Where to find thin .030 or less head gaskets for 4.070 bore

-
autoxcuda

autoxcuda

Well-Known Member
Joined
Apr 6, 2007
Messages
8,838
Reaction score
3,793
Looking for some thing under .030 head gaskets for my 416 build that will only be 10.2 to 1 or so compression.

Most sites list the P4120094 .028 compressed gaskets at 4.06 bore, which will not work for me. But some list that as 4.125 bore which I think is incorrect. ??

What about these Detroit gaskets I see on E-bay. They seem reasonable except for the ridiculous $20 shipping charge...

http://cgi.ebay.com/ebaymotors/ws/e...r_id=189171085515&ua=WVI7&itemid=380234632604

Is there another source for these Detroit 4.125 bore gaskets? Is this seller misrepresenting a set of P4120094 gaskets??
 
those are the P4120094

at least the ones in the picture are

i just measured a set...they are not 4.06 ...more like the 4.125
 
Get ahold of Cometic. They will make you anything you want but they are not cheap. Keep in mind that you will need a minumum of .035 piston to head clearance, so if you are a building a stroker, you may as well have it decked for zero deck and use a .035 to .040 gasket.

Granted, some will go with a tighter quench, I personally know of someone who runs .028" P to H clearance, with H-Beam Carillo rods on a BB stroker and swears that at 7K rpm "the piston just kisses the head". This guy knows his stuff and this is not street and the engine gets torn down every season.
 
70aarcuda said:
those are the P4120094

at least the ones in the picture are

i just measured a set...they are not 4.06 ...more like the 4.125
Click to expand...

Thank you very much. So you think if I order a set currently I'll get the 4.125 bores?

Wouldn't be the first time the MP book was wrong. New one says up to 4.060 bore too.

http://chucker54.stores.yahoo.net/mopenupto40b.html says,
" MOPAR - "A" engine - up to 4.060" bore (Composition Material)
(0.024" to 0.028" compressed thickness)

(sold as a set)
$35.95
MOPP4120094"
 
ramcharger said:
Get ahold of Cometic. They will make you anything you want but they are not cheap. Keep in mind that you will need a minumum of .035 piston to head clearance, so if you are a building a stroker, you may as well have it decked for zero deck and use a .035 to .040 gasket.
Click to expand...

P4120094 with the measured 4.125" bore will put me at my target compression. I need a set of head gaskets anyway. Cometic is overkill for what I'm doing.
 
You want the larger bore gasket anyway. The last thing you want is any gasket in the bore and it gives you room to notch the cylinder and head to unshroud the intake.
 
autoxcuda said:
P4120094 with the measured 4.125" bore will put me at my target compression. I need a set of head gaskets anyway. Cometic is overkill for what I'm doing.
Click to expand...

No problem. :read2: I thought you might be road racing given your history here. 8) Decking is pretty cheap compared to custom Cometics too.
 
ramcharger said:
You want the larger bore gasket anyway. The last thing you want is any gasket in the bore and it gives you room to notch the cylinder and head to unshroud the intake.
Click to expand...

Absolutely. We matched/scribed the heads to the bores and did a little chamber unshouding for the valves.

No problem. I thought you might be road racing given your history here. Decking is pretty cheap compared to custom Cometics too.
Click to expand...

Oh, it will be out at the track. Down those two long straights at Willow Springs at 5000-5500 rpm.

I'm not that far off target. We gained some CC's after the unshrouding and cleanup next to the spark plugs.

Pic #2 is after matching to the bore scribe.
 

Attachments

  • 12_9_10sm08.JPG
    96.4 KB · Views: 311
  • 12_22_10Sm5.JPG
    133.3 KB · Views: 325
Very nice AutoX! You sure Cometics aren't worth the price for what you have planned? I'm sure you know the head and deck would need to be finished to 50ra. :)

Here's a little hemi roadracing that I'm sure you've probably already seen....

[ame="http://www.youtube.com/watch?v=x13C7-NGneY&feature=related"]YouTube - Hemi Challenger at 2009 VIR Hankook Ultimate Track Car Challenge UTCC - 1:53:65 lap[/ame]
 
Here's another

[ame="http://www.youtube.com/watch?v=7D4dpsC8eVE&feature=related"]YouTube - Ferrari vs. Dodge Hemi Challenger[/ame]
 
ramcharger said:
Very nice AutoX! You sure Cometics aren't worth the price for what you have planned? I'm sure you know the head and deck would need to be finished to 50ra. :)
Click to expand...

I gotta follow a budget. I still need some new rims and tires. And a good set of Brembo or Willwood front brakes would be nice.

We matched the intake and exhaust too. The intake and heads have corresponding punch marks to line them up perfectly when re-installed too.
 

Attachments

  • 11_20_10Sm01.JPG
    90.2 KB · Views: 263
  • 11_20_10Sm02.JPG
    90.3 KB · Views: 271
Here's a little hemi roadracing that I'm sure you've probably already seen....

YouTube - Hemi Challenger at 2009 VIR Hankook Ultimate Track Car Challenge UTCC - 1:53:65 lap
Click to expand...

Glenn Bunch's car is pretty insane. Don't think there is much Challenger left though. Pretty much a Hemi in an custom race car chassis.

