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will it be absolutely necessary to mill the heads? #1173157 02/06/12 09:01 AM 02/06/12 09:01 AM
Joined: Nov 2004 Posts: 340 Vitoria, Spain C Coke OP enthusiast
Coke OP enthusiast C Joined: Nov 2004 Posts: 340 Vitoria, Spain	Hello everybody, I have a set of new MP 452 heads in the box(84cc chamber)for my 440 engine. Using a comp calculator i would get a comp ratio of 9.30 with a .039" gasket. Well, i sent a mail to Hughes for ordering one of their whisplash cams,and they said to me that 9.30 is too low for aluminium heads and i will need to mill the heads 0.50 or 0.60.. Also said that a .020 gasket is not an option for alu heads. I,m not very happy about that idea...troubles with the intake fitment,valve clearances etc... What is your opinion? Thanks a lot in advance for any input. Last edited by Coke; 02/13/12 04:11 PM.

Re: will it be be absolutely necessary to mill the heads? [Re: Coke] #1173158 02/06/12 09:23 AM 02/06/12 09:23 AM
Joined: Jan 2003 Posts: 74,942 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,942 U.S.S.A.	I don't think you'll have a valve clearance issue unless you have a flat top at zero deck with no valve reliefs but with that low a compression to begin with it sounds like your pistons are not near the top ? If the person cutting the heads knows what they are doing intake fit is not a problem. for every .010 off the deck surface you cut .0123 off the intake side of the head and the intake fits fine . How is the gas where you are ?

Re: will it be be absolutely necessary to mill the heads? [Re: Coke] #1173159 02/06/12 09:26 AM 02/06/12 09:26 AM
Joined: Mar 2010 Posts: 1,880 Out in Left Field, NY B bobs66440 top fuel
bobs66440 top fuel B Joined: Mar 2010 Posts: 1,880 Out in Left Field, NY	I am building a 440 using Stealth aluminum heads and 9.35:1 compression and a Summit 6401 cam. I have run the combination by all the manufacturers involved and many here and no-one has said I can't do it (though my combination isn't optimum, long story). As far as gaskets go, some have run .020" steel shim gaskets with aluminum heads successfully by coating them, though 440 Source warned against it. I am using .027" Cometic multi-layer stainless gaskets that are ok for aluminum.

Re: will it be be absolutely necessary to mill the heads? [Re: Coke] #1173160 02/06/12 11:35 AM 02/06/12 11:35 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	I'd have the heads' deck milled then set the heads on head gaskets on the block then mockup/set the intake and its' gasket on there & see how far the port/bolt hole alignment is off then another trip to the machine shop to have the heads' intake faces' milled. It's not easy but later on when done & frying the tires cause you got every sub system dead on or near dead on (depending on the system) you'll have forgotten about the time/effort/occaisional aggravation that it took to get you there live every 24 hour block of time like it's your last day on earth

Re: will it be be absolutely necessary to mill the heads? [Re: Coke] #1173161 02/06/12 01:42 PM 02/06/12 01:42 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	What planet are we on? Someone help me out here...the only Mopar 452 heads with which I am familiar are cast iron stockers from the late '70s, usually 90 - 92 cc chambers. I've never associated that number with aluminum heads. If the refrigerator magnet sticks to them they are cast iron. In that case 9.30:1 is a very usable compression ratio for pump gas. R.

Re: will it be be absolutely necessary to mill the heads? [Re: dogdays] #1173162 02/06/12 01:49 PM 02/06/12 01:49 PM
Joined: Jan 2003 Posts: 74,942 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,942 U.S.S.A.	Quote: What planet are we on? Someone help me out here...the only Mopar 452 heads with which I am familiar are cast iron stockers from the late '70s, usually 90 - 92 cc chambers. I've never associated that number with aluminum heads. If the refrigerator magnet sticks to them they are cast iron. In that case 9.30:1 is a very usable compression ratio for pump gas. R. EARTH ... MP sells an NHRA stock legal head called the 452 , it's an Ebrock head with straight plugs and a freeze plug in the slab ended head. Since NHRA was allowing outer makes to use it in stock they finally allowed Mopar one also.

Re: will it be be absolutely necessary to mill the heads? [Re: JohnRR] #1173163 02/06/12 03:31 PM 02/06/12 03:31 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	Well, I'll be dogged! R.

Re: will it be be absolutely necessary to mill the heads? [Re: dogdays] #1173164 02/06/12 03:53 PM 02/06/12 03:53 PM
Joined: Jan 2003 Posts: 74,942 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,942 U.S.S.A.	Quote: Well, I'll be dogged! R. They have been out for a couple years now , but you have been away from the site ...

Re: will it be be absolutely necessary to mill the heads? [Re: bobs66440] #1173165 02/06/12 04:40 PM 02/06/12 04:40 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	I would run a .020 shim gasket and coat it with permatex copper spray and run it. Or do a cometic .027 gasket. Those whiplash cams are designed for low cr engines, and you've already got way more CR than what hughes claims their whiplash cams are designed for. You probably just talked to someone who still believes in that whole aluminum lowers compression wives tale.

