DonaldSmith Posted November 30, 2017 Report Share Posted November 30, 2017 Dpollo said that the Spitfire head would lower the compression ratio, and stated some bore and stroke dimensions. I guess I don't understand. Don't the pistons rise to be level with the top of the block, regardless of bore and stroke? I can see different heads having different combustion chamber volumes. I could see a problem with a head cast for a small bore, but used with a large bore. The pistons might kiss the head at the edges of the combustion chambers. Quote Link to comment Share on other sites More sharing options...
Brad47 Posted November 30, 2017 Author Report Share Posted November 30, 2017 Thank you I’ll try Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted November 30, 2017 Report Share Posted November 30, 2017 17 minutes ago, DonaldSmith said: Dpollo said that the Spitfire head would lower the compression ratio, and stated some bore and stroke dimensions. I guess I don't understand. Don't the pistons rise to be level with the top of the block, regardless of bore and stroke? I can see different heads having different combustion chamber volumes. I could see a problem with a head cast for a small bore, but used with a large bore. The pistons might kiss the head at the edges of the combustion chambers. Well what does bore and stroke do???? In a 250 or a 265 the cylinder volume is larger, correct? Now lets use the 250 4 1/2 inch stroke 3 7/16 bore. A 218 has a 4 1/8 stroke and 3 3/8 bore. So now if you placed the smaller chamber 218 head on a 250 it increases the compresssion accordingly. Place the larger 250 on a 218 and theoretically you lower compression accordingly. My illustration is a bit vague but it gets to the point. Perhaps Dpollo can elaborate on this in more detail.... Quote Link to comment Share on other sites More sharing options...
Brad47 Posted November 30, 2017 Author Report Share Posted November 30, 2017 It would be nice if it could work but it’s a little out side my realm of expertise. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted November 30, 2017 Report Share Posted November 30, 2017 I used a dial indicator to measure valve lift with my reground cam to insure I had ample valve to head clearance with the shaved head I installed. 1 Quote Link to comment Share on other sites More sharing options...
greg g Posted November 30, 2017 Report Share Posted November 30, 2017 Don, what was your total lift on the regrind? I believe stock was on the order of .0375 to .0395, so trying to find out how much higher the regrind was over stack. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted November 30, 2017 Report Share Posted November 30, 2017 33 minutes ago, greg g said: Don, what was your total lift on the regrind? I believe stock was on the order of .0375 to .0395, so trying to find out how much higher the regrind was over stack. Advertised at .410" lift minus the .015" lash for an actual of .395". I do not know the factory lift. Quote Link to comment Share on other sites More sharing options...
greg g Posted November 30, 2017 Report Share Posted November 30, 2017 I was told .375 by George. .020 doesn't seem like a lot of difference. Even at the full .410 it doesn't sound like it would make a lot of difference. Was there a big change in duration? Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted November 30, 2017 Report Share Posted November 30, 2017 13 minutes ago, Don Coatney said: Advertised at .410" lift minus the .015" lash for an actual of .395". I do not know the factory lift. Its a .395 lift and a 242 duration a common mild cam. Stock is .375 lift. That cam should spin up to 4500 rpm though. There certainly are more agressive but as they rise so does being less street tame. Not a real hiperf cam grind but a little more pop than stock.. Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted November 30, 2017 Report Share Posted November 30, 2017 2 minutes ago, greg g said: I was told .375 by George. .020 doesn't seem like a lot of difference. Even at the full .410 it doesn't sound like it would make a lot of difference. Was there a big change in duration? .410 is a big difference Greg specing from .375. Now .435 gets wild... Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted November 30, 2017 Report Share Posted November 30, 2017 2 hours ago, Don Coatney said: I used a dial indicator to measure valve lift with my reground cam to insure I had ample valve to head clearance with the shaved head I installed. This is a rough guide line and does not specifically include a Canadian 218. Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted December 1, 2017 Report Share Posted December 1, 2017 Okay fooling around in the shop for a few minutes this afternoon. I actually ran my ATV and snow blade down the driveway a few times, had a about an inch of snow....LOL So I pulled the head off my Industrial 265 engine, here are some pics, thew chambers are huge and quite deep, I do think this head might have been cleaned up in the last rebuild. This engine is not bad, and if it did not have a tiny bit of cyl ridge and a rust spot on cyl 6 I would fire it up and possibly use it as is. This head will not be getting used, I am looking specifically for a late 1950s big truck 250 or 265 head if possible. This engine is supposed to have 7:1 compression ratio, as per 1960s spec for Massey combines, now if this is true, not sure why it can't be milled to accomplish 8 or even 8.5:1 compression, but have been advised its not a good head to use and milling will not improve it. This head on a 218 or a 228 would no doubt drop the compression drastically. If I milled it, it most likely could stand to .100 Quote Link to comment Share on other sites More sharing options...
