bowl} just smooth out the obvious rough edges so they flow better, your not removing alot of material, just improving the contours. The high dollar porting is done in conjuction with a high dollar flow measuring device. Obviously, you cant do that yourself but you can make some improvements by blending the obvious sharp edges {youll see 'em if you pop the valve out.

And yes, some good quality RTV should work on your stud problem, carefully torque that nut on that one, if it pulls out, then you can drill bigger and tap, You may have to drill exhaust manifold also, {maybe not though??} one tip; use the exhaust manifold itself as a drill bit guide

 

Use the copper rtv on all studs to prevent any leaks.

 

i assume any parts store carries that or is that a performance store item only?

 

If it's not in a water jacket you could Heli-coil it. I wouldn't use teflon or rtv. That's just me though, thats not to say it wouldn't work. Think about when the head gets hot, that bit of play you feel now will be worse at temp.

 

The copper rtv should be at any parts store, and it is I believe the highest temp rating and is recommended by everyone I talked to except my mechanic who is old school and he recommended boiler putty. I have an unopened tube I got lying around somewhere I never used, will look at what its rated at if I can find it.

 

Cool thanks for the info.

 

I am looking at our performance catalog and they have for the big blocks a complete assembled head made out of aluminum 84cc chamber 2.14/1.81 valve size 25Lbs/ weight head for me little over $700 plus tax probably more. Is that a good deal?

It also says in the description "straight spark plug design" what does that mean are the plugs straight in like on the Hemi's?

What does CNC-ported mean?

 

The Edelbrock heads I have the spark plugs are on an angle, they say that it is more efficient with the angled plugs.

 

I think your asking where i am getting that price? It is out of the MOPAR performance catalog. It is my employee discount. Part# P5153524