head chamber volume measurement

[stage3]

hi guys.
just measured the chamber volume on my #518 max heads with the comp cams cc kit..it came in at 88 cc's,after measuring twice,,according to my old spec sheets its supposed to be 82-87...these appear to have never been decked....

wouldn't that put like the 906 and 452's at around 94?just asking because I need to order some pistons soon and want to be sure I did not screw this up...its pretty straight forward though...grease the head surface,,apply plate..torque the spark plug(new),,turn valve to release green windshield wash fliud..tilt head to move air bubble to top...see measurement....
what do u think..thanks.

 

[493 Mike]

Sounds like you covered all the bases on checking chamber volume.
Mike

 

[Cranky]

All the uncut open chamber factory heads I've measured (906, 452 etc) came out right around 90 CC but usually they vary and have found heads that vary on the same head. I also use transmission fluid. If you're using a clear plastic plate to seal the chamber, you could have two holes in it. One for fill and one to let the air out.

 

[lewtot184]

generally the 906's will be 88cc and the 452's 90cc. the 452's will usually have one chamber on the end of the head that is deeper than the other three.

 

[dvw]

I was told that back in the day NHRA offices had a fire. They lost there record keeping of engine dimensions. When they called Chrysler the race group was a little lets say "creative" with the volume numbers they supplied.
Doug

 

[not so famous bob]

I was told that back in the day NHRA offices had a fire. They lost there record keeping of engine dimensions. When they called Chrysler the race group was a little lets say "creative" with the volume numbers they supplied.
Doug

alcohol w/ trans fluid for color. easier clean up.

 

[Cranky]

generally the 906's will be 88cc and the 452's 90cc. the 452's will usually have one chamber on the end of the head that is deeper than the other three.

I've found some 906's at 88 and they were as far as I could tell, never off the block before. And on one chamber being bigger on the 52's, I found smaller on one end before. Go figure lol. Would imagine that whoever was doing the molds wasn't that concerned with being off a couple of CC's but it is kinda odd one on the end be different with the others being the same. Maybe they did it on purpose for some reason?? A friend of mine worked on the lines back in the day....heck, his whole family worked for Chrysler back then and I've heard some crazy stories from them lol.

 

[lewtot184]

I've found some 906's at 88 and they were as far as I could tell, never off the block before. And on one chamber being bigger on the 52's, I found smaller on one end before. Go figure lol. Would imagine that whoever was doing the molds wasn't that concerned with being off a couple of CC's but it is kinda odd one on the end be different with the others being the same. Maybe they did it on purpose for some reason?? A friend of mine worked on the lines back in the day....heck, his whole family worked for Chrysler back then and I've heard some crazy stories from them lol.

it's my understanding that the worst american cars (all makes) built were late '70's. ironically i have a set of '452's that have much better port casting than the edelbrock rpm's i'm using on one engine. never know what you got until you take it apart.

 

[66Satellite47]

I've found some 906's at 88 and they were as far as I could tell, never off the block before. And on one chamber being bigger on the 52's, I found smaller on one end before. Go figure lol. Would imagine that whoever was doing the molds wasn't that concerned with being off a couple of CC's but it is kinda odd one on the end be different with the others being the same. Maybe they did it on purpose for some reason?? A friend of mine worked on the lines back in the day....heck, his whole family worked for Chrysler back then and I've heard some crazy stories from them lol.

I did quite a few sets of 906's that were virgin as far as I could tell. They were all right around 88 cc before any milling. A few did have chambers that varied maybe 1-2 cc's. It did take a fair amount of milling to get them down to NHRA "minimum". As I recall the 346's & 452' were about 90 - 92 stock. My recollection on Max Wedge heads is 88 cc was the NHRA number, but sure could be wrong.

 

[stage3]

the interesting thing here based upon what u guys r saying,,these #518 heads are closed chamber,just like the 915's and 516's.,, heads r the same cc volume as the open chamber 906/452's box stock...

a guy would have to mill the heck out of them to get them down to the minimum of 82...that's not going to happen,im glad I measured these,,diamond can make the pistons custom fit instead..

