Customs Flathead 6 or Slant 6 Swap for 55 Dodge Truck

Slants are great engines and can be made to go more than a flathead in most cases.
The 265 has a stroke of 4 3/4 tons of lower RPM torque.
Breathing is the boon of the Lheads.
They should respond nicely to forced induction.
Friend of mine built his 225 slanty 4 bbl headers hot cam and head work 20 years ago
In a Valiant goes like hell still...

 

Very doubtful your block needs to be bored, more likely the ridge is just carbon. I agree a Valiant with a hot slant six is a fun ride.

 

If I have to go through the work of cutting a firewall to fit a motor in a vehicle, I will not be installing any 6 cylinder. That is a lot of effort for such little gain. Gene

 

I guess to each their own Gene.
Some people like 6s and dont always want V8s i suppose.
I know of a few Slant 6s in P15s and no firewall cutting.
I have nothing against any engine choice as long as I gave the right to choose mine...lol

 

My coupe has a 6 in it, buy mine is in the form of a "V", as in V6. I didn't have to cut the firewall for it to fit.
Nice thing about hot rods are you can do whatever you want. Gene

 

Flatty all the way

 

Back in 1959 or 1960, I had two friends in our car club that had 1953 Dodges, one a 2dr Hdtp, and the other a convertible. The guys were close and they teamed up to swap in the larger engine into both cars, ( I am not certain of the engine size, but it was the larger block). Both engines ran the dual carb manifold and the split exhaust. One of the cars had a three speed tranny, and the other had an overdrive. The both sounded performed quite respectably.
I regret that I didn't pay more attention to Mopars at the time. They were pretty cars.
The 265 gets my vote.
Bob

 

Me thinks there has been an awful lot of hot rods with V8's that have needed the firewall cut. What car is it that they take the whole firewall out and turn it around backwards to make the V8 fit???????? Hmmm?
I would rather go through all the work to put something different in hot rod then some bland belly button like everyone else has. Nothing against the V8's though. LOL!

 

My 1 & 1/2 cents worth is stick with the flatty. The sound alone is special & i've known of folks beat'n them to death, but they don't die........

 

Hey all been enjoying the posts and comments.
No decision had been made.
Except no V8s.
No frame swaps or front clip jobs...lol
Slant 6 or 265 flattie.
Now which engine to go with?
Flattie direct swap, ( for the USA boyz Canada only used the long engines) so no issues.
The 265 will have a warmed up cam and my dual carbs and exhaust off my current engine. The head will be replaced or shaved for compression to about 8 to 1 or so.
The slanty would be stock except 2bbl and headers and maybe a cam.
Cost to swap in slanty maybe a 1500.
Rebuilding my 265 would be 2500.
Now thats if my current slanty is good as is and no rebuilding.
No to make a choice.
But which would pull better and have more power....lol

 

Made this video last night please excuse my crappy exhaust piping.
This is my tired 228.
A 265 would look identical but prolly 50 more hp and wsy more torque. The stroke is a half inch difference between a 228 and a 265.

 

Hey Rusty Oletoole got no pinion on this....lol

 

Okay anyone else besides Hobo Jim use a slant 6 in an old Dodge truck or hotrod?

 

John like your engine, just not a fan of all the billet trinkets.
I also have an Optima red, it looks much better hidden under the floor.

 

How in the HELL do you spend $2500 rebuilding a flatty six when you already have the speed goodies? And there is a good chance the block does not need to be bored. You must be planning on farming the job out to the local auto machine shop and paying full list for everything.

I know a woman who drove her 41 Dodge into the shop and drove out with a completely rebuilt flatty six for $3000 including re and re, machining the crank, boring the cylinders, new pistons and all new parts. This was a Canadian Dodge with the same engine you have in your truck.

Don't overlook the 40 cubic inch advantage the flatty has over the slant. I know the slant is a more modern design but I doubt it has the moxie to overcome an advantage like that, especially as the flatty has a little of this and that to modernize it.

I can see you falling in love with the slant for some reason, doing a lot of extra work and going to a lot of extra expense, to have a motor that is almost as good for your purpose as a flatty. The long stroke high torque engine works so well in a pickup.

 

I personally think the slant six would give you more power right out of the box with the potential for a lot more power down the road


Sent from my iPhone using H.A.M.B.

 

1954 Windsor 265 six, 119HP@3600 RPM Torque 218@1600 RPM

1969 Dodge 225 slant six, 145HP@4000 RPM Torque 215@2500 RPM

Notice the slant six has more HP but less torque, and both HP and torque are developed at higher RPMS.

I believe with higher compression, dual carbs, dual exhaust and a cam the flatty will beat the slant without losing the advantage of broad powerband and low RPM torque.

But really there is so little difference either will work.

