The Stovebolt Site Forums The Shop Area Engine Shop Water pump adapter

Since I'm going to have to repull the motor from the firetruck and repair it, I'm going to address the location of the water pump and fan. I've noticed that it was in the lower third of the radiator on the 261 motor in the 1951 chevy. It seems to over heat so while the motor is out, I'm going to add the water pump adapter plate.

I guess my question is: can I use the 235 water pump with the adapter plate or must I have the 216 water pump? I've searched andread many posts but I'm not clear on which water pump should match up on a 1959-1962 261 motor and the adapter plate sold by Pre68Dave.

You need the 216 water pump.

You will need the balancer from a 54 or earlier motor, the 261 balancer is to big and will spin the pump to fast. Be sure to match the pulley width when ordering the water pump.

Thanks

Follow up question: Since I discovered my head was cracked in two places at valve seats about 1.5" in lenght would that lead to the overheating problems I had on the firetruck? I'd rather not drill into the head or block to install the waterpump adapter if replacing the head will keep my truck from overheating. Anyone have some advice or can answer my question? Thanks.

Bill

If you're going to be parading this truck, I would take every step towards keeping it cool that you possibly can. You may even want to add a pusher fan for back-up too,
Scott

Thanks. I wonder is over heating a problem for every 1948-53 chevy with a new radiator, water pump and rebuilt motor? It would seem to me "if" I've rebuilt it better than new, it wouldn't overheat as it had been doing. Am I missing something or was this truck built by chevy in those years a "natural overheater?"

Not that it's the whole cause of your problem, but if the fan on your new water pump isn't blowing in the center of the radiator it isn't helping anything. I would put the early pump on with the adaptor if it's overheating or not, but that's just me.

I put one of those adapters on the 57 235 in my 37,you do not have to drill completely through the block for the two holes as its only 3/4 and there is plenty of metal. Jeff

Thanks but isn't the 261 wall thinner?

I have put my adapter on several 261 and have seen no difference in the block thickness.

Second, the 261 balancer will work fine if you use a 1953-54 pump with a 3/8" belt. It is only the 1955-62 passenger car balancer you should not use.

I have had no reports of overheating with this setup if the timing is set correct.

Dave

Thanks!

Next question: Can I use the 18" 235 fan blade with the 216 water pump I just ordered? Or do I have to get a 216 fan blade? Thanks again.

Bill

Fans up to 1954 had a one inch center hole. They came in 16"(pass) or 18"(truck) sizes. The later fans have a smaller center hole.

The 16" fan is quieter and cools fine in most cases.

As far as overheating, early Chevies were noted to be cold-blooded, and never overheated if they were in good condition and properly timed.

Thanks!

Next question: I purchased a Walker brand Radiator Shroud to put on the 1951 firetruck with the 216 water pump adapter on a 261 motor. Anyone used a Walker shroud that has pictures, advice or experiance with Walker equipment or shround mounting?

Thanks

Bill

I don't believe converting to the earlier higher mounted water pump will cure overheating problems of a cracked head.
Get another head first before you drill and modify your block.
Fixing cracks on cast iron blocks or heads is really difficult and few welders can do that job right and reliable nowadays.

I'm a 'fan' (hoho) of the later style water pumps.
The later water pumps have the impeller actually right inside the block and are distributing the coolant inside the block more efficiently than the earlier type with the impeller outside of the block with only two small holes accessing the block. The earlier pumps have a smaller diameter pulley than the later ones, so they spin faster because of their inefficient impeller design, but this also invites cavitation at higher rpm.
I would always stay with the matching stock water pump to your block, just like the engineers designed it for good reason.

To center the later pump more towards the radiator, you can drill extra holes on the radiator mounts that are an inch lower and drop the radiator, which will also allow for longer more efficient fan blades, like the light efficient aluminum or stainless flex-a-lite (low profile) fans. That's an easier, more effective and cheaper upgrade than the adapter plate, in my opinion.
You get six blades and a lot more pulling power through the radiator at slow speed than the original fans.

