Head Shaving

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Mar 8, 2001 | 09:11 PM

bufordt

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Head Shaving

I have a 77 Ford 400 bored 60 over with a Comp Cams 270H Magnum Series Cam with a duration of .224 and lift .519 intake and .519 exhaust. My question is what be the maxium amount i can shave my heads and not worry about piston to valve clearance problems. I dont want to go the maxium but want to get a little higher compression ratio. Thanx

Mar 8, 2001 | 10:38 PM

DBF

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Head Shaving

The only way to answer your question and be exact, is to tell you to clay a cylinder. I assume you've pulled the heads because you are going to raise the CR, so, either with an old head gasket or figure it in later, spray a piston and combustion chamber lightly with WD-40, lay a couple of rolled up strips of clay across the valve cut outs on the piston for each valve and then with four bolts or so, tighten the head up by hand. Turn the engine over by hand once, two revolutions, and remove the head. You can now measure the thickness of the clay to find out how much clearence you have and from there you usually want about .080 clearence for the intakes and .100 for the exhaust, but...you now have to figure the compression ratio so you don't mill .080 of the head and end up with 12.1 CR.

With the amount of clearence varified by the clay, the Engine Shop will be able to compute the rest for you.

Jim

Mar 9, 2001 | 06:57 PM

fozzy

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Head Shaving

I HAVE A FRESHLY REBUILT 400 BORED .040", I had the heads shaved about.030" , the machinist said anymore than that wouldnt be wise because of your intake bolts not lining up correctly.he was somewhat right. the intake bolts were a little tight, (I thought I was cross threading at first)anyway here is a part number and phone number for some 10:1 pistons for the 400, I wish I had found them three months ago when I rebuilt

BADGER PISTONS PART NUMBER :#400-100F
PHONE NUMBER : 1-626-869-0270
THE COST IS $144 FOR THE PISTONS (CAST) AND PINS ALREADY PRESSED IN.... THEY HAVE THEM IN STD.,.010",.030",.040",.060" BORED SIZES

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77'FORD F150 XLT 400

Mar 9, 2001 | 07:01 PM

fozzy

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From: New England

Head Shaving

oops

I almost forgot your original concern, P:V clearance...
as long as you stay away from a 300-310 degree cam, and set timing to no more than 14 degrees initial, you will have no problems
ps you may wanna get some good valve springs if you havent already
, I used a set of edelbrock sure seat springs from summit for less than $50...
GOOD LUCK
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77'FORD F150 XLT 400

Mar 10, 2001 | 10:42 AM

dinosaurfan

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From: SW Michigan

Head Shaving

Buford- don't know about your clearance, but if you want to take 060 off the heads, that is no problem. It does alter the way your intake fits, however. The right way to do it is to cut the intake face of the head the same amount as you did the deck. Never mill an intake manifold. You might also want to use RTV instead of end seals when you assemble. DF

Mar 13, 2001 | 09:04 AM

buzzard

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Head Shaving

Mar 13, 2001 | 07:56 PM

bufordt

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Head Shaving

[font size="1" color="#FF0000"]LAST EDITED ON 13-Mar-01 AT 09:04 PM (EST)[/font][p] Thanks for the info guys. When i rebuilt the engine, i used Badger Pistons but didnt realize until now the made a higher than stock compression ratio. Live and Learn i guess. So other than disassemble the engine to put in new pistons i think ill just pop the heads off and take a little bit off. For what no more than what ive done to this engine its by far the strongest ive ever built im really impressed. Incase anybody was wondering about my name thats not Buford T. Justice it what my liscense plates say which means Built Ford Tough.