676337 head

[Lloyd]

I have a chance to pick up a head casting number

676337-1

Ive read on some older posts this is one of the higher compression heads on the late 230’s. 

My engine is a plymouth 1950 218 that I have stroked with a 230 crank. I re-installed the original 218 head with only a resurfacing done.

Question is would swapping out the original 218 head for this higher compression 230 head give me a higher compression ratio?

 

[Plymouthy Adams]

have  you cc'ed the heads?  this one and the one you had shaved that is on the block now

[Lloyd]

No. The 218 head is working on the engine. I haven't got the 230 head. I have to buy it. I just don’t know if it will give me a bit more or not and if there may be some things I should or could look at beforehand. 

From older posts I read these heads bumped a 230 up to 7.7-8. I believe by stroking my 218 I took it to a 230. 

So putting this head on should do the same?

[Adam H P15 D30]

There was a thread on here a while back where someone CC'd a few heads from 201-230 engines.  I think the intent of the thread was to determine some sort of unsurfaced base line but there were notable differences in the combustion chamber CC's.  I did a quick search and couldn't find it but there are differences.  I THINK the late 30's 201 heads had the smallest CC but not sure...

 

Adam

Edited June 8, 2018 by Adam H P15 D30

[dpollo]

My take on it is the chamber on a 218 head would be smaller than the same year's 230 to achieve the same compression ratio.

So keeping your 218 head on what is now a 230 would be ideal.   This is what I have on my 50 Plymouth and it works very well.

[kencombs]

On 6/7/2018 at 6:34 PM, Plymouthy Adams said:

have  you cc'ed the heads?  this one and the one you had shaved that is on the block now

This is the only real way to find the right answer.  After all these years, heads may have been swapped or milled.  I'm facing the same question.  I have a '56 Plymouth head, a 50 Plymouth head and an unknown that I think is a forklift take off.  I'm going to get me a large syringe and do some measuring on eof these days.

 

The calculate the chamber size needed to get to around 8.5 to one and mill one of them if needed, unless one of them needs no change, unlikely.

[Lloyd]

3 hours ago, dpollo said:

My take on it is the chamber on a 218 head would be smaller than the same year's 230 to achieve the same compression ratio.

So keeping your 218 head on what is now a 230 would be ideal.   This is what I have on my 50 Plymouth and it works very well.

 

That was my thoughts as well. But this is suppose to be the high compression head for a 230. I seen it on an early post and I think it took a 230 to almost 8. 

But yeah. I’ve already started reading up on cc’ing a head. Don’t look to hard. Looks like I’ll need a buret.

Couldn’t have told you what that was till an hour ago. 

 

Thanks. 

[kencombs]

3 hours ago, Lloyd said:

 

That was my thoughts as well. But this is suppose to be the high compression head for a 230. I seen it on an early post and I think it took a 230 to almost 8. 

But yeah. I’ve already started reading up on cc’ing a head. Don’t look to hard. Looks like I’ll need a buret.

Couldn’t have told you what that was till an hour ago. 

 

Thanks. 

Burrett would be nice, but a large syringe will work ok.  Should be able to get one cheap at a farm store that handle livestock medical stuff, or maybe smaller ones used for oral medicine dosage from a drug store.  Might have to refill but that's not a problem. 

[classiccarjack]

I purchased my burret from a medical supply store.  The funny thing is, it's like buying a gun, I had to wait 72 hours to pick it up....

 

Got to love California!!!  LOL

 

I also read that the later Heads had better chambers....

.

[dpollo]

57 to 59  230s had 7.7 to 1 compression  and  the 2 barrel engines were 8.2 to 1.

These heads can be easily recognized by the small hole fror the electrical temperature gauge sender.

 

part #s are 1822839   and 1821845

 

The number you cited  predates 1950  and this could be confirmed if it does not have the extra water passage at the front edge for the bypass.

[Lloyd]

2 hours ago, dpollo said:

57 to 59  230s had 7.7 to 1 compression  and  the 2 barrel engines were 8.2 to 1.

These heads can be easily recognized by the small hole fror the electrical temperature gauge sender.

 

part #s are 1822839   and 1821845

 

The number you cited  predates 1950  and this could be confirmed if it does not have the extra water passage at the front edge for the bypass.

 

Thanks dpollo for the information. But I’m not sure where to look for the extra water passage. I’ve only seen two heads. A 1939 201 and a 1950 218. The thermostat housing fit both. 

 

The numbers I gave were not part numbers. They are casting numbers. Looking at the numbers I gave I see I missed the first number. The correct casting number I’m asking about is:

1676337-1

using the first 7 numbers before the dash in a search brings up a few previous topics like this one .

