milled heads

[73Valiant]

Can anyone tell me if I'll need custom pushrods with milled 360 heads?
Here's the engine info:
'78 318 stock flat top pistons
'80 360 heads ported----- not milled yet!
CompCams XE268H
.477 intake lift .480 exhaust
Aluminum single plane intake
Flowtech headers
2.54 gears (3.55s on their way in)
standard transmission
Now I'm wondering if I had these heads milled .050 would I need new pushrods or will the stock ones be fine. Not racing or anything so revs wont be too high very often. OR if the heads were milled less would the stock pushrods work?

I also have some '98 magnum heads but dont really have the funds to get the aftermarket pushrods and valve springs and retainers, plus making the intake fit or buying a new one! even if i did the valve lift would be around .512 with the 1.6 ratio rockers which I'm guessing might hit the pistons?

ANY help greatly appreciated!!! especially about the milled head question

I DO have future plans for a roller cam/roller rocker 360 but that'll definetaly have to wait

 

[BJR Racing]

With that cam you will have plenty of valve to piston clearence even with .050 milled off the heads.
You can only mill .030 safely with stock pushrods as the lifter only has about .060 travel total and the pushrods should be in the middle of travel or close. So my suggestion would be to run a fully adjustable velvetrain and eleviate this problem. Also keep in mind that when you mill this much off the deck surface of the heads that you will also have to mill .012 off the intake face of the head so to keep the intake geometery right for every .010 off the deck of the head.


BJR Racing

 

[73Valiant]

Okay so if i wanted to do this the cheapest way possible then I should just get .030 milled off the heads since a fully adjustable valvetrain won't be affordable unless it's under $100 ha ha ha 8-)
Couldn't I just get shorter pushrods?

 

[BJR Racing]

I'm not sure if they still make the adjustable pushrods or not, by this is a 30 yr. old thing?....................not sure? too long for me! and I'm old to hear Mrmopartech say it!

BJR Racing

 

[Mrmopartech]

MR.Valiant,I can understand the fact of saving money and trying to do it on the cheap side,but their is a piont where you stop and have to say,enough is enough.We are not asking to go out and buy the 4000-6000$ nascar valve train gear hear,we are asking you to spend a couple of hundred dollars on the factory adjustable rockers or a deal on ebay or from a member to have the valve train adjustable so you can run and enjoy it properly.Deals of 1.5 alley rockers are on jegs,summit,and ebay all the time,and memebers on different sites as well.So lets ask our selfs this,do I go cheap and risk a motor failure and any money I put into it,or spend correct money and have the enjoyment of having the motor run right and stay together and have miles of pleasure.A set of iron adjustable rockers is CHEAP inssurance to valve train parts staying where its meant to stay.Running a set of non adustable rockers is just asking for trouble with your combo.If you take your girl freind out for a special night and get all dressed up looking your best,and you look hot,do you wear your old smelly running shoes with the holes in them to the dinner club,No,you wear the proper shoes and socks to fit the part,same goes for the motor,if you are cheap,plan on at least 2-3 complete rebuilds in 1-2 summers,and no dinners out,Mrmopartech

 

[BJR Racing]

Geeeeeeeeesssss,Kind of personal aren't we..........but then I know wher it comes from. ..........................LOL

 

[dusterdon]

Low buck way is to shim the freakin rocker shafts. Also consider how thick of a head gasket you're gonna be using. Factory was around .020 and a Felpro type is around .040. So don't cut the heads .030 then use the thick gasket to end up with only a .010 reduction.

don

 

[73Valiant]

that's a pretty funny analogy Mrmopartech!
I'm just trying to get it back on the road as I've turned it from a simple timing chain swap into this: NEW cam,lifters, valvesprings, cylinder head swap, header install with duels
PLUS I'm attempting to install a 5 speed out a dakota and in the process have had to swap out the brake booster in favor of a manual master cylinder brake set up
PLUS I went to change my brake hose and the line snaped off
PLUS I've had to cut a massive hole in my floor/tunnel to accomodate the tall NV2500
PLUS another hole for the clutch/brake pedal asssembly with the clutch master cylinder
THEN install the 8 1/4 rear axle!!!
Kind of a uh... MAJOR PROJECT!!!!!
This is all being done to a 78 Volare so if there are any die hard fans out there thinking that I'm ruining a collector car don't worry about it :-D

So I'm at a point where I might just bolt on my 360 heads 70ccs mildly ported completely rebuilt and just get it back together... you might think it would make it even less of a performer but it's a HUGE improvement compared to what the 318 was running...
Firstly the stock 318 heads are 70ccs, SOOO carboned up that some spots were about an 1/8" thick, the cam had some pretty nasty grooves in it, the lifters were cupped, the valve seals were all in the oil pan, timing chain had WAY too much slack, most of the spark plug tips couldnt be seen due to all the carbon build up on them, had a worn out 2brl on it, and single exhaust measuring 2" outlet
oddly enough I still beat a 5.0L mustang??? :shock:

 

[moper]

.050 is no big deal, but correct hyd lifter preload and rocker geometry need to be kept in spec. When the heads get new valves, or a valve job, these can also be thrown out of whack. You know you're milling .050 off, so you'll need to mill at least .050 off the intkae..Not the intkae surface of the heads..the intake itself. Reason? Your valve cover gasket head flange, is what you're milling off, to make the manifold fit. Any more than .030 off this flange, is asking for leak problems later. So now you need to have a "fits one cyl head combo only" intake made...It's around $50 to have that done around here. So, now the intake fits, and the heads are bolted on (leave the intake off)..Try tightening down on the rocker shaft with the pushrods in place they ones that are on the cam ramps (valves opened) wont go all the way down. You've bottomed out the lifters....you can see this in the way the plunger is way down int he lifter body..using a set of wire feler gages, you can measure the amount of space between the plunger and the retainign clip inside the lifter body. Safe bet, you'll need to shorten the pushrods by at least .050". Comp Cams offers these, as do others, that are designed for factry style staped rocker arms. They cost about $125. The alternative, is as mentionned, adjustable rockers, and cheaper new pushrods with cups for the rockers. Together, $70+$199 (add $199 aluminum rockers arent worth $100...not worth bothering with IMO) The rock bottom cheapest way is to use shims under the rocker shafts. But, dotn think that .050" worth of shims is perfect. They might be, but the only way to get it "right" is to measure the preload. Aim for .030-.040" per lifter. Shims will go $30 a pack or so, and you'll need 2 boxes I think. So, at minimum, you have $60 in shims, and $50 in extra milling to make it all fit. Also, it's the grunge way out, dont rely on it revving to 6500 on a regular basis...lol.