Shaving a 218 head vs. a standard 230 head?

[Thomba48]

I am not planning a lot in terms of power boosts for my 1949 Plymouth. Shaving the head (or something else) shall be the first step. And then end of next year a dual carb set-up will be on the agenda.

In regard to the "head shaving" matter: What brings the best performance boost shaving the head of an actual 218 engine or exchanging the head with a 230 head (I believe they should fit my engine).

 

thanks for your insights

Edited December 3, 2017 by Thomba48

[Don Coatney]

This reference chart might or might not help.

[Plymouthy Adams]

the problem with just shaving a head is knowing if it has been done in the past...let us just rule out the fact that the PO as not into performance for such action but as we all know the changing of hands over the years, the upkeep of maintaining a running engine....it could well have been shaved a couple time already at head gasket jobs may dictate.  There is not a stock chart for thickness for the remaining metal.  To accurately shave the head one really needs to do a head chamber CC measurement for a starting reference.  Assuming it is stock and in fact has been cut in the past leaves you guessing from this point forward....finding the current ratio and using the chart above can be a bit safer approach.

Edited December 3, 2017 by Plymouthy Adams

[Ajgkirkwood]

There was a post about the heads being messed with where stock is 2 inch thick. Seems i can have .1" removed in mine. Wow. If that mich is removed. Do you face/remove some off the face of the valves?

[Plymouthy Adams]

if you mess with the face of the valves you will be removing precious metal needed to keep the valve cool enough top prevent burning.....check your book...there is a minimum distance above the seating surface to meet this criteria...while not in the chart for dimension on the valve, it is well defined in the white pages when you address resurfacing valves...

[dpollo]

just remember that the 230 head has a larger chamber than the 217.    So putting a 230 head on a 217 will lower compression.  

[P15-D24]

18 minutes ago, dpollo said:

just remember that the 230 head has a larger chamber than the 217.    So putting a 230 head on a 217 will lower compression.  

Don't believe that is accurate. Hollander's shows them as all the same, direct swap. Think the only different is the stroke. 

[55 Fargo]

1 hour ago, P15-D24 said:

Don't believe that is accurate. Hollander's shows them as all the same, direct swap. Think the only different is the stroke. 

Not exactly.

Is the Hollanders referring to a fit which of course it would for internal later types as well as the earlier external type differences. Internal with internal and external with external.

There were a number if different heads created too even for just a 230 specific engine. 

A 1 size fits all for heads is not the case.

In fact we have been down this road on another thread that is currently locked.

I would add the longer stroke engine might have larger combustion chambers to accomplish a specific compression ratio.

From.an engineering stand point a longer stroke would thrust more volume into the CC, raising pressure, thus a slightly largerCC volume would regulate the compression ratio.

I.have a 265 industrial engine with a 4 3/4 stroke and a specified 7:1 comp ratio.

This head would lower the comp ratio on  say a 228 engine with its 4 1/4 stroke. The combustion chambers are huge.

At any rate it would be nice to see pics of an early 230 head as well ad the later 230 head compared to the 218 head.

 

Edited December 3, 2017 by 55 Fargo Spitfire

[greg g]

From having a head off a 218 as well as a 230 I can attest to the following observation; the pistons on the 218 at tdc are about 3/32nds of an inch below the surface of the top of the cylinder, the pistons of a 230 at tdc are nearly flush with the top of the cylinder.  Throw in the thickness of the head gasket and this suggests that if the heads had the same cc combustion chamber the 218 would be smaller (less metal removed from the head) to make up for the distance between the top of the lower piston and the underside of the head. This would suggest that this 218 head when placed on a 230 would lead to an increased cr due to the smaller size of the chamber with the smaller piston to deck position.

The highest HP 218 was early 54 showing 110 HP with 7.25 cr.  An earlier 218 with 7/1 made 97 HP, while a year later it made 100 HP with 7.1 to 1

So while Hollanders suggests the heads interchange mechanically it makes no mention on what the swap does regarding cr or HP.  So unless and until some one cc's certifiable stock heads, looks like its a crap shoot.

