250 in a 1969 trail grooming machine

[groomerguy]

I know zip about Ford sixes so bear with me. Our snowmobile club has a 1969 Bombardier trail groomer with a 250 in it. At least that's what's written on the valve cover. My info so far was it's a 240 Industrial engine. Apparently that is incorrect as it has an integral head and intake manifold. I did just replace the fuel pump in January and used one for a 240/300. The pump must be the same for the 250? I'm curious what the stock rocker arm ratio is and if there are different ratio rockers available that will increase my low end power without changing cams. I had mistakenly posted on the big block forum thinking it was a 240. The discussion over there is the Chevy 250 rockers (1.75:1) work on the 300 real well. Would they also work on the 250? The machine spends nearly all of it's time at 1800 to 2500 rpm and is constantly under very heavy load. It almost never exceeds 2800 rpm. It has an early model C4 behind it. I intend to do a valve job on it this summer and add headers since the exhaust manifold is warped pretty bad. I'm looking for a little more low end. I put a carb on it last summer from a 1986 F-150 300. It runs better now and gets better economy than the orginal carb. Any help would be appreciated. Thanks.

 

[Patrick66]

i think the stock ratio is 1.5:1, classicinlines.com sells high ratio rockers and headers.

 

[Bort62]

Ignition. Duraspark it if it isnt already.

I wouldnt waste money messing w/ rocker arm ratios... not going to make a very noticeable difference w/ a stock lift cam.

Since you are running at low RPM and high load, your best bet to increase torque while keeping the motor fairly stock may be to raise compression.

 

[XFlow_Fairlane]

does it have 3 or 4 bolts holding the water pump to the block? if it has 4 and is a 250 you could bolt a small block in it....

or you could also get a aussie 250 crossflow with a C4 bell and put that in it.

 

[groomerguy]

I installed a Pertronix ignition conversion a few years ago and it works great. I believe I'll go the Clifford header route this summer. The old exhaust manifold just won't keep a gasket in it. I've read + and - about the port divider here but I'll have it put in at the same time I get the valve job done just to help the gasket situation.
When I try to find parts for it at any of the "modern" parts places I have problems since I can't come up with a vehicle that had a 250 in it. Is this an industrial type engine?
By "modern" parts stores I mean the ones without books. They just go with the computer and start off by "What vehicle is is?" When I tell them it's a grooming machine they just get that blank stare like they see something off in the distance.
NAPA is about the only one so far that is still equipped to brose through books to find my parts. What did the 250 come in back in the 1969 era? Lots of info on this site. Thanks to everyone for the help.

 

[powerband]

When referencing parts, the last used 250's were in the 70'S Granada's (AFAIK). Most common use and references were Mustyang and Maverick years @ 68-72 (?) .


"Maximized" 250:

Port divider and work:

Headers are a good choice especially in the cold weather operation. If it is a 250 , the fairly common 170/200 Headers won't fit the Starter and FW/bell. Also, if typically under load, a simple $20 2BBl adapter and a good 2Bbl of your choice ( 5200 H/W, 2300 series etc) will work with headers to make efficient power .

250 W/ Headers and 170/200 set

I worked on equipment for a snow lodge. It had a Ford six powered tracker like you mention and a lot of Hedco (?) VW engined' snow makers. Ski-Minne in the Shawangunks' of NY's Hudson Valley .

 

[groomerguy]

Thanks for the pictures. Now I see how the port divider works.
The Clifford headers are more like shortys. I hope they fit. They are listed for 200 and 250. Are the ports or bolt holes different?
How do you post pictures like you did?
I replaced the orginal carb with one from a 1986 F-150 with a 300. It works better and seems to make a bit more power. Fuel economy is important too. Not too many gas stations out in the woods.

 

[wallaka]

Thanks for the pictures. Now I see how the port divider works.
The Clifford headers are more like shortys. I hope they fit. They are listed for 200 and 250. Are the ports or bolt holes different?
How do you post pictures like you did?
I replaced the orginal carb with one from a 1986 F-150 with a 300. It works better and seems to make a bit more power. Fuel economy is important too. Not too many gas stations out in the woods.

The heads are the same, the difference in the headers is to fit around the starter (which is in a different place).

There is a sticky (the first post) in the "Eye Candy" forum about posting pictures.