L76 Pulleys for Power steering

[George C.]

Hi all,
I am struggling with my Borgeson conversion kit installation and need some help.

My car is an L76 365 HP car I do not see anything in the AIM to assist me here, but I guess that shouldn't be a surprise since Power Steering wasn't an option with L76. The car does NOT have A/C.

My 2 groove crank shaft pulley is part number 3858533 which shows correct in the AIM, for my L76 motor. My 2 groove water pump pulley is part number 3995641, which is not shown in the AIM, but is working well with current CS pulley, and the alternator. The idler pulley was previously removed.

The new third groove pulley I bought from my local Chevy dealer is part number 3751232, it has a depth of 1 7/8" which is not deep enough to sit flat on the 2 groove crank pulley. I can also see the difference in the depth of the grooves

I have found another thread on this subject that suggests my new third groove pulley, part number 3751232 is compatible with the 3850838 crank pulley, but no information about compatibility with the 3995641 water pump pulley.

I am guessing many people have installed this Borgeson kit successfully.
Can someone tell me if I switch to the 3850838 2 groove CS pulley will that alleviate my problems? Or is there a different 3rd groove pulley that is compatible with what I have.

Thank you,
George

[Joe L.]

Re: L76 Pulleys for Power steering

George------

First of all, I am out-of-town so I'm operating completely from memory. Second, I have no knowledge of the Borgeson kit. If it's essentially the same as GM, then my responses below will apply.

First, the 3751232 crankshaft add-on ("third groove") pulley is definitely not compatible with the 3858533 crankshaft pulley.

The GM #3995641 water pump pulley is definitely NOT the original pulley used for your application. I just don't recall if it's a replacement pulley for your original but I don't think it is. If so, this could be a problem.

The original power steering pulley configuration for a C2 SHP application would not have used an add-on crank pulley. There would have been just 2 belts. The pulleys would have been deep groove. As I recall, one belt would have encircled the water pump pulley, crank pulley, and alternator . The other would have encircled the water pump, crank pulley and power steering pump. The power steering pump pulley would have been a "drop-down" style, single groove, cast iron pulley.

One more thing. If you have a 6 quart oil pan installed on your engine (as-original), it will not work with power steering (assuming this is an original-style power steering set-up). In that case, you would need to change to the 5 quart pan.

[George C.]

Re: L76 Pulleys for Power steering

George------

First of all, I am out-of-town so I'm operating completely from memory. Second, I have no knowledge of the Borgeson kit. If it's essentially the same as GM, then my responses below will apply.

First, the 3751232 crankshaft add-on ("third groove") pulley is definitely not compatible with the 3858533 crankshaft pulley.

The GM #3995641 water pump pulley is definitely NOT the original pulley used for your application. I just don't recall if it's a replacement pulley for your original but I don't think it is. If so, this could be a problem.

The original power steering pulley configuration for a C2 SHP application would not have used an add-on crank pulley. There would have been just 2 belts. The pulleys would have been deep groove. As I recall, one belt would have encircled the water pump pulley, crank pulley, and alternator . The other would have encircled the water pump, crank pulley and power steering pump. The power steering pump pulley would have been a "drop-down" style, single groove, cast iron pulley.

One more thing. If you have a 6 quart oil pan installed on your engine (as-original), it will not work with power steering (assuming this is an original-style power steering set-up). In that case, you would need to change to the 5 quart pan.

Joe,
Thanks very much for responding.

First the easy part, the Borgeson kit uses a modified Delphi steering box, so no issues with the 6 QT oil pan, no old style steering ram.

The water pump pulley fits and the belts are aligned, but the AIM does call for that pulley to be a 3770245, I don't know if mine is a replacement #.

The Borgeson pump mounts just like the GM one did, and they send a cast iron 2 grove pulley. The outer groove would align with a 3 groove pulley on the crank, if one were available that was compatible with the 3858533, the inner pulley aligns with the outer pulleys on my current crankshaft and water pump pulleys.

Someone suggested I do it with part numbers for the L79,if that is the only solution I must replace every pulley on the motor.

Maybe it is time to call Borgeson, I was thinking it would be easy to find someone on NCRS or the Corvette Forum that had already installed one of these kits on a 65 with L76.

Thank you again,
George

[Joe L.]

Re: L76 Pulleys for Power steering

Joe,
Thanks very much for responding.

First the easy part, the Borgeson kit uses a modified Delphi steering box, so no issues with the 6 QT oil pan, no old style steering ram.

The water pump pulley fits and the belts are aligned, but the AIM does call for that pulley to be a 3770245, I don't know if mine is a replacement #.