[55 Fargo]

Greg i find it interesting that in 1954 the 217 has a 110 hp rating with only a .25 change in compression ratio.

That is 13 more hp over a  1950 engine.

So theoretically raising the same engine to 8:1 would result in a 52 hp difference? To a 149 hp 217 engine.

Of course it wouldnt but what else about the head or induction changed for the 1954 217 engine?

Edited December 3, 2017 by 55 Fargo Spitfire

[Thomba48]

May I rephrase my original question :-)

Obviously compression is an important measurement for improving the engine performance. All I have read is completely logical. Especially the part referring to the fact that simply shaving off a head without having tested anything else being a bad thing to do :-)

Now I might be able to acquire an NOS head originally ment to be used for a a Dodge M37. So technically this should be a 230 head. Am I right?
Would that exchange be a. possible from a technical perspective b. beneficial from a compression perspective? Also, being NOS nothing has been done with it before. Would it therefore be additionally "benefecial" to shave that particular head for further improvements? thanks

[55 Fargo]

13 minutes ago, Thomba48 said:

May I rephrase my original question :-)

Obviously compression is an important measurement for improving the engine performance. All I have read is completely logical. Especially the part referring to the fact that simply shaving off a head without having tested anything else being a bad thing to do :-)

Now I might be able to acquire an NOS head originally ment to be used for a a Dodge M37. So technically this should be a 230 head. Am I right?
Would that exchange be a. possible from a technical perspective b. beneficial from a compression perspective? Also, being NOS nothing has been done with it before. Would it therefore be additionally "benefecial" to shave that particular head for further improvements? thanks

Canadian Built Powerwagons came with 250s and possibly 237s, both 25 inch engines. Just a FYI

Edited December 3, 2017 by 55 Fargo Spitfire

[Thomba48]

1 minute ago, 55 Fargo Spitfire said:

Canadian Built Powerwagons came with 250s and possibly 237s, bot 25 inch engines. Just a FYI

thanks

[Thomba48]

2 minutes ago, Thomba48 said:

thanks

This particular head is a 218/ 230 one not the 250 Canadian one

[Plymouthy Adams]

2 hours ago, greg g said:

 

The highest HP 218 was early 54 showing 110 HP with 7.25 cr.  An earlier 218 with 7/1 made 97 HP, while a year later it made 100 HP with 7.1 to 1

 

The 54 Plymouth 218 was rated for 100 ponies and the 230 engine Plymouth introduced later as signified by the diamond before the number was the engine rated at 110 ponies.

[dpollo]

6 hours ago, P15-D24 said:

Don't believe that is accurate. Hollander's shows them as all the same, direct swap. Think the only different is the stroke. 

Let us suppose we have two engines side by side, both manufactured the same year.  One is a 218, the other a 230,  Both have 3 1/4 bores    The 218 has a 4 3/8 stroke.  The 230 has a 4 5/8 stroke.  The pistons on each are level with the deck at TDC.   Each left the factory with a 7 to 1 compression ratio.

Given the larger volume of the 230's cylinder  how could it have the same compression ratio as the 218 if the chamber size was the same ?

Hollanders is correct only in that the heads are a bolt for bolt swap.      

A 53-4 parts book shows part number  1327008 for a P25  (218)   and 1326310 for a D46 (230)     and that's my client's case, your honour and he's sticking with it.

[greg g]

But as I observed, the 218 pistons are below the level of the deck at TDC so a given head when swapped to a 218 would have a lower cr as the squish are is larger based on the depth of the piston at TDC.

 

 

[Plymouthy Adams]

27 minutes ago, dpollo said:

Let us suppose we have two engines side by side, both manufactured the same year.  One is a 218, the other a 230,  Both have 3 1/4 bores    The 218 has a 4 3/8 stroke.  The 230 has a 4 5/8 stroke.  The pistons on each are level with the deck at TDC.   Each left the factory with a 7 to 1 compression ratio.

Given the larger volume of the 230's cylinder  how could it have the same compression ratio as the 218 if the chamber size was the same ?

Hollanders is correct only in that the heads are a bolt for bolt swap.      