Re: will it be be absolutely necessary to mill the heads? [Re: DaytonaTurbo] #1173166 02/06/12 06:21 PM 02/06/12 06:21 PM
Joined: May 2003 Posts: 6,558 Downtown Roebuck Ont Twostick Still wishing...
Twostick Still wishing... Joined: May 2003 Posts: 6,558 Downtown Roebuck Ont	Quote: I would run a .020 shim gasket and coat it with permatex copper spray and run it. Or do a cometic .027 gasket. Those whiplash cams are designed for low cr engines, and you've already got way more CR than what hughes claims their whiplash cams are designed for. You probably just talked to someone who still believes in that whole aluminum lowers compression wives tale. Provided he has the piston to head clearance. If it is a zero deck engine .020-.027 could be flirting with disaster. Kevin Last edited by Twostick; 02/06/12 06:21 PM.

Re: will it be be absolutely necessary to mill the heads? [Re: Twostick] #1173167 02/06/12 08:37 PM 02/06/12 08:37 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	So, I bet if he has to ask the question the pistons are at least 0.020" down in the hole... To the Original Poster, with the piston at top dead center (TDC) how far down in the hole is the piston? Give the answer in inches or mm, I'm OK with either. If it is more than 1/2mm or 0.020" you're OK with the steel shim head gasket assuming block and heads are flat. It is not recommended by the manufacturers, but quite a few people on this board have used them with aluminum heads and they work. Cheaper and easier than milling heads. Even if you decide to mill the heads, milling them 0.030" or 0.75mm should allow you to use the heads and intake without milling the intake faces. There is that much difference between the thickest and thinnest head gaskets in normal use. In my opinion I wouldn't do machine work to increase the compression ratio by 0.2. Your 9.3:1 is equal to or more than what any factory 440 actually had when it rolled off the production line. I would do machine work to get the piston to within 1mm or 0.040" of the head when assembled to get better squish. R.

Re: will it be be absolutely necessary to mill the heads? [Re: JohnRR] #1173168 02/06/12 09:58 PM 02/06/12 09:58 PM
Joined: Feb 2005 Posts: 4,310 Prospect, PA BSB67 master
BSB67 master Joined: Feb 2005 Posts: 4,310 Prospect, PA	Quote: Quote: Well, I'll be dogged! R. They have been out for a couple years now , but you have been away from the site ... Actually, over five years.

Re: will it be be absolutely necessary to mill the heads? [Re: BSB67] #1173169 02/07/12 02:12 AM 02/07/12 02:12 AM
Joined: Jan 2003 Posts: 74,942 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,942 U.S.S.A.	Quote: Quote: Quote: Well, I'll be dogged! R. They have been out for a couple years now , but you have been away from the site ... Actually, over five years. I'm screwed either way , I was going to say they have been out for a number or years and then second guessed my self expecting a ... actually they came out last year ...

Re: will it be be absolutely necessary to mill the heads? [Re: JohnRR] #1173170 02/07/12 08:33 AM 02/07/12 08:33 AM
Joined: Feb 2005 Posts: 4,310 Prospect, PA BSB67 master
BSB67 master Joined: Feb 2005 Posts: 4,310 Prospect, PA	Quote: Quote: Quote: Quote: Well, I'll be dogged! R. They have been out for a couple years now , but you have been away from the site ... Actually, over five years. I'm screwed either way , I was going to say they have been out for a number or years and then second guessed my self expecting a ... actually they came out last year ... Yeah, I did not mean it as nit-picking. When I read yours, I said to myself, "I think its three years", then walked over to my files. Man, the time sure goes, but I belive your point was simply ,...they've been around for a while...., and they certainly have.

Re: will it be be absolutely necessary to mill the heads? [Re: dogdays] #1173171 02/07/12 08:52 AM 02/07/12 08:52 AM
Joined: Nov 2004 Posts: 340 Vitoria, Spain C Coke OP enthusiast
Coke OP enthusiast C Joined: Nov 2004 Posts: 340 Vitoria, Spain	Thanks a lot for all the replies Dogdays, The pistons are flat ,stock style,TRW L2388,1.926" comp distance . The deck is not exactly the same in all the cyls,but they are between .068" wich is the one most closer to the surface and .074" that would be the most deeper in the hole. The Whiplash cam lift is .518". What i thought,or at least what i have read in some web page, is that the Alu heads subtract one pound from the compresion,but they compensate that loss of power in other ways. So if it is 9.30:1 would it go to 8.30:1? Here is a link to Youtube about a 66 Coronet wich is running a very similar set up,440 engine ,Whiplash cam and 452 heads.(The cast iron ones ?)The engine is from a motor-home,8.5 comp ratio and the owner seems to be very happy with it... http://www.youtube.com/watch?v=MjeCyVvg4Ss Last edited by Coke; 02/11/12 10:00 AM.

