Engine swap 24 engine 26 roadster

[Blairgr]

Hi Folks
I recently purchased a rebuilt 24 engine (July 24 according to the SN) and want to install it in my 1926 Roadster. What issues will I run into if any? I see the pedals are different and I’m not sure if the hog’s head are interchangeable. I have read that some of them are not and just want to see if this combination is or if it will even fit into the car correctly. If there are any complications or things that will need changed, I would appreciate the heads up before tearing into it.
Thank you

[DanTreace]

Quick answer is lots of issues if you only have a 24 complete block with 24 transmission, and no hogshead.

Your 26 would have the wide transmission brake drum, that uses the late 26-27 hogshead with the wide space pedals. And your floor boards are made for those wide pedals. Your 26 has the water outlet fan bracket, unique to 26-27. Your 26 will have the 4 dip pan.

Using a 26-27 hogshead on early block and transmission will affect the brake band operation.

The pre-26 have a 2 1/2" center to center pedal spacing for the narrow brake drum.

3" center to center on 26-27 wide drum hogshead to operate the wide brake band.

3 inch center 2627.jpg (99.93 KiB) Viewed 336 times

[ModelTWoods]

If your 26 has an original motor and transmission and just needs to be replaced for some reason, my suggestion would be to use just the rebuilt 24 short block using the 26 transmission, oil pan, and head with water outlet (or at least the outlet). That way, it is a drop in replacement and there's no trouble spots. My grandfather did this on his 27 coupe, back in the day, except he went a step further; he used only a 22 bare block from a salvage yard and used the 27 crank, rods, pistons, oil pan, and transmission. He did use the 22 head and front timing cover, mounting the fan down lower than the original 27 fans, but it worked. I have since corrected all these modifications.

[George House]

Howdy Gerald,… If I read your request for advice correctly, I understood you purchased a ‘24 engine, crankcase, tranny and tranny cover…since you didn’t reveal it as simply a ‘short block’. That right? If so, install it and change out the floorboards to fit the earlier pedals.

[Blairgr]

My apologies I should have been clear with my question. I have a 24 engine and transmission that was rebuilt by Ron's Machine Shop. I was unclear if I could just swap the hogs head but sounds like that's not an option. So I will do the engine transmission swap and change the floor boards. I attached a photo of the engine.

[speedytinc]

Floor boards will have to be custom made.
Consider changing/swapping the brake & low pedals.
Low pedal is a little bit of work to remove & re-rivet the cam. HH has to come off. Brake is nothing.
Then you still have what still looks like a 26-7 in the cockpit using original floor boards & mat.

Interesting, you have an early needle nose pan. Why??
You will have to use the smaller crank pulley. That will change designed fan speed & require a special size belt..

[Blairgr]

If I change the pedals will I still need to make new floor boards? I would like it to look correct if possible. Maybe I can find a used set of pedals so I only have to take one hogs head apart. I would like to get the original engine rebuilt at some point.

Interesting, you have an early needle nose pan. Why??
You will have to use the smaller crank pulley. That will change designed fan speed & require a special size belt..

The guy I bought the engine off of had this engine built for his grandfathers model T that he has so maybe the pan was to fit that car I don't recall what year it was.

How difficult will this be to get a belt that will fit? What diameter should the crank pulley be? I am not sure I can measure the one still in the car but can measure the one in the stand.

I appreciate the information. I guess I should have done a little more research before buying this engine. The 26 still runs just lower on one cylinder but fires right up and drives okay but you can feel the low cylinder going up hill.

[RajoRacer]

You can always swap out the crankcases - a few hours & gaskets !

[TXGOAT2]

Perhaps the engine in your car now only needs a valve job. Much easier than changing the engine and transmission.

[speedytinc]

If you change the pedals, your current floorboards/mat will not need modification.

You can use a string to determine belt length. Take the dimension to an auto parts store & get the closest length serpentine belt.
They come in different widths. get the widest possible. (about 1") thats an 8L width belt?
They may not have your length belt in an 8L. My 27 runs a 4L (1/2") Run the belt backwards (groves out)
You can also go to a bearing house & get a continuous flat belt to any length & width.

If you have the capability, I would change to the correct pan. (checked for straight) Why waste an early pan on a late T?
A 4 dip pan will make tightening the last rod easier down the road.

If I were doing this, I would retain the wide brake drum, modify the ears on a late HH to fit the early block or stay with a correct late block ideally. The correct "improved" power train is superior to the earlier versions. 4 Dip & HH bolted to the block.
It all goes back to your earlier decision to run this earlier engine. Not the best decision.