The Borgeson pump mounts just like the GM one did, and they send a cast iron 2 grove pulley. The outer groove would align with a 3 groove pulley on the crank, if one were available that was compatible with the 3858533, the inner pulley aligns with the outer pulleys on my current crankshaft and water pump pulleys.

Someone suggested I do it with part numbers for the L79,if that is the only solution I must replace every pulley on the motor.

Maybe it is time to call Borgeson, I was thinking it would be easy to find someone on NCRS or the Corvette Forum that had already installed one of these kits on a 65 with L76.

Thank you again,
George

George------


The GM #3995641 is not a replacement for the GM #3770245.

I just don't recall the small block cast iron power steering pump pulley being a 2 groove. The big block cast iron power steering pump pulley was a 2 groove.

I don't see you having to replace every pulley on the engine. The 3858533 crank pulley was used on most 1965+ SHP small blocks. Your alternator pulley may also be usable. I think what you need is a reproduction of the 3770245 water pump pulley and the correct small block cast iron power steering pump pulley.

Keep in mind that there are, basically, 2 pulley sets: standard groove and deep groove. The SHP small blocks used deep groove pulley sets (except some also equipped with A/C). You cannot mix pulleys from the 2 sets. The 3770245 and 3858533 are deep groove pulleys. The 3995641 may also be a deep groove pulley (I just don't recall this, for sure). However, if it is, I believe it's somehow different than the 3770245 and not a replacement for the latter.

Basically, I think what you need is the L-79 pulley set which, for the most part, is the same as L-76.

[George C.]

Re: L76 Pulleys for Power steering

George------


The GM #3995641 is not a replacement for the GM #3770245.

I just don't recall the small block cast iron power steering pump pulley being a 2 groove. The big block cast iron power steering pump pulley was a 2 groove.

I don't see you having to replace every pulley on the engine. The 3858533 crank pulley was used on most 1965+ SHP small blocks. Your alternator pulley may also be usable. I think what you need is a reproduction of the 3770245 water pump pulley and the correct small block cast iron power steering pump pulley.

Keep in mind that there are, basically, 2 pulley sets: standard groove and deep groove. The SHP small blocks used deep groove pulley sets (except some also equipped with A/C). You cannot mix pulleys from the 2 sets. The 3770245 and 3858533 are deep groove pulleys. The 3995641 may also be a deep groove pulley (I just don't recall this, for sure). However, if it is, I believe it's somehow different than the 3770245 and not a replacement for the latter.

Basically, I think what you need is the L-79 pulley set which, for the most part, is the same as L-76.

Joe,
Thanks again, and what you say makes some sense.

Looking at the two pulleys I would say the 3995641 is not a deep groove pulley. And I headed down the path of adding the third pulley to the crank thinking that was the best solution.

I will try to locate a 3770245, and an L79 P/S pump pulley.

Thank you,
George

[George C.]

Re: L76 Pulleys for Power steering

Joe,
Thanks again, and what you say makes some sense.

Looking at the two pulleys I would say the 3995641 is not a deep groove pulley. And I headed down the path of adding the third pulley to the crank thinking that was the best solution.

I will try to locate a 3770245, and an L79 P/S pump pulley.

Thank you,
George

Joe,
I looked at the pulleys again this morning, did a little research, and it appears that the 3995641, is a deep groove water pump pulley and was used in some 64-65 SHP engines. Sorry, it looked like a shallow groove with my worn out eyes last night.

I have further been able to identify that the P/S pump pulley from Borgeson is a part number 3878245, which was the one for the L78 application.

I believe that the P/S pump single groove pulley from an L79 is a 3834720, that page in my AIM is pretty bad, and that may fit the L76 application using the inner groove on the crankshaft and water pump pulleys.

The part number 3834720 is available on eBay, not cheap, but discontinued through GM. Or an aftermarket stamped steel CP38810 from Classic Performance Products, and or Summit.

Thats the current status, I haven't ordered either one yet.

Thank you again,
George

[Joe L.]

Re: L76 Pulleys for Power steering

Joe,
I looked at the pulleys again this morning, did a little research, and it appears that the 3995641, is a deep groove water pump pulley and was used in some 64-65 SHP engines. Sorry, it looked like a shallow groove with my worn out eyes last night.

I have further been able to identify that the P/S pump pulley from Borgeson is a part number 3878245, which was the one for the L78 application.

I believe that the P/S pump single groove pulley from an L79 is a 3834720, that page in my AIM is pretty bad, and that may fit the L76 application using the inner groove on the crankshaft and water pump pulleys.

The part number 3834720 is available on eBay, not cheap, but discontinued through GM. Or an aftermarket stamped steel CP38810 from Classic Performance Products, and or Summit.

