Long block engine number

[Mickkc77]

First time posting. My new toy is an Australian built 1956 Plymouth Cranbrook Ute. She appears to have had an engine swap at some stage as she's a base model with standard shift, 3 speed column shift. This I thought would have had a 23 inch 230 six. I measured the head and it's about 25.5". So that makes it a 251 or 265. Most likely 251cid.

The engine number on the left side at the front just below the head is:

V 63I259P 

I've Googled all sorts of things with no results. Can anyone shine some light on this?

[Dozerman51]

That is probably a rebuilders number. 

[Mickkc77]

Doberman51

OK I didn't know they stamped their own numbers. I guess things were a lot different way back when these old cars/motors were much more common.

I'm going to have to pull the head off then to measure the bore and stroke to see what I've actually got?

[HotRodTractor]

21 minutes ago, Mickkc77 said:

Doberman51

OK I didn't know they stamped their own numbers. I guess things were a lot different way back when these old cars/motors were much more common.

I'm going to have to pull the head off then to measure the bore and stroke to see what I've actually got?

 

Actually there is a plug on the head above the #6 cylinder that you can use to measure the stroke. All the bores are the same per length of the engine block (other than oversized) - so you will at least be close and know what it started life as.

[P15-D24]

This might help. 

 

[Mickkc77]

 

Thanks, that's a great idea, I knew about that bolt over No.6 cylinder but never worked out what use it was, except maybe finding TDC.

Thanks for the reference file, I'll check it on my home computer and it might decode some numbers for me.

Cheers Mick

 

 

Edited November 2, 2018 by Mickkc77

[Jomani]

Could also be a 237 with a 4.25” stroke. I had never heard of a 237 until I checked the stroke on mine using a piece af brazing rod. TDC to BDC will give you an accurate reading on #6.

 

[lonejacklarry]

How would one measure the stroke with the head off of the engine with basic tools?  If there is 1/4" bore difference between the 218 and the 230 where would the piston be at top dead center on each?

 

Obviously the piston cannot come up higher than the top of the block.  So would the 230 come up even with the top of the block and the 218 come up 1/4" short of the top of the block?

[HotRodTractor]

2 hours ago, lonejacklarry said:

How would one measure the stroke with the head off of the engine with basic tools?  If there is 1/4" bore difference between the 218 and the 230 where would the piston be at top dead center on each?

 

Obviously the piston cannot come up higher than the top of the block.  So would the 230 come up even with the top of the block and the 218 come up 1/4" short of the top of the block?

 

The piston may or may not be slightly above or slightly below the deck surface at top dead center. You need to measure the distance the piston travels up and down in the bore - that is your stroke.

Edited November 2, 2018 by HotRodTractor

[lonejacklarry]

Thank you.  Your reply makes perfect sense.

 

[Jomani]

On 11/2/2018 at 6:10 AM, lonejacklarry said:

How would one measure the stroke with the head off of the engine with basic tools?  If there is 1/4" bore difference between the 218 and the 230 where would the piston be at top dead center on each?

 

Obviously the piston cannot come up higher than the top of the block.  So would the 230 come up even with the top of the block and the 218 come up 1/4" short of the top of the block?

 

The stroke is determined by the crankshaft - the longer the “throw”, the longer the stroke. To ensure that the piston tops out as close to deck height as possible, a crankshaft with a shorter throw would have longer rods - longer throw would have shorter rods. Generically speaking, since these flatheads generally used the same bore (depending on block size), the various cubic inch difference was obtained by increasing/decreasing the throw of the crankshaft and inversly increasing/decreasing the length of the rods.

[Mickkc77]

OK new problem. I removed the bolt over No.6 cylinder and tried to put a wire rod down it. It seems blocked? Not sure if it's been welded up or half the bolt snapped off in the bottom of the port? The bolt that came out is about 15mm long with about 10mm of thread on it. Any ideas? 

[Jomani]

Could be carbon buildup. You might need to try poking with something a little harder. Just be careful. On top dead center, the piston is very close.

[Merle Coggins]

Yes, likely just carbon build up in the hole. Poke through with an awl, or similar. Also, the “bolt” you refer to is an 1/8” pipe plug. 

[Don Coatney]

As Merle said the hole is most likely plugged up with carbon.

 

 

1/8" tapered pipe plug

 

 

 

 

 

[Mickkc77]

OK Don Coatney, I got the right place. Thanks for the pictures. The motor is supposed to be rebuilt by the guy 2 owner back. Last owner told me she was a smooth quiet runner with just a puff on cold start up. I tried lightly taping a 1/8 nail down it. No luck. Got check TDC and then maybe a tap or easy-out? Don't want metal going down the bore. 

[Andydodge]

Mick........how sure are you regarding the year of the Ute as your Mickkc77  on the side says 1954 yet you say its a 1956...........is there something with the P..? on it?...........on a plate on the firewall..............it should be P25S/1/2/3 or4...........tho' it seems that this number was used from 1954 thru to 1956.............also are the pedals thru the floor or hanging?.....chromed hooded headlight surrounds?............got a pic?............I know with the 1957 On Royals both the 23" AND 25" engines were used, which one depended on whether it was a standard 3 speed, 3 with overdrive gearbox or the Powerflite then Torqueflite auto.......I have not heard of Oz engine rebuilders stamping their OWN engine numbers as here in Oz the engine number was used by the Rego authority as the means to help identify the vehicle..............new engine numbers were/are issued by the Oz Police as far as I know still, not engine reco shops.............BTW..where are you.......I'm in South Grafton, north of Coffs Harbour........... NSW........andyd

Edited November 7, 2018 by Andydodge

[Mickkc77]

Andydodge

Build year confusion was as the last owner advertised it as a 54. (It is very similar style to an American 54 Plymouth sedans). I've since found info on the net saying they were first sold in Sept 56 through to 1958 The sedans started in 1955 to 1956, with the Royals starting in 1957. 

Build plate has  P25U - 2 - 275 

Pedals are hanging.

Hooded headlights, but it also has a spare set of steal headlight rings (non hooded).

The motor has my stumped, I thought with a standard 3 speed it would be a 23" 230, but after measuring it's got a 25" 251 with a strange engine number. Probably not the factory motor.

I'm in St Marys NSW.

Cheers Mick 

[Andydodge]

Mick, my info indicates that the hanging pedals and hooded headlights make it a 56 also, the 53/54 Plymouth body was used basically as the basis for the Royals which were made up to 1962, the Royal Wayfarer Utes didn't come till the AP2 which was 1959 so maybe the Plymouth Ute was on the market till 57 or 58 even tho' its a 56 model..........BTW I used to work in St Marys, at the CES which was in Queen St, we lived in Springwood 1981 to 1992 then moved to Grafton........got a pic?..............also the car side of the Forum would be interested in seeing it also...........if you need info email me at scaleautomobilia@hotkey.net.au or phone 02 66 425963 anytime............regards, Andy Douglas  

[Mickkc77]

Douglas

I'm not great on this technology, but I try posting the pictures I have. I'll get some more this weekend. She needs lots of work, but I love that it's a ute and so rare. Last pic is my 56 Desoto, which is going to a new home soon.

Edited November 8, 2018 by Mickkc77
Doubled up by mistake

[Mickkc77]

Needs lots of work ,but she'll make a great cruiser. Next job is to pre lube the engine for an initial start up after it reported rebuild and standing/storage for over 12 months.

[Mickkc77]