[speedytinc]

Perhaps the engine in your car now only needs a valve job. Much easier than changing the engine and transmission.

It would be worth looking into over the down grade of an earlier power plant.

[TXGOAT2]

The 1926 and '27 engine/transmission featured a much improved brake, and a more rigid connection between the engine and transmission as well as added braces from the engine block to the rear engine mounts, plus the wider pedals and easier transmission band service. The improved, more rigid block and hogshead design make for better and more stable 4th main bearing alignment. I suppose that your late coil box will bolt on to the earlier block and head. Being limited to the smaller, early crank pulley will cause your late style fan to run slower than it was designed to.

[Blairgr]

Man I thought it would be easier than all this. I guess a few options would be to stick it in and make it work while getting the 26 engine rebuilt or find a 24 to stick it in (always need another car) or build a speedster and stick the engine in that and drive the speedster while the 26 is down. I have wanted a speedster for awhile. Might be cheaper just to buy a car already restored and be happy.
Thanks for all the information.

[TXGOAT2]

What exactly is wrong with the engine in the car now?

[Blairgr]

It a little low on power when cruising with other T's. I have never had the engine rebuilt and when I got it the car the head gasket was on backwards so I pulled the head and one of the valves did not look good installed a new head gasket and it ran okay. As mentioned before one of the cylinder seems a little week and you can feel it going up a hill (the same cylinder as the bad valve). That was when I first got it and have driven it that way for several years. I did get the interior and paint done so the car looks great. I have not had the rear end apart and afraid the thrust washers might be bad and need to fix that.

Retirement is coming soon and would like to drive it more and have a little more confidence while out and about.

[TXGOAT2]

I would do a compression check. If one cylinder is significantly lower than the others, it is likely a valve that needs ground. A valve job is not very difficult or expensive. If a valve looked bad in the past, it most probably IS bad. Once a valve begins to leak, it will usually get worse, and it will never get better. There are simple ways to check the valves' condition without taking anything apart and the condition of the rings in the weak cylinder can also be checked without any disassembly.

[TXGOAT2]

The car does look great. There are ways of checking the condition of the axle thrust washers, and I'd want to do that before tearing into it. A weak cylinder is a nuisance, but if the axle goes bad, it disables the car entirely.

[George House]

Yes… beautiful roadster Gerald. You’ll have fun with its future performance. I agree with Pat. Refurbish and revive the ‘26 engine in situ. Primarily because pulling a ‘26-‘27 power pack is more of a pain than earlier engines. Starting with the headlight bar. I have a ‘26 roadster too. All body styles of these last 2 years tend to be sluggish. Once I achieved stock engine performance, I added an NH straight thru carb on a high volume aluminum intake manifold. Then I added a Scott Conger needle/seat and a Giant Power Head.It ran like a scalded ape but not being content, I also added a KC Warford tranny. I answered your OP by stating ‘yes you can’ but now encourage the ‘26 engine attention. And my roadster even has a painted radiator shell and nickel headlamp rims like yours.

[Craig Leach]

Hi Gerald,
Oscar Mike Golf. Look what you started! Just joking. Depending on your skill set you have a lot of options. You can put the 24 engine in & make
floor boards to fit the pedals, change the pedal trim, install the water neck & fan, find a belt that fits & install the coil box. I assume if you
where not comfortable rebuilding the engine or you would have when you had the head off? The 26 hogshead will not fit the earlier block &
swapping pedals around is sketchy as the 26 brake pedal is a collision issue because of the spacing it hits the hogshead well before it has enough
travel. Most all T parts can be interchanged if you are not going to do serious judging shows it just takes some ingenuity. If you can get the 24
engine in then you have time to do the 26 the way it should be done & you get to keep enjoying your T.
Craig.

[Blairgr]

Okay Well I guess I will start looking for a new project for the engine. Hope to find something in Ohio. Need to look into the valve job and see how that works on a flathead Model T engine. I have done them on over head valve engines years ago. If I had a way to pour Babbitt and align bore the block I would tackle the rebuild myself. My previous career I was a ASE master technician but that was 30 years ago. Still have the Snap-On tools and boxes Retirement is on the horizon and the barn will be getting insolated in September. Winter projects ahead.

Thanks for all the information
Gerald

[speedytinc]

You may not need new babbit. A tear down will tell. Many times shim removal & time saver will get the bottom end back to reliable/new.
A valve job can be done in place, except the last exhaust valve. The motor has to be moved forward on the frame.
Wise decision to retain the improved drive train.