The Stovebolt Site Forums The Shop Area Engine Shop blocking heater hose holes in water pump

I have been trying to find a good used round heater core with no luck yet. Rather than running two heater hoses with a clamp on the ends I thought about just putting pipe plugs in the water pump where the outle/inlet holes are. Any suggestions?
Bill

Pipe plugs will work fine.

Gonna get cold up there this winter?

We always took one hose and routed it as a bypass. When I was young, I was taught that these engines needed the heater as a cooling system bypass that was needed to keep tht coolant flowing through the engine when the thermostat is shut. I don't know if that is true or not, but have continued the practice.

Considering that it was fairly common for trucks to be bought without heaters, I don't think blocking the connection holes is a problem.

It matters if you have a 261 and are running it with a 235 non-bypass thermostat, but for a 216 or 235 it doesn't matter.

4onthefloor, Why is the 261 different? How do you know if you have a 235 non-bypass thermostat? I have not put my rebuilt 261 back in my truck yet, but I installed a brass water shutoff valve in the heater hose outlet on my water pump, so I could shut off the flow to the heater during the summer. Will this be a problem? Here is a pic of the engine w/ the shut off valve installed: http://community.webshots.com/photo/109150147/120822879MhXjeY

oldblu49,

I am not sure what year your rig is, but the old heater cores were made of pretty tought stuff. Isn't there a radiator repair shop near you that could repair your core. If this isn't they way you intend to go, it might be fun to try and repair it yourself...if you fail, nothing lost.


Stuart.

Stuart,
Its a 49 Harriso heater. I have three of these round cores and two rad shops have given up on repairing or makng one good one out of the three. At the moment they are in a third rad shop awaiting inspection. And for tclederman, naw it won't get too cold up here. We are on the west coast and it seldom goes below freezing. One of Canada's hidden surprises!

The 261 is differant because of the siamesed cylinders and the steam holes in the head. It needs water flow through the head to avoid steam problems and head cracking, especially while the engine is warming up. The bypass thermostat has a basket type thermostat that sends water back to the water pump when closed, allowing circulation. It has a larger housing than the standard 235 type. You need a heater or a bypass hose if you are not using the big truck 261 thermostat housing.

Cujo8 - This is from an article in the tech tips section of inliners international. "In pure big truck form the 261 has a larger thermostat housing holding a double acting thermostat. This is designed to circulate water through the block and head before the thermostat opens to allow hot water into the radiator. Thus, no internal steam hot spots during warm ups, especially in winter. This is particularly important with very cold coolant. Vital engine spots can become very hot before the total coolant becomes hot enough to open a normal thermostat on the front of the block." You can tell it's a thermo housing from a 261 if it has 2 holes drilled for the smaller hose fittings in addition to the large one that feeds from the radiator. It is slightly larger than the 235 housing and it contains a hard to find by-pass thermostat. 4onthefloor turned me on to this for waterheating my intake and I couldn't be more pleased with the results. Thanks again!

A couple of other problems arise - finding that "hard to find thermostat" and the hose size change from the radiator to the housing.

Any suggestions on where to find wither?

Joe

One must always "Preview Post" to be sure the spelling is correct, mustn't one!

It should be: "Any suggestions on where to find either?" :confused:

Joe

hey Joe did you go to Oklahoma to the swap meet?.........Ronnie

Joe, the radiator hose fits my 261 housing as it did my old 235 housing. Being a 62, maybe it was different than what you've seen. I found the by-pass thermostat at a local parts plus. You have to get them to look in the industrial truck catalog. It helps if you have an old one to compare it to. Be aware, you must take measurements since the replacement doesn't exactly look the same.

Yes, Ronnie, I was up there Friday from about 10:00 am until about 3:00 pm. They had a full house except for the new area they have added on the far side of the grounds. A pretty good crowd, but not as much as last year on Friday.