Thats the current status, I haven't ordered either one yet.

Thank you again,
George

George-------

The GM #3995641 could not have been originally used on any 1964-65 application. That part number did not even exist until about 1971.

I believe the 3834720 is the correct pulley. I do not know if the aftermarket pulleys you mention will work. The pulley must be a "drop-down" type pulley to align with the water pump and crank pulley grooves. A "pancake" style pulley will not work.

[George C.]

Re: L76 Pulleys for Power steering

George-------

The GM #3995641 could not have been originally used on any 1964-65 application. That part number did not even exist until about 1971.

I believe the 3834720 is the correct pulley. I do not know if the aftermarket pulleys you mention will work. The pulley must be a "drop-down" type pulley to align with the water pump and crank pulley grooves. A "pancake" style pulley will not work.

Joe,
Thanks again for your continued support, and I appreciate the information on that 3995641. For now I will keep that pulley as it lines up perfectly with my 2 groove crank shaft pulley part number 3858533 which shows correct in the AIM, for my L76 motor.

Thanks also for confirmation on the 3834720 power steering pulley, I have a search setup and will buy an original for a long term solution. In the interim, I have ordered the cheap aftermarket CP38810.

I have also pasted the link to this part below for your viewing pleasure:

https://www.summitracing.com/parts/clp-cp38810

My primary reason for ordering this, is to drive the car this weekend, and I want to do a final update on this and the 3834720 so no one has to go through this again, if they choose to install the Borgeson Kit.


Thanks as always,
George

[Gene T.]

Re: L76 Pulleys for Power steering

Just throwing in my 2 cents worth; the '65 with the L76 did not have as an option Power Steering. I am aware of your desire to add the luxury.

[George C.]

Re: L76 Pulleys for Power steering

Gene,
Thanks for the $.02.

I guess if this was easy anybody could do it.

Updates to follow.

George

[Paul A.]

Re: L76 Pulleys for Power steering

Hi George,
I am reading this posting because I also installed a Borgeson P/S setup on my 64, the problem I have is that the pump and box get very hot. First I thought that because the box was close to the exhaust manifold, so I wrapped the box with an insulation pad, but the pump still gets very hot. Now I'm thinking its not the exhaust causing the problem. I'm now thinking of installing an inline p/s cooler. Let me know your thoughts and if you want to know what I used for pulleys I can get the part #'s for you. Thanks, Paul

[Joe L.]

Re: L76 Pulleys for Power steering

Hi George,
I am reading this posting because I also installed a Borgeson P/S setup on my 64, the problem I have is that the pump and box get very hot. First I thought that because the box was close to the exhaust manifold, so I wrapped the box with an insulation pad, but the pump still gets very hot. Now I'm thinking its not the exhaust causing the problem. I'm now thinking of installing an inline p/s cooler. Let me know your thoughts and if you want to know what I used for pulleys I can get the part #'s for you. Thanks, Paul

Paul------

Did you install a Borgeson system that's essentially the same as the stock system originally used on 1963-82 Corvettes or some other type of system?

[George C.]

Re: L76 Pulleys for Power steering

Hi George,
I am reading this posting because I also installed a Borgeson P/S setup on my 64, the problem I have is that the pump and box get very hot. First I thought that because the box was close to the exhaust manifold, so I wrapped the box with an insulation pad, but the pump still gets very hot. Now I'm thinking its not the exhaust causing the problem. I'm now thinking of installing an inline p/s cooler. Let me know your thoughts and if you want to know what I used for pulleys I can get the part #'s for you. Thanks, Paul

Paul,
Hi, I have not had any heat issues that I am aware of. I have only put about 100 miles on the car, including one 65 mile cruise. I was checking things out under the hood a couple of times during that 65 mile run, including checking the P/S fluid and did not have any excessive heat.

What diameter pulley do you have on the P/S pump, is it turning to fast? I will keep an eye on mine and let you know if it seems to be getting hot.

If you can send me your pulley numbers that would be great, right now I am running the pump on the outer groove of the damper, and the water pump. It requires a very long belt, and is working ok, but I do plan to change the alternator pulley, and run the P/S pump on the inside groove.

George

[Paul A.]

Re: L76 Pulleys for Power steering

Joe,
It is a Borgeson conversion power box system.

[Paul A.]

Re: L76 Pulleys for Power steering

George,
I did change the pump pulley from 6" to 5.5" because the 6" was to close to the frame. I have seperate belts for alt. & p/s with a 2 groove water pump pulley that I got on ebay. I will get the pulley #'s and send them to you with a photo if I can. Yesterday I installed a cooler on the p/s return line and will try it out today.