The walker shroud will be great for slow driving, like in a parade.
Also good for lower rpm and speed city driving.
Not so good for high speed freeway driving though, when you want a clutch fan or no fan and shroud ideally.

Thanks. I just got a new head this week and I'm waiting for the waterpump and gasket set to arrive before rebuilding the motor. Here is the new 848 head picture: http://rides.webshots.com/photo/2658860960080243953WWcYQl

the 216 water pump arrived but it has the 5/8" pulley so back it goes. I checked and the 18" fan blade I have doesn't fit as the center hole as the fan hole is too small. What size fan blade actually fits on the 216 waterpump center post? Do I order a 216 fan blade for a 1951 or a fan blade for a 1953/54 water pump? Sorry but I'm getting frustrated...

How about a flex fan? It would appear I have to drill out the center hole bigger. I'm not sure drilling into a fan blade that will be spinning fast is a very good idea. Thoughts?

I'm running (every day) a 3/8" v-belt pulley "early" waterpump w/adaptor plate on my 1960-235 in a 54-3100 truck. I used the Flex-a-lite fan #FLX-1615P (Summit Racing equipment @ $24.95)....had to scribe over the 5/8" hole and carefully file out to 1" to fit over the 216/235 pump snout. No spacer is needed on my setup and I have a fan/rad clearance of 1/2-5/8".

The 15" fan clears all my pulleys (Alt, Harmonic balancer and A/c compressor), there is no vibration and the truck runs below the center peg on the stock gauge w/180 thermostat. I have experienced no overheating problems even with the a/c functioning. Also, I am not running a fan shroud.

If you are concerned about extended periods of idling and are considering an 18" fan, I would do a mock-up to insure you will not have pulley interference. The FLX-1615P fan has a center-mounted blade which gives me adequate clearances front and rear. A rear mounted blade, like is used on the flex-a-lite #SUM-G4918 or FLX-1318 will not clear your pulleys and there is not enough room between the fan/radiator to use a fan spacer if one were available. Hope this helps!

Dave

I've just ordered the same fan blade. I figure you live in Flordia and it must be hotter where you are. If it works for you, I'll take a shot at it.

Hot it is!!! I saw in your webshots album that you were trying one of the back-mounted flex-a-lite fan blades and figured I could save you some additional headaches. I tried several different combinations and through trial and error, have a combo that minimizes any overheating and clearance issues.

Care should be taken to use a sharp scribe and a good circle template to get the 1" hole centered around the stock 5/8" fan hole. I found that a couple rat tail files and some armstrong muscle made short order of opening it up. The fan is fairly awkward to grip for drilling and I just bolted on a piece of flat stock to two of the holes and steadied it in the bench vise.

The only down side of my arrangement is that in order to pull just the fan I have to remove the radiator. However, the pump and fan can be removed as an assembly should you ever need to change out the pump.

By getting rid of the short shaft pump with the big pulley and getting your fan speed within limits, and with the adaptor plate controlling the coolant flow, you should be in good shape for extended periods of idling at lower engine rpms.

My compliments to you on your album....I find that photo documentation and explainations are
a great source of information and I have learned much from the information shared on the "bolt". After all..."a picture is worth a thousand words!"

Thanks. I recieved the fan blade this morning and found a 216 water pump with the 3/8" pulley late today. I should have it all back together by noon on Friday. BTW: I'm going back to look at your webshot pictures but where did you mount the atlmeter bracket? Thanks for the help.

Pictures from today: http://rides.webshots.com/photo/2072326470080243953QyzZdm

I mounted the alternator bracket on the passengers side of the engine. I got the idea from one of the vendors that was selling a Dr. side mount that sandwiched between the thermostat housing and the block. My reasoning for fabricating this mount was so that I would only have to run one belt across my adaptor plate mounted waterpump. I'm running a 2 groove balancer and this minimizes the load on the pump bearings. I use the engine side groove for the water pump and the front groove to run the A/C compressor that is almost hidden, low on the drivers side. If needed, I can run a power steering pump above the compressor, off the front groove of the 2 groove compressor pulley.
It's been working great for the past year. I'm surprised that more folks don't work off the passengers side. The bracket was made out of scrap material and took about an hour to fabricate. Hope this helps.