I didn't see much Chevy truck stuff - one guy had an old dirty Offenhauser intake with two Rochesters on it, an old dirty Offenhauser valve cover and a home made split manifold that looked ok for $550.00. I stood there and looked at it for a few minuets trying to figure out how come it was supposed to be worth that much, walked away an bought some peanuts. Got a good deal on the peanuts!

The burger I had for lunch in the indoor arena lunch room was good!

I've been to Chickasha every year since 1985. This was not a memorable year.

Joe

doc -

I've been running a 235 thermostat housing and thermostat on my 261 for about 12 years. I thought the 261 housing took a larger hose, but you are probably right about it being the same size - it almost has to be to since all of the radiator necks were the same size.

I sure would like to see a picture - if any body has one - of that thermostat. I probably should be running that on my 261 for things to be totally right. Anybody got a picture from a box or have an old one you can take a shot of?

Thanks for the help and oldblu49, I didn't mean to hi-jack your post. It just got too interesting for me to pass up!! Hope it was OK! I'll shut up now!

Joe

Doctasuds or 4onthefloor, Can you tell from the picture I linked to above if I have the 235 or 261 thermostat housing? I also would be intertested in seeing a picture of the bypass thermostat you guys mentioned. Would drilling a few 1/8" holes in the thermostat help with this issue?

cujo8 - Here are some pics of my set-up. I think I may have some solo pics of just the thermo housing, but I have to find them first! http://community.webshots.com/user/doctasuds It appears that you have a 261 waterpump. That thermohousing is hard to see, but it looks like it's from a 235.

Cujo, You definately have the right water pump, just replace the extra pipe plug in the water pump with a nipple and run the hose from it to the "bypass" outlet of the thermostat housing. The picture is from the wrong angle for me to see the thermostat housing very well.

I think the thermostat for the bypass housing is Stant #13928 but please verify that before you install. I can't remember which hose nipple on the housing is the bypass. It should be the one that is blocked by the thermostat when it opens.

The thermostat from a bypass setup looks kind of like a sink strainer. It actually works like a switch rather than a block. It routes water to the bypass hose when cold and to the radiator when warm, and it blocks the bypass but not the heater when open.

There is a '58 Viking 60 for sale on ebay in commercial trucks item #4583211573. That is definately a 261 waterpump and thermo housing. The guy thinks it is a 235. I would bet that it is a 261.

That truck also has the factory PCV system on it, also scarce. It looks like the heater is hooked up wrong, I bet it only works when the thermostat is closed.

If anyone on this board buys that truck I would like the PCV system off of it.

On my 261 I could not find a basket type thermostat, and after looking at the housing closer, I found a crack so I did not use it.

I called Jim Carter and told him what I needed. He sent me a housing similar to a 235. Check out my webshots page below and see if I need to make any adjustments. This motor runs extremely well and has 250-300 miles on it to date.

I have a Langdon's thermostat housing spacer w/ a threaded water outlet installed on my 261 engine and I am going to use that outlet along with the one that is currently plugged on the water pump to heat my Offy 2x1 intake manifold. I am thinking that this will act as a "bypass" setup as long as I get the proper bypass thermostat installed.
I think I must have a 235 thermostat housing, since it only has one threaded heater hose outlet in it, so if I was to hook up a bypass-hose from the 2nd heater hose connection on the water pump to the heater hose connection on the thermostat housing, I would then not have anywhere to hook up my return line from my heater. Clear as mud :confused: .

If I indeed have a 235 thermostat housing on my 261, can I still install a bypass thermostat in it? or won't it fit in a 235 housing?

The 261 by-pass thermostat will definately not fit in your 235 housing. It seals in 2 places as opposed to one and comes with a separate interior gasket. I don't know if you need one or not. Hey 4onthefloor, I noticed that heater hook up as well. I don't think the circulation will work very well without the pump - maybe it will? I wish I lived closer to that guy. I would buy it for the motor.

After thinking about this further, I don't think I will need the bypass thermostat, since with the Langdon thermostat spacer setup for my Offy intake will act as a thermostat bypass.