billwillard Posted November 28, 2007 Report Posted November 28, 2007 I took my head to the machine shop to have it shaved and hair cut. They told me that it has already had a shave job but had no way of telling how much as they didn't know what stock mearsurement was. They do not do hair cuts. My question is does any one know what a stock head that has never been cut would measure Through the bolt holes? Engine is 1956 PLYMOUTH 230 THANKS Bill Quote
Plymouthy Adams Posted November 28, 2007 Report Posted November 28, 2007 Bill.......what year head you talking about??? No sure how they made the compression changes over the years...was it in the casting or in the cut of the head from the factory...someone here may know but I am thinking apples to apples may be the best gauge here...do you have a casting number available? Quote
Don Coatney Posted November 28, 2007 Report Posted November 28, 2007 Bill; James Douglas found a NOS long block head and sent me the measurements as pictured (1.930" through a head bolt hole). Yours may be different as you have a short 23" engine. Quote
Plymouthy Adams Posted November 28, 2007 Report Posted November 28, 2007 230 1954 1554674-5 1.938 218 1948 1120803-7 1.958 230 1958 1676337-2 1.905 218 1941 1120803-3 1.990 230 1947 1120803-4 1.938 these were taken at the second bolt to the rear on the drivers side just behind the thermostat housing..depth gauge at top of gasket and flat of bolt boss... given that measureing like this is not absolute and will ball park only...take the 41-218 and the 47-218 the difference in compression of .3 between there stated spplication could very well be the difference in the cut of the head which is approx. .030 rounded to nearest .010 as is common when milling. Then the 230 in 47 and 54 being approximately the same... But in 1958 the increase in compression ratio is greater yet and my book does not quite that high but again if rounded to nearest .010 you will again see a difference of approx .030. I am almost to the point of thinking as rule of thumb that.030 may be about .3 CR.....but then again this is pure speculation on 5 heads without totally history known...maybe you have other thoughts here... 1 Quote
billwillard Posted November 29, 2007 Author Report Posted November 29, 2007 THANKS Don and Tim. I told him to cut it to about 1.890 which I think should be about .40 off stock. Thanks agin Bill Quote
woodscavenger Posted November 29, 2007 Report Posted November 29, 2007 Looks like that Spitfire head was spit on and then put in the fire!!! Can that thing be resurrected? Quote
Plymouthy Adams Posted November 29, 2007 Report Posted November 29, 2007 I think you will find a picture of that in the archives from Don...Ihave seen the head in question after the clean and paint... Quote
Don Coatney Posted November 29, 2007 Report Posted November 29, 2007 Looks like that Spitfire head was spit on and then put in the fire!!! Can that thing be resurrected? It is now ready to install. Quote
Guest rockabillybassman Posted November 29, 2007 Report Posted November 29, 2007 The best way is to install it with clay on the valve heads, torque it down, then take it off and measure how much clay you've got. The machinist will be able to work out how much to remove. Anything else is speculation. Quote
grey beard Posted November 29, 2007 Report Posted November 29, 2007 I used solder on top of my valve heads - tightened it down with a new gasket and several bolts. My B1B head clearance allowed me to take off 100 thou and still have nearly that much clearance on top of both valves. Probably could have taken much more off. Guess I'd say these heads were downright "roomy" when it comes to haircuts. JMHO Quote
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