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Re: will it be be absolutely necessary to mill the heads?
[Re: JohnRR]
#1173177
02/09/12 08:12 PM
02/09/12 08:12 PM
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Joined: Nov 2004
Posts: 340
Vitoria, Spain
Coke
OP
enthusiast
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OP
enthusiast
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Posts: 340
Vitoria, Spain
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Quote:
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 ?
Yes you´re right, i forgot the "L". 
No,i didn,t mean zero deck,I just think that i didn,t have a correct idea about what Quench is..
I was planning to use 95 oct gasoline.Here we have 95 and 98.
98 is more expensive but i,m not going to use the car as a daily driver..
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Re: will it be be absolutely necessary to mill the heads?
[Re: Coke]
#1173178
02/09/12 09:35 PM
02/09/12 09:35 PM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
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.
aren't 452's iron? What'd I miss? Some guys use steel shim gasket w/ alum heads..
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Re: will it be be absolutely necessary to mill the heads?
[Re: Mr.Yuck]
#1173180
02/09/12 09:53 PM
02/09/12 09:53 PM
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Joined: Jan 2003
Posts: 74,974
U.S.S.A.
JohnRR
I Win
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I Win
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Posts: 74,974
U.S.S.A.
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Quote:
Quote:
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.
aren't 452's iron? What'd I miss? Some guys use steel shim gasket w/ alum heads..
If you read up higher you would have seen we discussed this . About 5 yrs ago MP released a new alum head that I am pretty sure is NHRA legal, it's an Ebrock RPM with straight spark plugs and a freeze plug on the end , they call it the 452.
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Re: will it be be absolutely necessary to mill the heads?
[Re: JohnRR]
#1173181
02/09/12 10:43 PM
02/09/12 10:43 PM
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Joined: Sep 2005
Posts: 12,481
Chino Valley
RodStRace
I Live Here
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I Live Here
Joined: Sep 2005
Posts: 12,481
Chino Valley
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Quench = the area of the combustion chamber where the flat piston and the flat part of the head are. That would be the left side shown here, ignore the huge bump on the piston.  Octane Your 96 is equivalent to 92 here in the States. US octane is an average of 2 ratings, research octane (RON) and motor octane (MON). If you look at a gas pump in the United States, you will see a yellow sticker that says "octane by R + M / 2" which is the formula for the average. In Europe, they only report the RON.
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Re: will it be be absolutely necessary to mill the heads?
[Re: dogdays]
#1173182
02/10/12 06:32 PM
02/10/12 06:32 PM
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Joined: Nov 2004
Posts: 340
Vitoria, Spain
Coke
OP
enthusiast
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OP
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Posts: 340
Vitoria, Spain
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Quote:
These calculations based on 30 over 440, stock stroke, 84 cc head, flat top piston no valve reliefs nearest piston to deck is 0.068".
Mopar machine work wasn't the greatest and I'm betting your decks are not square to each other or parallel to the crankshaft centerline.
A 30 over 440 has about 914cc swept volume. We would like to have 10.5:1 compression with aluminum heads. To find the volume above the piston required for a compression ratio "r", divide by the quantity (r-1). 914 / 9.5 = 96.2cc. The head volume is 84cc so you need just 12.2cc more than the head. A normal 0.040" composition gasket is about 12 cc so you can see you need to delete some volume somewhere. The steel shim head gasket is 5 or 6 cc so let's say 6. Quite a few guys on this board have used them with success.
So your closest piston is 0.068 in the hole which equals 914 * 0.068/3.75 or 16.6 cc. I suggest cutting 0.035" down from the lowest corner so now all the pistons should be 0.033" down in the hole. You now have 914 * 0.033/3.75 or 8cc which plus the 6 cc of the head gasket and the 84cc head gives you 98cc. (914 + 98) / 98 = 10.3:1. I'd live with that. If you think about it you'll see that milling the block is twice as effective as milling a closed chamber head.
If you use just the steel valley pan/intake gasket with a smear of Hylomar around all the openings the intake should bolt on OK. Then all you have to worry about is valve to piston clearance.
Use checking springs with the valves on one cylinder and check the V/P clearance every 5 degrees from 20 BTDC to 20 ATDC and see what you get. One of the cam manufacturers has the procedure posted.
With 0.052" squish clearance your engine will run very well.
Good Luck!
R.
Thanks a lot Dogdays for all the work that this text involves.
Those formulas are very interisting and useful.
Couriosly ,is the typical theoricaly part that you find boring until you start to find troubles .
To mill the block sound even worse than mill the heads,however i,m starting to belive that this block could have been milled yet,cause i Googled the pistons part number(L2388) and i found a few posts wich talk about people who have used these pistons on 440 blocks and they sit even deeper than mine,such as 0.080 to 0.12 deck.
Last edited by Coke; 02/15/12 04:14 PM.
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Re: will it be be absolutely necessary to mill the heads?
[Re: Coke]
#1173183
02/15/12 05:48 PM
02/15/12 05:48 PM
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Joined: Nov 2004
Posts: 340
Vitoria, Spain
Coke
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Vitoria, Spain
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I have meassured the cylinder height from the top of the piston when it is in it´s lowest position in the hole(BDC) to the block surface and i got 3.858". 3.858"-0.070" deck = 3.788" Stroke? I was basing my comp calculations on the standard 3.750"... Am i doing it correctly? Thank again for your invaluable help (And I feel sorry for being so bore  )
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Re: will it be be absolutely necessary to mill the heads?