 

[lewtot184]

if i remember correctly the '64 stage III casting has a larger chamber than the '62-'63'. there were some machined chamber mods for the stage II head and that mod was cast into the '64 head. i believe this was an unshrouding of the intake valve and also part of reducing the comp ratio from 13.5 to 12.5.

 

[66Satellite47]

if i remember correctly the '64 stage III casting has a larger chamber than the '62-'63'. there were some machined chamber mods for the stage II head and that mod was cast into the '64 head. i believe this was an unshrouding of the intake valve and also part of reducing the comp ratio from 13.5 to 12.5.

Yup, looked it up & the '64 heads had a larger chamber (86 cc per NHRA, about 82 for the earlier heads).

 

[747mopar]

hi guys.
just measured the chamber volume on my #518 max heads with the comp cams cc kit..it came in at 88 cc's,after measuring twice,,according to my old spec sheets its supposed to be 82-87...these appear to have never been decked....

wouldn't that put like the 906 and 452's at around 94?just asking because I need to order some pistons soon and want to be sure I did not screw this up...its pretty straight forward though...grease the head surface,,apply plate..torque the spark plug(new),,turn valve to release green windshield wash fliud..tilt head to move air bubble to top...see measurement....
what do u think..thanks.

I CC'd my 452's, they were 88.

 

[stage3]

brain fart,,whoops..

the old lit I have is for the 63 heads..not the 64's...they did have a smaller chamber..i cannot measure my 63's because there in the car bolted to a running motor..

 

[Cranky]

it's my understanding that the worst american cars (all makes) built were late '70's. ironically i have a set of '452's that have much better port casting than the edelbrock rpm's i'm using on one engine. never know what you got until you take it apart.

I think Chrysler was getting bad quality control around 72-73 and got worse in the late 70's just before they negotiated their loans. They were dying for sure but I didn't particularly like anything they had from the 80's either.

the interesting thing here based upon what u guys r saying,,these #518 heads are closed chamber,just like the 915's and 516's.,, heads r the same cc volume as the open chamber 906/452's box stock...

The 516's and the 915's averaged 10cc less than the open chambered heads. Don't remember CC'ing anything else....

 

[stage3]

just found my 64 tech spec sheets...

64 heads r 86-92 cc's
62-63's are 82-87 cc's...

so at 88 mine r right there..they came off an a/sa car so the 2+ cc's over minimum were the safty zone...

didn't realize 64 max heads were so close to the 906/452's in chamber volume..as in the same size and similar compression ratio if 1 was using the same piston in each..

 

[Budnicks]

old Mopar Muscle article 1998 IIRC
make sure to click on the photos tabs
& check out the tech stuff & spec.'s
good info

Cylinder heads part 1
http://www.hotrod.com/articles/cylinder-heads/

another good one for people wanting better performance
Mopar Muscle Mag. tests
http://www.hotrod.com/articles/mopps-1205-big-block--cylinder-head-flow-testing/

it's not really combustion chamber volume specific
just good info, if you don't know

I've had untouched org. heads
that varied 4cc from what was allegedly supposed to be
in different castings 906 452 915 516 etc.
the open chamber heads seemed like were more prone
to variances in Combustion chambers CC Volumes
larger surface area quench etc.
types of valves & shapes can & will effect the cc/volumes too
or even how deep the seats have been cut etc.

good luck

 

[Ski 61701]

Another thing to check for on the 518 heads is valve seat recession, hence the larger cc measurement. I had a set of heads and my measurements were 86 to 90cc. Looked at the valves and noticed a few were receded into the head. Another thing to look at are the valves oem mw or were they replaced. OEM valves were tuliped and that will affect cc volume in comparison to current valve design

 

[stage3]

thanks guys,,
the valves r not sunk in the heads at all..in fact if I had to guess since they still have the springs on them that corda ran,,I would say either they were new or he had new seats installed..where as the valves sit on top of the seats slightly into the combustion chamber...espeasialy the exhaust valve...they do have bronze guides.. just mocked up the set up on my 426 marine block with indy tunnel ram or I would provide a pic...

 

[Dibbons]

I migh