A 53-4 parts book shows part number  1327008 for a P25  (218)   and 1326310 for a D46 (230)     and that's my client's case, your honour and he's sticking with it.

I object, speculation.....

[P15-D24]

Two things, if any of you have the 23' heads you think are different please post the casting numbers. 

Second if Greg G's observation is correct, then yes it would have a higher compression, but it has nothing to do with the head. 

[rekbender]

Early last spring, I compared the chamber volumes on three heads I had. The head numbers are listed by the blocks they were removed from and may not be correct for the blocks. Average chamber volumes were:

 

P2    head no.    632955-2         89.5 cc

P19  head no.   1311810-5       89.2 cc

D30  head no.   1120804-2       95.5 cc

D42  head no.   1326386-1       96.7 cc

 

The P19 and D32 heads had a different chamber shape - the chamber fit much closer to the exhaust valve and required a head gasket that fit accordingly.  I just checked a late 50's head no. 1676337-2 that I found two weeks ago. This is the 230 head with a nominal 8 to1 compression ratio. It's chamber volume averaged 75.4 cc.  From this limited information, it does appear that the 230 heads have a greater chamber volume than the 218's, although the late 50's head seems to provide a small increase in compression if used on a 218. I also cc'd a used  (compressed) universal copper head gasket and a used Fitzgerald 0587 head gasket that properly conformed to the P19 and D42 chambers. The copper gasket gave away an additional 4cc to the Fitzgerald so this seems to be critical when computing compression ratios. If anyone is interested, I can post pictures of the different chamber shapes and gaskets.

 

 

[greg g]

Yes please post the pictures.  I will pull out my Edmund's head and get pics of those chamfers also.  If I recall they were just about flat except for the valve chambers.

[55 Fargo]

Okay yall, have a looksy at this IND 265 head, its chambers are huge, the 265 has the "holy grail" of all strokes, its the Mopar Flathead King of stroke.

Now this head placed onto a 228 would lower compression big time.

Facts, when you increase stroke, and thr CC (head) remains the same, you increase compression.

This is not Fargo's armchair opinion, its Automotive engineering fact, Google it and see.

Tim Kings bury already documented on the other thread, that there are many many head designs, and compression ratios for these engines, from the early lower types, industrial type, and later high compression types.

[rekbender]

gregg g, the first five pictures below are of the heads in the same order as the list below. The D42 head is not labeled - it appears at the top with the P2 head below, and is the one that has just been cut. As a note, the D42 head was cut .090" - this resulted in an average chamber volume of 75.4, just a coincidence it's same as the late 50's LD1 chamber volume. As I remember, there was still over .100" clearance above the valves to the head so a  .100" cut shouldn't be a problem. With this much of a cut, I don't know what happens volumetric efficiency or how thin the head becomes. This was an experiment to find out if a shaved 230 head would raise the compression on a 218. Not enough of an advantage to justify the cost, especially if the universal copper gasket were used. Might be worthwhile on a 230 if the chamber doesn't become too restrictive - the computed compression ratio on a .030 over 230 with this head and the correct gasket was 7.8:1

 P2    head no.    632955-2         89.5 cc

P19  head no.   1311810-5       89.2 cc

D30  head no.   1120804-2       95.5 cc

D42  head no.   1326386-1       96.7 cc

LD1 head no.    1676337-2       75.4 cc

The last four are the difference in the way the gaskets conform to the chamber around the exhaust valve and between the combustion chambers.

 

Here are the part numbers I've seen for the tighter chamber head gaskets:

Felpro no.             7547  steel

Fitzgerald no.     0587  steel

 wizard no.          R6057 steel - actually a Felpro 7547

Victor no.             V1066   copper

Fitzgerald no.    0492     steel - for early non-internal bypass head

 

[Andydodge]

Dunno if this helps anyone, this is the chambers of an Edgy head.......regards, andyd 

[55 Fargo]

1 hour ago, Andydodge said:

Dunno if this helps anyone, this is the chambers of an Edgy head.......regards, andyd 

Help in what way as its not stock.

Its a nice head no doubt. Note the sparkplug hole position as compared to stock...