[Re: JohnRR]
#1173186
02/17/12 09:52 AM
02/17/12 09:52 AM
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Joined: Nov 2004
Posts: 340
Vitoria, Spain
Coke
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Vitoria, Spain
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I have measured the block height and there are 270mm (10.6299") between the crankshaft center and the block surface. I have read around here that a 440 block uses to have 10.725" so i suppouse that it has been decked.  Uploaded with ImageShack.us About the rod lenght i have meassured 180mm(7.086") from the center of the pin to the big end center,or the surface were it meets the bearing cap. This is what i don,t understand cause the workshop manual says that the are 6.766" to 6.770"??? The rod "I" beam has the number #1851535 stamped on it. Thanks i advance for any input.  Uploaded with ImageShack.us
Last edited by Coke; 02/17/12 11:48 AM.
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Re: will it be be absolutely necessary to mill the heads?
[Re: Coke]
#1173188
02/17/12 02:04 PM
02/17/12 02:04 PM
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Joined: Oct 2005
Posts: 8,861
Ontario, Canada
Stanton
Don't question me!
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Don't question me!
Joined: Oct 2005
Posts: 8,861
Ontario, Canada
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Quote:
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.
Ok, so if you don't get the same measurement for each piston what does that mean??
a) either the rods are unequal length
b) the piston comp. heights are unequal (not likely)
or
c) the decks are not even (most likely)
I would deck the block to get the decks even and straight and run the gaskets you have with the heads as they are.
People talk about milling the intake surface after milling heads but you rarely see anyone suggesting the same after decking a block! Well, decking a block .010 is no different that milling a head .010! But in your case, you're using a gasket which is .020 thicker than stock so in theory you can knock .020 off the "stock" deck measurement or off the head and you'll still be at stock height.
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Re: will it be be absolutely necessary to mill the heads?
[Re: JohnRR]
#1173189
02/17/12 06:05 PM
02/17/12 06:05 PM
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Joined: Nov 2004
Posts: 340
Vitoria, Spain
Coke
OP
enthusiast
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OP
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Vitoria, Spain
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Quote:
Seriously ??? A tape measure ?
the part number is a stock factory rod there is no way it is that long , you need to use something a little more PRECISE to measure that stuff.
The tape is not enough accurate for most things,i know,just something orientative.The trouble is that i can,t to meassure the rod center to center when it is installed .Just to the pin surface to one of the big end corners. This is why there are that big difference.
However knowing that the rods are the stock ones ,doesn,t work to spend more time meassuring them.
Anyway,the piston travel continues being 3.788"(This time using better than a tape tools ,as you can see in the pictures)
Uploaded with ImageShack.us
Uploaded with ImageShack.us
What i need to know is what meassure i have to use with the comp.ratio calculator, 3.750 wich is the ratio of one crankshaft turn,or 3.788" wich is the travel from BdC to TDC and it depends on piston comp height.
The CR changes depending on wich of both you are using.
Thanks again
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Re: will it be be absolutely necessary to mill the heads?
[Re: Coke]
#1173190
02/17/12 06:09 PM
02/17/12 06:09 PM
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Joined: Jan 2003
Posts: 104,346
Garden Grove, CA
OzHemi
Penguin-hating Ginger
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Penguin-hating Ginger
Joined: Jan 2003
Posts: 104,346
Garden Grove, CA
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Quote:
Off topic for a moment, but I used to have a Bultaco Sherpa T. 
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Re: will it be be absolutely necessary to mill the heads?
[Re: OzHemi]
#1173191
02/17/12 07:02 PM
02/17/12 07:02 PM
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Joined: Oct 2005
Posts: 8,861
Ontario, Canada
Stanton
Don't question me!
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Don't question me!
Joined: Oct 2005
Posts: 8,861
Ontario, Canada
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Quote:
3.750 wich is the ratio of one crankshaft turn,or 3.788" wich is the travel from BdC to TDC
Forget the 3.750. You've measured the piston travel at 3.788 and if that is accurate then that is the measurement you must use.
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Re: will it be be absolutely necessary to mill the heads?
[Re: Coke]
#1173195
02/18/12 10:04 AM
02/18/12 10:04 AM
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Joined: Jan 2003
Posts: 74,974
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,974
U.S.S.A.
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Quote:
Uploaded with ImageShack.us
What i need to know is what meassure i have to use with the comp.ratio calculator, 3.750 wich is the ratio of one crankshaft turn,or 3.788" wich is the travel from BdC to TDC and it depends on piston comp height.
The CR changes depending on wich of both you are using.
Thanks again
Did you check push on the piston to see how much it rocks when you are checking it like it is in this picture .
I haven't gone back and read the thread for your specs but I don't think you have too high a compression ratio to even be worrying about this if you are using alum heads .
What was the question again ?
Looking at the pictures the block has been decked , the .006 difference you are seeing is probably the tolerance stack ups. Do you have a good straight edge or have access to a machinists straight edge , check the block to see if it truely is wavy , I'm guessing it's not that bad.
If Hughes says you need higher compression ratio to use their cam and you want to run the engine the way it is then get a different cam. Contact member fast68plymouth and get a cam from him .
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Re: will it be be absolutely necessary to mill the head
[Re: dogdays]
#1173196
02/18/12 10:07 AM
02/18/12 10:07 AM
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Joined: Jan 2003
Posts: 74,974
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,974
U.S.S.A.
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Quote:
The 535 rod is the stock 413/440 rod that is 6.768" C-to-C.
What undersize are your rod bearings?
To increase stroke by offset grinding you have to end up with a smaller rod journal. Unless you are running 0.040" undersize rod bearings I doubt the stroke differs from the standard 3.750.
I think there are a lot of measurement errors that are confusing you.
R.
It is possible for the stroke to be off by that much , the crank in my 383 is 3.370 when it should be 3.375, it is cut .010 under so I don't know who shortened it, the factory or ? The plus side is my pistons ended up at zero deck instead of poking out of the block.
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