Hi,

Ive been told shaving the head is good for increase of compression.
So I have a few questions to ask of you geniuses.

Is it worth it?
How much have you paid or do you think it'll cost (AUD or USD etc), in total.

I am guessing you have to adjust valves and cam (think the cam timing would be off a little?)

Or should I just get high compression pistons, or both.

And is there anything else that I should get done at the same time just to make sure the head stays in good condition and stuff.

Thanks heaps!

Shaving the head is well worth the money. It can get expensive though. If you are pulling the head you may as well get a valve job while it's at the machine shop. If you are having a valve job done you should probably have the guides rebushed, then there is dissasembly and reassembly, gasket set, hot tanking...
I spent almost $500 all together when I had a head done but it was well worth it for the increase in power and driveability. IIRC the actual shaving of 0.100" was $120. It took 2 passes at $60 a pass to take that much off. they told me their machine could do up to 0.065" a pass.

I'm not sure you can even get high compression pistons for a slant(I never looked into it) shaving a head is a much easier way to gain compression, since you don't have to pull the engine out and totally dissasemble it.

I didn't need to do anything to the cam, pullin the head off of a slant dosen't involve messing with the cam. I didnt even get shorter pushrods, there was plenty of play in the rocker adjusters.

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Good question Brussell, no easy answer though:

Raising compression will increase engine output, however, an engine is a bit like a base ball team. You can’t improve the team much by replacing your second baseman with an all star quality player… Particularly if the team a stumbling collection error generating over the hill bums.

Think of your slant as a team. What must be done to get it playing up to minimum factory standards? Is your outfield capable, and not out there on crutches trying to keep up?

In other words, what condition is lower-end of your engine currently in?
What is the compression in each cylinder.
How is the oil pressure at idle & above?
Is the distributor tight with no slop in the barings?
Timing chain lose or in good shape.
Rear main leaking?

If all these areas of the lower-end are in reasonable good tune, than head work can be done, and produce performance gains.

The infield is where fine tuning can make a big difference in how the game is played.
Shaving will raise compression, but how much is needed?
Shave a little off, keep your current shortstop, the cam, and 87 octane fuel, as well as stock manifolds.

But, while you have the head off, why not increase valve size with perhaps [url=http://www.enginepartsnetwork.com/valves.htm] these[/url] from [url=http://engnbldr.com/] Engnbldr [/url], perform a three angle valve grind, and clean up the ports & bowls for smother air flow to & from the combustion chamber.

Now that your head is flowing better, time to consider up grading to a 2V or 4V carburetor, intake & exhaust manifolds, and exhaust system to get more air to the combustion chamber, and get it out of the combustion chamber. To make all those improvements work, you will need a cam-up grade. Than a distributor re-curve, ignition up grade, if an automatic transmission car, perhaps a higher stall torque converter will be needed… And, on it goes; Mission Creep, it never ends, always restlessly stalking your wallet & time.

A few years ago I gasket matched, mildly ported the head & intake manifold my self; a tedious time consuming job requiring 100 bucks worth of tools, a steady hand and not grinding through to the water jacket which turns a good head into scrap iron.

Machine shop shaved enough off the head for 9:1 compression ratio (this was pre calculated) so I can run 87 octane fuel, installed over sized valves & hardened seats with a three angle grind, and dressed the manifold meeting surface, for around 350 bucks or a little less. I can’t remember exactly.

My car all ready had a hot cam, Clifford headers & intake, and a little Holley 390 cfm 4V carburetor that saved me a bundle. The head work made a big difference that I could feel immediately on the first drive.

This change in the team worked for me, because the lower-end was in good repair; hot cam was in place, and aftermarket intake, headers & carburetor were all ready hanging off the engine waiting to be used to their full potential.

If your engine is stock, relatively in good shape, a “Super Sixâ€￾ up-grade is a very cost effective change not requiring costly machine shop work, and head removal that you can easily perform in your garage.

Genius
two

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Sorry guys I should've said, I'm such an idiot.

Already got a whole brand new elec ignition setup with bigger coile and new dizzy etc. + will have the long runner intake + 350 holley, + heads been ported and polished + extractors.

Was thinking of raising the comp to 10:1. and then getting a new cam to suit.

Thanks so much you've both been a great help.

In the coming weeks I'm going to take the car to my local engine shop. The car apparently had a recon before I bought it. However I will get all that head work checked and I think I know a mopar site that'll have the pistons.

www.pentastarparts.com.au

thanks guys!

I had mine shaved a while back I took the bare head to them clean, so I did not have to pay for extra labour. To shave 0.100 it cost me $90 US. Shaving 0.100 brought my compression to 9.25:1.


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