Dave

I finally took the plunge and installed the adapter and water pump. I think I'm going to stay with the altmeter on the left side. Pictures: http://rides.webshots.com/photo/2102987950080243953eYqvdT

See it was not so bad installing the adapter,I had no choice on my 37 due to a water pump failure. The shaft came loose from the impeller and the hub went into the radiator,I had to break the water pump to get the radiator out but before I removed the radiator I tried installing the other short pump I had but it could not be installed with the radiator in place and I doubt the radiator could be installed with the pump in place so the adapter was the only way I could go. I did not want to have to remove the grille shell for every water pump replacememnt so the adapter was the only way to go for me and I could get rid of the electric fan as even with the short pump there was no room for a stock fan. Jeff

I want to say thanks as it really does center up the fan on the radiator! Pictures: http://rides.webshots.com/photo/2553588950080243953CIYuuP

Again, thanks!

I wish I had that much room between the fan and radiator in my 37,I have about 3/8 at the most and probably was the same when it had the 216. Jeff

I put the plastic radiator shroud on this morning but I hate it. It doesn't match the 1951 style... I think I'm going to go shroudless until I can find a real one or get one made.

Well after much discussion with the crew in the firehouse, I put on the fan shroud. http://rides.webshots.com/photo/2510026320080243953RdOFyp

As one of they guys suggested," lets put it on until we find an originial metal one." I guess I just can't argue with that logic! But I still do not really like it...

I think it will grow on you. It looks great! Nice job!

Thanks. I'm still trying to get it back together. Today I finished connecting oil lines, added water to the radiator, and made sure everything was properly torqued. Should try turning it over soon!

Well it hasn't been a good day... Water keeps pooring out from behind the water pump adapter plate. I've pulled it all out again. I'm going to need new gaskets so its going to be a while before I get it back together...

Always something... My wife suggests I sell it and move on... Taking a break...before I break something...

Just a suggestion....make sure that when you put the 2 bottom bolts in to secure the adaptor plate to the pump that you put the bolt heads on the inside with the nuts/lock washers on the outside. Reversing them will result in leaks. You shouldn't need any new gaskets if you used #2 permatex.

Ask me how I know this........Murphy's law in action!!!!

Dave

Thanks for the advise. I did that already but I'll try again...

I think I live with Mr. Murphy... :-)

I quit for today as it's my brthday(51) and I'm going to relax and start again in the morning.

Well...hap, hap, happy birthday....take a few hours off and give yourself a break. Heck, 51 you're just a kid!!!!! Wishing you many more!

I've installed several of the adaptor plates without incident and on my last install....for who knows why....I had the nut/lockwasher on the inside (towards the water jacket) and she leaked like a sieve! I'm a firm believer of #2 Permatex for any application that requires immediate torquing. I've found the RVT products work best if left slightly loose to set up and then tightened down. Not my choice for engine internals!

With all the work you've done on your truck (great album) you'll solve the problem in no time. And BTW....that's not a bad looking fan shroud.....it's got a retro look and sure will help out during long periods of idling. Keep up the great work!!!

Dave

Thanks. I had some cake, ice cream and a couple of beers so I'm rested and ready to try it again in the morning. Maybe I'll get it to stop leaking!

water pump adapter photos: http://rides.webshots.com/photo/2384423600080243953jOgxWT

I never felt like working on it today... Maybe on Saturday...

Just a word of caution...

Please check your oil filter connections.
It looks like you hooked up the full flow filter in reverse !!

Check the little arrows on the top of the filter adapter !!

Not sure how effective the filter is in reverse, but the bypass saftey valve would not work as it was designed.