 

Okay Rusty im all ears?...lol
Now a rebuild, im.not talking a valve grind and ring job.
I mean all out, boring decking block, new guides polish crank etc. Cam grind etc.
Hell on the cheap the parts alone are near 1200 usd convert to canuck and you know what I mean.
2500 for a rebuild complete is fairly modest some pay 3500 to 4000 right in the USA.
The woman with the 41 Dodge how long ago was that? The last 10 years prices have gone up.
But im all ears and open to suggestions..

 

Although i love my flatties the slant 6 is a superior design hands down in my belief.

Rusty the 225 even in 69 was not likely to have the advertised 145 hp that was totally overzealous. With a 1 bbl more like 105 hp.
But they will make power there is no doubt but it aint cheap either I reckon

 

The woman was Lizzie Maine, a movie theatre manager from a small town in Maine. She drives a Canadian made Dodge which she calls a Plodge because it has a Plymouth body.

About 4 years ago she drove it into a garage and had them remove, rebuild and reinstall the engine. They could not believe it arrived under its own power because of the broken pistons and general wear and tear. But the car ran and did not even make any fuss about it although it was sluggish and down on power.

She told me the bill ran to $3000. At the latest report she has 11,807 miles on the rebuilt engine, 102,989 on the car. Runs fine, burns no oil, all the power she needs.

http://www.thefedoralounge.com/thre...nd-parts-requests.48791/page-158#post-2340823

I don't know why you want to do all that work. Have you checked and measured and found out if it needs it? If the cylinders and crankshaft are not worn there is no point in truing them up.

 

November 2012
Report from the garage on the State Of The Plodge -- the guy calls me this morning and the first thing he asks is "how long has this engine been running like this?" Turns out that along with the broken piston, every piston ring on the other five pistons was broken -- he was astounded there was any compression at all. I told him I was easily able to get the car up to 40 mph, and he says "were you attached to a tow truck?"

Be that as it may, though, he has the engine all apart and the rebuild should proceed with no complications. If there's any doubt that Mopar flatheads are the most indestructible engines ever built, this ought to put that to rest.

Scroll down to post 927. Interesting Plodge progress report, and Lizzie swoons over a Franklin
http://www.thefedoralounge.com/thre...and-parts-requests.48791/page-47#post-1548172

 

Hi Rusty yes have not measured the cyl bores yet or pulled it completely apart.
Heres why, I have 2 other 265s in the wings off combines In Sask.
1 is supposedly a rebuild with very little usage.
The Gent who contacted me will check them out soon.
His 88 yo uncle owns them and the farm was sold. So waiting word before I five into mine.
If its another story will tear mine down.
And yes i have cyl ridge not carbon build up so wear is there.
Overall engine was clean cyls glazed and a tiny but if scoring and 1 had some surface corrosion. Valve chambers clean.
Cam lift nothing special .375 lift duration unknown head has huge low compression CCs..Stay tuned.

Rusty how would a 228 perform.compared to a 265?
I have driven engines with 218 228 250 none fresh rebuilt though.
Im.hoping a 265 has a lot more power than a 228.

 

218 97HP@3600 Torque 175@1200. Yours is probably less due to wear and low compression.
265 119HP@3600 Torque 218@1600.

In stock condition the big motor had about 25% more HP and torque. Your engine, hard to say, you know it is worn but it also has the hop up accessories. If I had to guess, I would say a fresh 265 would have twice the power you have now. If your present engine has 75HP and a fresh 265 with accessories had 150HP. It would feel like a lot more than that right through the rev range.

I had the impression your 265 had been rebuilt and then had very little use. Now I see this is not so. I guess you won't know what it needs without taking it apart. If you do the rebuild yourself it will be closer to $1000 than $2500 even if it needs to be bored.

 

I removed a good running 265 flathead from a 48 bob truck. Was gonna install it in a 1944 WC dodge army vehicle. And the 265 being longer would have been a lot of modifying to make it work. So I took the 228 from a running driving pickup Truck and used that. Its possible the pickup will some day get the 265? But ive got this 440 and auto trans setting here? I wouldn't waste time on a slant six.

 

228 and 265 is the same block.
Do you mean a 217 or 230 23.5 inch engine?
265 should pull better than a slant 6?

 

Not that it matters much my engine is a tired 228..

 

228 would have about 103HP @3600 and 190 Torque @ 1200

 

The bob truck engine was a few inches longer than the original WC and the pickup engine.

 

Yes if course they are shorter there US built 217 and 230 engines.
In Canada all Mopar flathead 6s were the longer blocks, in a number if displacements 201, 218, 228, 237, 241, 250 and 265 all used same block.
Lucky for us when swapping in bigger engines a direct bolt in...

 

Have a look at this Rusty and any of you others who are interested.