rebuilding 265 flathead

[mpn23748]

I have been reading post off and on here for a while, I thought I would ask some opions. I am currently rebuilding my 265 from my 1954 (Canadian) Desoto, here is a list of what I have.

1-265 long block full flow oil system

2-Edgy head and camshaft

3-edmunds twin intake

4-Langdon headers

I would like to rebuild this so it will last, it will not be a racer, but will get driven long distances, and get the ocassional hard drive. the car has a 2 speed powerflite Auto, I have installed 3.23 gears.

1-should I line bore?

2-should I balance the rotating assembly

3-what about the modified oil system I have read about,do I widen the main bearing oil grooves so they match the block hole size.

Any tips would be appricaited, thanks

[greg g]

A line bore couldn't hurt, balancing is probably a good idea and as it isn't an expensive proposition should be considered. There has been some discussion about cross drilling the crank for more oil flow but this has usually been recomended for engines that are going to be turn a lot of RPM's 5000 + on a regular basis. I believe a couple of fellows have rebored and then gone to different pistons of a more odern design. Some have suggested porting the block to match the gasket openings. Lightening the flywheel could be considered as it will help build rpms quicker.

Sounds like it will reliable engine.

[hkestes41]

Will all your goodies fit the 25 inch block?

[mpn23748]

Yes, all my goodies are for the long block, I actually have two of everything as I also have a 48 plymouth (Canadian car Long block) that I will be putting a 265 into as well

[48Chrashler]

good luck. I am in the midst of my 251 (250.6) rebuild.

I want a daily driver and occasional highway miles so I decided to upgrade rear end ratio and tranny rather than engine mods. I have gone to the split exhaust and looking at dual 1bbl carter carbs.

I did not know Langdon made the longer block manifold.

[mpn23748]

the langdon headers are a modified shorty steel tube header.

[Terry in Bozrah]

What Cam will you be using with the 265?

I just love my 230 with the full race cam! Lump Lump Lump.......SWEEET!!!

I also will be re-building one(265) for a Military WC pick up.

It's a little 1/2 ton and I think that this babies going to fly with the 265 in it.

Port your head(CC) and open exhaust to gasket size.

Increase you flow. Index your plugs.

Clean twice with hot soapy water than do it again.

Get those long wire brushes and clean all the oil passages.

Do you have any pictures of your set up?

The Powder Coating didn't do so well? Need to repaint.

Terry

[greg g]

Splain porting the head..... isn't portig done to the intake and exhaust passages which ar in the block. Typo???

[42PlyDeluxe]

Very nice looking motor

[mpn23748]

here is a pic of my car and my motor,

cam specs are:

260 duration

222 @ .050

109 centerline

.410 lift

[Terry in Bozrah]

When I ported my block, I used the manifold gasket as a template and marked manifold to block. I tried to get everything to flows as one.

I had the head shaved, I think it was 1/8 or 1/4?

Cleaned up the flow area.

Sometimes I'm to fast on the guns with a reply.

Like a kid in a candy store.

Can't really see much but ports are matched.

TK

http://photos.imageevent.com/terryandlinda/dumpbedncrank/large/9156-R1-20-21.jpg' alt='9156-R1-20-21.jpg'>

[No Bux Rod]

Greg g

What more modern pistons have you seen in 265s? The almost 2" compression height makes a match tough with stock rods. The only ones I have found is a custom set from Ross at about $100-$125 ea.

N B R

[greg g]

Send a PM to member Marty Bose, I believe he is running some alternate pistons.

[martybose]

Send a PM to member Marty Bose, I believe he is running some alternate pistons.

I sent a stock piston, a set of rings and a requested bore size to Venolia and they made me a very nice set of custom pistons. This was quite a while ago, however.

Marty

[greg g]

What will your bore diameters be after you machine the cylinders??? Just looking at a /6 page and they mentioned several different pistons, From Vega, to newer metric ones, they also mentioned those from the mopar 2.2 turbo 4 cylinder. Don't know how they would work with your pieces but you should be able to find something throughthe machine shop the matches the pine placement and the new bore.

http://www.slantsix.org/articles/stroking/stroking.htm

[Normspeed]

mpn, that is one nice looking DeSoto.

On my short block, the shop did a line-hone, a bit less $ than a line bore because it was aleady close to being right. I had it balanced by the same shop.

[grey beard]

Here's whar I've learned about engine building. I've built a bunch, and a few flew apart. I''ve learned a lot in the process.

Anytrhing you can do to an engine in the way of blueprinting the specs - like balancing rods, pistons and reciprocating parts - will help the engine live longer and happier.

Anything you do to an engine to make it pump air better - like increasing bore, stroke, valve size, valve lift, porting and polishing - will make the engine more powerful and responsive BUT will also help make it wear out faster. This is true because you are putting more load on the bearing and piston surfaces and creating more combustion chamber presssure and - most likely - engine rpm.

If your goal is to build an engine that will last the longest hours or miles, build it stock, blueprint it as much as you can afford, and use it within its normal rpm range. Give it lots of good maintennance - filters and fluid changes. Get it up to operating temperatures fast and keep it there till it is shut down.

The longest lasting reciprocating engines I have ever seen in my life are in Ohio River tug boats. Used to take my diesel tech college class to their dock on field trips. Those two stroke 900 rpm GM locomotive V-12 diesel engines were started up only after oil had been circulated through them 15 minutes by an electric oil pump. They were never overspeeded. They were merticulously maintained. They worked their hearts out year after year, and in the process wore out pistons, rings and cylinders, which were easily replaced in the field. When these engines are shut down, oil pressure is maintained until the oil temp is back to the same as that in the reservor.

No one knows how long the lower units on these engine will last, for none have ever worn out, to my best knowledge. They just keep on going. Many are over fifty years old - still original bearings and rods. Never saw anything like it in my lofe.

[James_Douglas]

I found his steel headers to be not-acceptable and sent them back. Headers work off of pressure waves and his had one tube, of the original four, cut and welded in such a way as to cancel out the sonic pulse which defeats the purpose of having a header.

Look for something of better quality is my advice.

James

[Don Coatney]

My car is a 1948 P-15 Plymouth. I have a .030" overbore in my long block Desoto 251 CI (now 255 CI) engine. I am using shiverlay valves. I have an Edgerton regrind can to the same specifications you listed. I have the full flow oil filtering system. I am using the stock head with dual Carter B&B's, dual exhaust, and a dual point distributor. My manifolds are modified stock units. I have a T-5 five speed overdrive transmission pushing a 3.55/1 differential. I can cruse all day long at 70 MPH and my engine is truning around 2200 RPM's. I have driven my car around 25,000 miles with this setup and it is very dependable.

I hope your engine can pull the 3.23/1 gears as they seem a bit steep espically with the heavy Desoto. What size tires will you be using?

[mpn23748]

Don,

I have 215/75R15 tires on the car I put 3500 miles on the car last summer with the 3.23 gears, it is no race car from a dead stop, but it is alot nicer when cruising on the highway. Where could I get a dual point distributor are they 6 volt, thanks

[greg g]

Distributor doesn't care about voltage, it's just a switching device.

[Don Coatney]

Where could I get a dual point distributor

They are an aftermarket conversion kit and occasionally they come up on the bay. Or you could post a querry here on this forum with dual point distributor wanted in the subject line.