View Full Version : Big block vs. small block power steering pump
kz1000ltd Dec 29th, 00, 12:48 PM OK, I'm just about ready to start working on the power steering conversion, I was told today that the small block and big block pumps are different, can someone explain to me what the differences are, and how I can tell what the pump I have is off of? I think it has something to do with how the lines come off of it, for clearance reasons, but want to know for sure before I start tearing into it.....thanks. KZ
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John D. Smith
69' SS/396
www.geocities.com/kz1000ltd (http://www.geocities.com/kz1000ltd)
William Dec 29th, 00, 01:42 PM The pump is the same; it is the return nipple off the reservoir that differs. On a bb it has 2 90º bends. The first is down, then left. The reservoir may be 69 only.
I would bet a radiator shop could install a new nipple on a sb reservoir.
craggar Dec 30th, 00, 05:18 AM The only thing I changed was the bracket.
awsm502 Dec 30th, 00, 07:14 AM John, William is right in that the two pumps are the same, so if you have a good small block pump, all you need is the BB reservoir or "can". The information below I know is correct for a '69, I do not know if it translates to '67s or '68s.
The return line nipple on the bb pump comes off the bottom of the can, has a 90 deg bend, and when mounted on the engine points toward the oil pan. This is so the line clears the exhaust manifold, and is routed under the engine alongside the motor mount.
The small block pump has the nipple comming off the back of the pump. This places the line very close to the exhaust manifold. When I first got my car, someone replaced the pump/can with a smallblock unit, and the retern nipple was bent in order to clear the manifold.
Hope this helps. Also, the assembly manuals shows some pretty good shots of the difference between the two installations.
Good luck, BB cans can sometimes be hard to find.
Keith
'69 RS/SS 396 (now a 502)
kz1000ltd Dec 30th, 00, 01:49 PM Well, the initial attempt wasn't too successful. I sprung for an aftermarket set of big block brackets, and the one that goes on the back of the pump did not seem to fit correctly. Since I couldn't even figure out how it was going to bolt up, I didn't even attept to pull the headers off, or pull the manual gearbox off. I think I'm going to have to splurge for the new big block pump also. Oh well, it was worth a shot. Anyone need a good used small block pump? Also, does anyone have a good photo of the big block bracket setup? I have a feeling I may have to spring for the assembly manual also. 1st quarter score: Power steering conversion - 7, KZ - 0........I figure if the subframe bushings took me 3 weeks, this conversion will take at least a month. Oh well, I will keep on trying...... http://www.camaros.net/forum/smile.gif
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John D. Smith
69' SS/396
www.geocities.com/kz1000ltd (http://www.geocities.com/kz1000ltd)
[This message has been edited by kz1000ltd (edited 12-30-2000).]
lnjstreetrods Dec 30th, 00, 09:41 PM John,
I have some BB ps parts, I will try to look and see what all I have and let you know.
Larry
kz1000ltd Dec 31st, 00, 04:29 AM Lying in bed last night, I had a brainstorm. The bracket that connects to the side of the head seemed to be about an inch off, maybe this is because I have headers instead of an exhaust manifold? Hmmmmmmm.......interesting. Also, even if this bracket had lined up, it has 7/16 threads into it, because the header bolt fit right into it. But if has threads in it, how would the bolt thread through the bracket, and then the head? I'm confused, I bet I'm going to have to jury rig something to accomodate the headers. Anyone else ever run into this? Let me know what you have Larry, I appreciate it.........KZ
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John D. Smith
69' SS/396
www.geocities.com/kz1000ltd (http://www.geocities.com/kz1000ltd)
lnjstreetrods Dec 31st, 00, 10:30 AM John,
I looked at the brackets I have, and I wanted to be sure my memory served me well before I began to make statments, and it is the way I thought.
As has already been stated the pump its self fits, BB, or SB, it's the brackets that are different, and the cannister.The ex manifold don't come into play on the BB bracket.The bracket I have bolts to the 2 7/16 holes in the lower front of the block, and there is a tab that takes a bolt around the side of the block to brace it, part of the same bracket.
The other bracket bolts into the front, top 2 holes of the pump, W/ 3/8's bolts. This is the adjuster bracket, and has a 1/2 bolt that screws into the water pump, and is slotted so you can adjust the belt.
It will be best to have the can for the BB because of the return nipple out of it is different.
Hope this helps. If you need more info email me.
Larry
awsm502 Dec 31st, 00, 10:40 AM John,
The BB setup comprises of three brackets. The pump is "craddled" in one that swings off the water pump. One small bracket bolts to the side of the block, and to the first monting hole of the D.S. exhaust manifold. Yes, for headers you will need about a half inch spacer to get it to sit right. The third bracket bolts to the front of the pump, and has a long slot in it for the adjustment. The bolt that is used to adjust the system goes through the long slot, and then into the threaded hole in the small bracket that was bolted to the exhaust manifold. I think you have this small bracket in the wrong orientation if you are trying to put a bolt through the threaded hole, then into the block.
The assembly manual is a must have. It is a wealth of information, especially if you are a do-it-yourselfer.
I hope you have also taken into account that the pittman arm, Idler arm, and spindle legs are different lengths on a power vs. manual steer car. There is a ton of info on this in the suspension folder of this bbs.
I have a digital camera at work, and I will take some photo's of the installation on my car and e-mail them to you. That is, unless someone beats me too it.
Keith
'69 RS/SS 502
William Dec 31st, 00, 11:25 AM Steering linkage components are different for a fast-ratio power steering car. Standard power steering was not fast ratio. If the conversion is being done on a genuine manual-steering SS, the car is probably not fast ratio. An SS ordered with ps would be fast ratio. If the power box to be used has a pitman arm that is about 5.2" c-c everything will bolt up just fine. If the box has the 5.75" c-c pitman arm, it will have to be replaced with a 5.2" arm or all the components mentioned will have to be changed.
kz1000ltd Dec 31st, 00, 05:31 PM awsm502, that would be great. I have an assembly manual on the way, but it might take a week or so to get it. Email it to me when you get a chance......Thanks for the help.....KZ
pdq67 Dec 31st, 00, 06:19 PM KZ,
Don't feel bad. Did a valve job on my brother in laws '66 Buick Special years ago for a 1/2" torque wrench.
Made one mistake, while I was pulling the pass. side head, he was undoing the P/S bracktry. After about three, maybe for days to get the heads done, He forgot how the bracketry went on. Luckily there was another '66 Buick in town and I asked the guy if we could have a look-see. Worked great, He, He!! Happy New Year. pdq67
PS, If the P/S bracketry gets to be too big a hassle ($$$) call Allen Groves up and get the stuff from them. They got good stuff. IMHO.
Kurt S Jan 2nd, 01, 12:43 PM There is one other SB to BB difference.
I believe the reservior neck tilts forward more on the BB pump to clear the AC brackets.
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Kurt S.
www.camaros.org (http://www.camaros.org)
gheatly Jan 2nd, 01, 12:55 PM KZ, you hit the nail on the head. The stock bracket does not fit with headers. There is a spacer you need to go between the header flange and the bracket. It is basically a small piece of tubing cut to length and it takes up that inch or so you mentioned. Small blocks need the same spacer. Oh yeah, you will also need a longer bolt.
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Pearl blue & white 69 Camaro with supercharged 350, Tremec TKO, and 3.73 12-bolt
See my website updated 12/17/00 at:
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