We have something called Spring Fling Speed Festival that is about 40 Mopars with about half pre '75's. Street cars, Nascar Hemi Daytonas, 440 Daytonas, Vintage Trans Am, turbo Rampage FWD pickups, Dakota pickups, you name it! It's the Thursday before Spring Fling show.

Jess Neal with the black 71 Cuda from Colorado has come out. He's run it at Pikes Peak.

[ame="http://www.youtube.com/watch?v=72p5vVwjRkk"]YouTube - 2007 Mopar Speed Festival Montage - Part 1[/ame]
 
autoxcuda said:
I gotta follow a budget. I still need some new rims and tires. And a good set of Brembo or Willwood front brakes would be nice.

We matched the intake and exhaust too. The intake and heads have corresponding punch marks to line them up perfectly when re-installed too.
Click to expand...

Well done! You're doing the best you can with the money you have , now bend the rules, lol! :snakeman:

I wish you the best on your upcoming season and please let me know if there is anything I can do to help. Brembos would be key.... If I had any rolling around I'd let you know but even then they would be for a Ducati.
 
ramcharger said:
BTW, Pikes Peak is MAJOR! Jeff must have balls of steel, lol!
Click to expand...

Jess is from Colorado Springs.

[ame="http://www.youtube.com/watch?v=NExAKxXl2Nk"]YouTube - 2008 PPIHC - Car 42 - Plymouth Barracuda - Part 2[/ame]

I guess he's been to a show in Denver: [ame="http://www.flickr.com/photos/mike_rogers/4143238668/"]Jess Neal - 1971 Cuda | Flickr - Photo Sharing!@@AMEPARAM@@http://farm3.static.flickr.com/2589/4143238668_7c9b39220b_m.jpg@@AMEPARAM@@4143238668@@AMEPARAM@@7c9b39220b[/ame]
 
ramcharger said:
At a 171 or so, he's only at 6k rpm. Incredible. Got to love Mopars!
Click to expand...

That's why I went stroker. Save the valvetrain on a car I still have to take to the grocery store.
 

Attachments

  • 12_9_10sm02.JPG
    111.3 KB · Views: 253
ramcharger said:
Well, that explains it, lol! :cheers:

I'm going to post a race up the "hill" on the general forum.
Click to expand...

They must have a whole vintage class at Pikes Peak. Google Jess Neal Cuda and you get all kinds of pics and some of the other old cars too.
 
jefflock said:
I bought a pair of ebay from John Wolfe out of Colorado. He is a good person to deal with and his store is Mopar Madness. Here is a link to the gaskets.
http://cgi.ebay.com/ebaymotors/MOPA...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
Click to expand...

Were yours packaged at part number P4120094 ?

Those are the ones I was looking at. But he charges $39 for the gaskets then $19 to ship!! That ad makes it seem he has something different than the P4120094, but sure seems from 70aarcuda that those actually are P4120094.

Mancini is like $35 for P4120094 with regular UPS ground shipping.
 
AutoX has your deck been re-surfaced? I ask because I have always heard to run those thin gaskets the heads and deck better be real darn flat and I believe it cause I tried a set of the Mopar .028 gaskets on a deck that sure looked flat to me with my straight edge yet one of the gaskets leaked. The heads had been re-surfaced so I know they weren't the problem. After the Mopar gasket leaked I pulled it apart and again checked the head and block for flatness and just as before they looked real good (no more than .001"). I put a set of Fe-Pro's on and haven't had a problem since. I can totally understand the money issue but down time costs money too.

BTW: the cheapest place I've found Cometic gaskets is from FBO. $140 a set for a SB.
 
fishy68 said:
AutoX has your deck been re-surfaced? I ask because I have always heard to run those thin gaskets the heads and deck better be real darn flat and I believe it cause I tried a set of the Mopar .028 gaskets on a deck that sure looked flat to me with my straight edge yet one of the gaskets leaked. The heads had been re-surfaced so I know they weren't the problem. After the Mopar gasket leaked I pulled it apart and again checked the head and block for flatness and just as before they looked real good (no more than .001"). I put a set of Fe-Pro's on and haven't had a problem since. I can totally understand the money issue but down time costs money too.

BTW: the cheapest place I've found Cometic gaskets is from FBO. $140 a set for a SB.
Click to expand...

My decks have been freshly machined. The heads are new Edelbrocks.

Fishy68, do you remember the bore size of the P4120094 gaskets you used? Where they orange or white?

I think this guy on E-bay is just selling the P4120094 .

70aarcuda has gaskets from MP that look the same and measure the same. His P4120094 measure a different bigger bore than the MP catalog says they should have.
 
The ones I have are white in color. When I go back to the shop I'll check them for part numbers and measure the diameter.
 
autoxcuda said:
My decks have been freshly machined. The heads are new Edelbrocks.

Fishy68, do you remember the bore size of the P4120094 gaskets you used? Where they orange or white?
Click to expand...

You should be fine then. I didn't have my block decked cause it appeared ok. That was probably my mistake now that I look back on it.

Mine were orange and since it's been about 3-4 yrs. I don't remember exactly how big the bore was but 4.18 comes to mind. I think I have another one of those gaskets around the shop somewhere. I'll look tomorrow and see if I can find it and let you know the exact specs.
 
You must log in or register to reply here.
-

Back
Top