cylinder head instalation on 440.

[charger440]

Alright, my low compression 1975 440 is about to get a bit of an overhaul. The engine is stock internally so i assume it has about an 8.2:1 compression ratio.   I have a pair of 906 heads ported to 2.14 intake and 1.81 exhaust valves. They have also been decked .080. I have a Mr gasket steal shim head gasket that when compressed has a thickness of .018 - .020. and some copper gasket adhesive. Ive been told i wont have any intake manifold lineup problems or any pushrod problems with the heads being decked that much, is this right?... Ive also been looking at some cams and was hoping for some insight on one, Ive looked through the forum a bit about it and noticed the engle k54 was mentioned as being good for a low compression 440. I was also wondering a ball park figure of what my compression ratio would be with these new parts... and if u guys can see any potential problems or things i might of overlooked please let me know.  Being a young guy and lacking a lot of experience and knowledge, I'm hoping u guys can lend me some of yours    I just hope that I havn't pointed myself in the wrong direction. thanks.

[RD]

welcome to the site.

first thing i see as being a problem is your pushrod length.  unless you had custom pushrods made, those pushrods will cause your valves to stay slightly open which will bring combustion issues, valve and valve guide/seat premature wear and tear. 

I have not used a K54 engle cam, chryco or firefighter may chime in on that.

the smaller chamber of your head, plus the copper gasket will raise your compression to maybe 9 to 9.25 to 1 range, this is totally a guess.  I do not see it much higher than that.

has the intake side of the heads been milled also?

So, in closing:

1) get custom built pushrods before you run that vehicle
2) have a reputable machine shop check out your heads to see if the intake port side has been machined to the acceptable geometric angle so your intake will fit.

[Chryco Psycho]

I agree , the pushrod length will be off , also unlees the heads or intake were milled down the intake will not fit
I really need a head cc to easily figure out the compression ratio but approx you will gain 1.2 compression with .080 milled off
the next ? I have is that my machinist has said that .050 i sthe limit to miill off a stock head , are you SURE they werre milled .080?

[charger440]

I'll double check everything, i didn't personally get it done myself so the best thing to do is to take it to a machine shop to get it checked out. However the guy said the intake manifold will fit fine so im assuming he got the intake side milled aswell , but he also said the pushrod length shouldn't be a problem... although i know the same amount should be off them

btw, thanks for the welcome, ive been a 'viewer' of this forum for about the past 2 years, gaining knowledge lol

[73 Charger 440]

Wow... Someone stole my avatar icon from years ago. Charger440 please remove it as it is work created by me (I have files and can prove it), some may remember the icon back from the old site.

[firefighter3931]

I'll agree with the others, pushrod length will be an issue. Also the rocker arm geometry will be changed with that much milled off the deck surface of the head. You can use rocker shaft shims to partially correct the geometry issue but you're probably looking at a set of shorter pushrods as well.


Ron

[charger440]

Ok sorry 73 Charger 440, i got that a while back.. i didn't think it was from this site or from you but i guess it must of been lol. Thanks for the info firefighter, my information from you guys and the guy i got these heads from seem to be contradicting each other, so I'm going to take them to a machine shop hopefully early this week and see what they can tell me. Why would the guy say i won't have any push rod or rocker arm issues, he's not a dumb guy,  maybe I'm the dumb one lol 

[deputycrawford]

I had a guy tell me that he had his 906's milled .090 for his drag racing. He said that is the absolute max you want to shave them. As long as the intake side was re angled then you should be ok.

[73 Charger 440]

Ok sorry 73 Charger 440, i got that a while back.. i didn't think it was from this site or from you but i guess it must of been lol. Thanks for the info firefighter, my information from you guys and the guy i got these heads from seem to be contradicting each other, so I'm going to take them to a machine shop hopefully early this week and see what they can tell me. Why would the guy say i won't have any push rod or rocker arm issues, he's not a dumb guy,  maybe I'm the dumb one lol 

Hey, no problem at all... Thanks for removing it, I understand how it is to find stuff on the internet (Im still wondering where you found it from  ), I would just rather have people ask for permission.

[SeattleCharger]

Wow... Someone stole my avatar icon from years ago. Charger440 please remove it as it is work created by me (I have files and can prove it), some may remember the icon back from the old site.

               

                                Remember this signiture pic someone had on here?   heh,

[73 Charger 440]

Wow... Someone stole my avatar icon from years ago. Charger440 please remove it as it is work created by me (I have files and can prove it), some may remember the icon back from the old site.

               

                                Remember this signiture pic someone had on here?   heh,

Great morning laugh 

[Challenger340]

Do you have the "milled" 906 heads off right now ? 

You can measure the depth of the open quench side of the chambers and get a "ball park" as to the amount of milling they've incurred. They won't all be the same, but an average depth from all 4 chambers is "close". Stock quench side(open area) depths should be in the .100" range.

If in fact they've been milled .080", the open area of the chamber will only be around .020" or so, VERY shallow. If they are, DITTO the pushrod and geometry thing from  firefighter3931's post.

[deputycrawford]

I had mine milled .050 and had to order custom length stuff. Just a couple days turn around time and not much money either.

[charger440]

Do you have the "milled" 906 heads off right now ? 

You can measure the depth of the open quench side of the chambers and get a "ball park" as to the amount of milling they've incurred. They won't all be the same, but an average depth from all 4 chambers is "close". Stock quench side(open area) depths should be in the .100" range.

If in fact they've been milled .080", the open area of the chamber will only be around .020" or so, VERY shallow. If they are, DITTO the pushrod and geometry thing from  firefighter3931's post.

I do have the heads off, i haven't had time to take them to a machine shop or anything, so i will measure them when i get the opportunity.. since they aren't where i live right now. Thanks for the the info on how to get a ball park measurement, very much appreciated. And thanks to all for the replies, they're very helpful.

[Challenger340]

Hope it helps you out !

[charger440]

Well, i measured the open quench side of the chambers, i got about .075... odd number lol.. and I'm going to use the .020 steel shim gaskets, will i still have pushrod and valvetrain issues?

[Challenger340]

You might or might not.
Sorry to be "vague", but at .075" for the average, as to the open side depth, I'm guessing the heads have undergone a milling of approx. .030". Probably be fine with a composition type head gasket, but I'm not sure with the steel shim.

The Intake may still fit, might require a bolt hole "oblong" but not terrible.

Just my opinion, but I think your best to do a mock-up, and measure the actual amount of Lifter preload you have. Valvetrain Geometry can be checked at the same time.
Compcams website used to have a far better description of proper geometry than I can give here, might be worth a try.

Hope this helps, good luck with the project.