Brent B3B Posted August 7, 2019 Report Share Posted August 7, 2019 Recycling the thread title.... ? can someone tell me why three of my head bolts are threaded inside the head of the bolts? I am guessing this is a transplant motor in a truck I have......just curious Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted August 7, 2019 Report Share Posted August 7, 2019 (edited) They are threaded to mount engine parts and ground cables to the cylinder head area of the engines in both cars and trucks. The tread size is 3/8" X 24 TPI On some of the trucks.... 1-1/2 ton on up two are used to mount the top bracket of the oil filter housing to the drivers rear side of the head. Chrysler straight eights use them to mount the air cleaner bracket on 1946-48 Cars. The head is a 1946-54 Chrysler car head... could be a valuable 265 engine? Edited August 7, 2019 by Dodgeb4ya 1 Quote Link to comment Share on other sites More sharing options...
40desoto Posted August 7, 2019 Report Share Posted August 7, 2019 1 hour ago, Brent B3B said: Recycling the thread title.... ? can someone tell me why three of my head bolts are threaded inside the head of the bolts? I am guessing this is a transplant motor in a truck I have......just curious On my 1954 265 engine those threaded bolts are to mount the throttle linkage assembly on top Quote Link to comment Share on other sites More sharing options...
greg g Posted August 7, 2019 Report Share Posted August 7, 2019 Most stock heads measure 2 inches thick at the head bolt flat to the bottom edge of the head where it meets the block. A micrometer measurement should indicate whether the head has been milled earlier in it's life. When I first my 56 230 engine, I have .040 taken from the head and .010 from the block. My machinest calculated compression went from 7 to 1 to 8.5 to1. A healthy increase. So measure your head and any you might think of buying to establish if they have been messed with. My opinion is the increase in CR really wakes up these engines some one has suggested that .090 is the limit without needing to mess with valve clearence unless you have a highlift cam installed. 1 Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted August 7, 2019 Report Share Posted August 7, 2019 My Spitfire head measured 1.930". I do not know if it had ever been shaved. Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted August 7, 2019 Report Share Posted August 7, 2019 (edited) 10 hours ago, Brent B3B said: Recycling the thread title.... ? can someone tell me why three of my head bolts are threaded inside the head of the bolts? I am guessing this is a transplant motor in a truck I have......just curious On my 1941 Spitfire, threaded bolts are for throttle bracket, Vacuum tube to carb, clips, and air cleaner bracket Edited August 7, 2019 by chrysler1941 Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted August 7, 2019 Report Share Posted August 7, 2019 (edited) this has been answered twice now......they are for mounting various engine control brackets and often also found up front in the vicinity of the thermostat housing as a battery ground point. In all seriousness, I would look at replacing that heavily corroded one pictured... Edited August 7, 2019 by Plymouthy Adams 1 Quote Link to comment Share on other sites More sharing options...
Matt Wilson Posted August 8, 2019 Report Share Posted August 8, 2019 I'll answer it a third time. On my '49 Power Wagon, these bolts were used for attaching the horn. 1 Quote Link to comment Share on other sites More sharing options...
Brent B3B Posted August 8, 2019 Report Share Posted August 8, 2019 13 hours ago, Don Coatney said: My Spitfire head measured 1.930". I do not know if it had ever been shaved. I’m right with you Don, measured 1.925” sadly though I think only the head was changed for “ the cool factor”.... Thinking i only have a 236 in this truck. Thanks everyone for the info. Quote Link to comment Share on other sites More sharing options...
greg g Posted August 8, 2019 Report Share Posted August 8, 2019 I used them to facilitate the building of my dual carb throttle linkage, and for fastening my battery ground strap not yet attached in this pic but you can see the threaded head near the thermostat opening. 1 Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted August 8, 2019 Report Share Posted August 8, 2019 1 minute ago, greg g said: I used them to facilitate the building of my dual carb throttle linkage, and for fastening my battery ground strap not yet attached in this pic but you can see the threaded head near the thermostat opening. My opinion threads are too few for serious ground connection. Quote Link to comment Share on other sites More sharing options...
greg g Posted August 8, 2019 Report Share Posted August 8, 2019 Been working fine for over45000 miles. Quote Link to comment Share on other sites More sharing options...
kencombs Posted August 8, 2019 Report Share Posted August 8, 2019 2 hours ago, chrysler1941 said: My opinion threads are too few for serious ground connection. But, the real connection is between the flat cable end/bolt/washer/bolt sandwich. Not just the threads. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.