Re: will it be be absolutely necessary to mill the heads? [Re: Coke] #1173172 02/07/12 10:49 AM 02/07/12 10:49 AM
Joined: Mar 2010 Posts: 1,880 Out in Left Field, NY B bobs66440 top fuel
bobs66440 top fuel B Joined: Mar 2010 Posts: 1,880 Out in Left Field, NY	Quote: Thanks a lot for all the replies Dogdays, The pistons are flat ,stock style,TRW L2388,0.75" comp distance . The deck is not exactly the same in all the cyls,but they are between .068" wich is the one most closer to the surface and .074" that would be the most deeper in the hole. The Whiplash cam lift is .518". What i thought,or at least what i have read in some web page, is that the Alu heads subtract one pound from the compresion,but they compensate that loss of power in other ways. So if it is 9.30:1 would it go to 8.30:1? ] The guys here will correct me if I'm wrong, but I think it's not that aluminum lowers compression, but more like you can run more compression with aluminum than an iron head without detonation, all things being equal.

Re: will it be be absolutely necessary to mill the heads? [Re: bobs66440] #1173173 02/07/12 11:29 AM 02/07/12 11:29 AM
Joined: Jan 2003 Posts: 74,942 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,942 U.S.S.A.	Quote: The guys here will correct me if I'm wrong, but I think it's not that aluminum lowers compression, but more like you can run more compression with aluminum than an iron head without detonation, all things being equal. This is what everything points to . Coke , with pistons that deep in the hole you'll have no issues with piston to valve interference. but you'll want to be careful with compression being too high without the benefit of quench because of how deep they are in the hole.

Re: will it be be absolutely necessary to mill the heads? [Re: JohnRR] #1173174 02/09/12 08:28 AM 02/09/12 08:28 AM
Joined: Nov 2004 Posts: 340 Vitoria, Spain C Coke OP enthusiast
Coke OP enthusiast C Joined: Nov 2004 Posts: 340 Vitoria, Spain	Quote: The guys here will correct me if I'm wrong, but I think it's not that aluminum lowers compression, but more like you can run more compression with aluminum than an iron head without detonation, all things being equal. It seems that they dissperse the heat a lot faster than the iron,wich means that they would evite detonation on a 10:1 and upper CR,but i don,t know what would happen with the power on an engine with less than 10:1. Quote: Coke , with pistons that deep in the hole you'll have no issues with piston to valve interference. but you'll want to be careful with compression being too high without the benefit of quench because of how deep they are in the hole. John, Do you mean that the compression could damage the gasket triying to scape ?That is the explanation that i find,cause the quench is the flat part of the piston wich leves with the block surface,but this would be on a dish piston,six pack style for example. However 9.3 or 9.5:1 CR wouldn,t be a trouble,would it? Thanks both of you Last edited by Coke; 02/09/12 08:50 AM.

Re: will it be be absolutely necessary to mill the heads? [Re: Coke] #1173175 02/09/12 10:48 AM 02/09/12 10:48 AM
Joined: Jan 2003 Posts: 74,942 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 74,942 U.S.S.A.	Quote: Quote: Coke , with pistons that deep in the hole you'll have no issues with piston to valve interference. but you'll want to be careful with compression being too high without the benefit of quench because of how deep they are in the hole. John, Do you mean that the compression could damage the gasket triying to scape ?That is the explanation that i find,cause the quench is the flat part of the piston wich leves with the block surface,but this would be on a dish piston,six pack style for example. However 9.3 or 9.5:1 CR wouldn,t be a trouble,would it? Thanks both of you No the compression won't damage the gasket . Your compression ratio under 10 is fine as long as you don't run the lowest octane fuel available . I'm not getting your question , your english is generally good but I'm a little confused by the flat part of the piston wich leves with the block surface is that supposed to read the flat part of the piston which levels with the block surface ... meaning zero deck ?

Re: will it be be absolutely necessary to mill the heads? [Re: JohnRR] #1173176 02/09/12 03:01 PM 02/09/12 03:01 PM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	I believe Hughes told you that because the aluminum head can run about 1 point higher in comp to be equal with and iron head. So if you run 10.5 with the 452 aluminum head its like 9.5 with the cast iron head. I can tell you we milled the Eddy heads on my sons 400 .040 to get 10.8 comp. It does not have good quench but runs fine on 92 or 92 pump and it has no fitting problems as we milled the intake side .040 also. Sure you can run the comp at 9.5 but you will have a little better performance if you up the aluminum headed eng to 10.5. You will just loose a tad of power at 9.5. That said I run 10.6 in my aluminum headed 493 and it does have quench and runs great on 92 pump. Ron Last edited by 383man; 02/09/12 03:02 PM.

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