 

[dpollo]

The bump for the water passage is between the front of the head and the back of the water pump.   If you have not seen this then your head is likely  1950 or earlier.

 

  The only exception to my knowledge is on the 51 and possibly later Spitfire engine

[Lloyd]

Heres a couple pics. First two is the 1676337-2 and the second one is the head on my 39.

I havnt got the head yet but from tte pic The only bump I see from this angle is the middle one where the head bolt goes thru.

[_shel_ny]

Bump at front for bypass.

 

 

[Lloyd]

13 minutes ago, _shel_ny said:

Bump at front for bypass.

 

Thank you Shelny, I've been looking for a picture of that. Its obvious the head I'm looking at does not have that bump.

 

Did some research on this internal/external water passage. I had seen it mentioned but did not know what it was about.

Whole idea of a bypass was to help provide for more even warm-up reducing hot spots plus let the warmer water come into contact with the thermostat sooner. Seems it removed the water connection on the thermostat housing and the water pump seen on early engines such as mine. So a different thermostat housing and top fitting for the water pump would be required. As far as water pump either type can be used but the backing plate may have to be swapped out to accommodate the extra port on the newer head.

 

Appreciate the input guys.

 

 

[greg g]

Don't forget when doing combustion chamber measurements there is a difference in where the top of the piston is at tdc.  The 230 piston is just a hair short of being level with the deck, while the 218 piston stops a couple 32nds shy.  That might be the reason the 218 chamber in the head needs to be smaller than the 230's to achieve the same squeeze ratio.  

 

Also the internal external thing has little to do with the age of the engine.  Based on observation I have seen a 36 coupe with external, and a fourdor sitting next to it with an internal set up.  My 46 business coupe had an internal with its original 218 set up.  It still does with the 56 230.  My friend is currently rebuilding a P23 labeled 218 that is internal, the 51/2 Dodge engine in his car has an external. Again no rhyme or reason obvious for which system and when it was assembled.

[Lloyd]

33 minutes ago, greg g said:

Also the internal external thing has little to do with the age of the engine.  Based on observation I have seen a 36 coupe with external, and a fourdor sitting next to it with an internal set up.  My 46 business coupe had an internal with its original 218 set up.  It still does with the 56 230.  My friend is currently rebuilding a P23 labeled 218 that is internal, the 51/2 Dodge engine in his car has an external. Again no rhyme or reason obvious for which system and when it was assembled.

 

Well Greg you just blew it out the water. I’m thinking since the head I’m looking at does not have the hump it must be pre-50.

Guessing the internal bypass didn’t start happening till later models. Possibly an upgrade in design from that point forward. So, the head I’m looking at might not be the high comp head I’m thinking it is. 

But you are saying internal or external was spread out thru the years from early on till late. So looking for the hump is not a tell tale factor. 

 

My engine is a 218 with a 230 crank so I’m guessing the piston should come up to about level with the deck. It has the original 218 head. I had my machinist resurface the Head but did not cc it.

Wish I would have checked all this before I put it together. 

Pulling a head on these engines ain’t all that much though and I would like to know what my CR is and then possibly look at bumping it up a little depending on what it is. 

[dpollo]

I can say with certainty the extra "bump" for the bypass first appeared in 1951 on all engines except the Spitfire series.

For proof, go to a listing of head gaskets.  While you can use the 51 and newer gasket on an earlier engine, you cannot use the earlier gasket on a later engine unless you block the bypass hole(s).     What has likely been seen are a mixture of newer and older  components .

[Lloyd]

So did any of the engines continue with the external bypass after 1951?

[greg g]

Perhaps,my 46 218 P15 number was original to the car based on what the original owner told me its is an internal set up with a bump.The 36 coupe belongs to a fellow I have been acquainted with to a dozen years and he is certain of his engine's originality. As observed yesterday, the external set up Dodge with no bump,but may be its a mongrel.

[P15-D24]

Might have some useful info, ymmv...

[dpollo]

2 hours ago, Lloyd said:

So did any of the engines continue with the external bypass after 1951?

Only the Spitfire (25 inch 251) in 51 and possibly 52.    

[Lloyd]

Well. Based on the chart above looks like they used a lot of the same casting numbers thru the years. Casting number 1676337 was used from 1942-1960. 

So if the high compression head casting to look for is 1676337 and it was used on the 1957-59 engines it would have to be one with the internal bypass (hump). And the chart does show this at the first line. 

 

Appreciate the help from all. I learned a few things.