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Has anyone ever used a power steering pump from a c4 on a c3? My Saginaw has been rebuilt so many times it is time to replace it. I am putting a L98 c4 engine in my car and it came with the c4 P/S pump. Just not sure if the pressures are that much different.
I wouldn't worry about the pressure...worst thing it'll do is find a weak seal..I'd go with it because it's a whole lot easier and cleaner doing then swapping the c3 on there
I remember 12 years ago when doing the L98 serp install....someone saying to keep the original valving, just replace all those brass parts in the line out spot....they swap over....so I did, and it was/has been fine....since then I put in a rack, but lost track of the original C4 pump parts/valves.....so I running the rack with C3 pump valves in a C4 pump for over 5 years now....no sweat....HB unit too boot, no problem...
Frankly, I don't think there is a whole hell of lotta differance anyway....
interesting.......what has to change? brackets, hoses, cylinder?
The engine I am putting in has all the correct brackets and all. so I am not too worried about it. Sounds like from the other response that it not a big deal, and what is the worst thing that happens I don't have power steering for a while until I figure something else out.
I remember 12 years ago when doing the L98 serp install....someone saying to keep the original valving, just replace all those brass parts in the line out spot....they swap over....so I did, and it was/has been fine....since then I put in a rack, but lost track of the original C4 pump parts/valves.....so I running the rack with C3 pump valves in a C4 pump for over 5 years now....no sweat....HB unit too boot, no problem...
Frankly, I don't think there is a whole hell of lotta differance anyway....
I think this is the answer I wanted, I am going to try it and if there are problems I will figure something else out. Thanks!
I wouldn't worry about the pressure...worst thing it'll do is find a weak seal..I'd go with it because it's a whole lot easier and cleaner doing then swapping the c3 on there
I agree, cleaner and less messy. Now what to do with he smog pump?
I agree, cleaner and less messy. Now what to do with he smog pump?
for airpump dumping, you need go to Breathless Performance .com....Ernie still makes his near first product....the airpump eliminator kit.....expensive....but the only alternative I find is gutting the airpump and using it as an idler....
typical L98 serp setups have to have a idler there, no way cheep around it....
I just wanted to add a couple of pictures to this thread. I am in the process of putting a 91 L98 in a 79 C3. I took advice from this thread and a few more. I pulled the power steering line-out valving from the 79 and put it in the 91 pump, so I could use the C3's factory power steering. It fit perfectly. Interestingly enough the C4 power steering pump didn't have any valving inside. (I bought the engine from a guy who had already swapped it into a kit car so he may have gutted it to make it work for his application). The silver valve and fitting on the left are from the 79 and the brass fitting is from the 91. No valve from the 91. Nearly identical from the outside, threads are the same, pressure line fitting is the same threads too. The outside nut for the fittings are 1 1/16 inches and 21 MM respectively. If you look carefully you will see that the port size in the left one (79) is a little bigger than the other (91) The fitting on the left has an orifice (for lack of better word) inside it, that forms the flare lip for the pressure line. The other doesn't have it.
I hope these pics help someone, it would have been nice for me to have had a few months ago.
* disclaimer: I haven't started the engine yet, so this is all theory at this point, however I don't anticipate any issues as I have read of many others doing the same thing with good results.
Mr. Jet I have put an L98 into a 78 C3. The PS was the biggest issue ( next to the computer) and after doing some research and using this forum, I came across some information about the pressures. I can't recall the numbers but the C4 pump was set up for a rack & pinion, way higher pressures than our cars will take. I used a Borgeson 899001 pressure reduction kit which just went into the valve on the c4 pump. I can get you more specific details if you'd like. The biggest issues I had were with some of the lines, especially one of the hard lines and I had to ADAPT a fitting onto the hard line to match up with the pump pressure line. Ended up welding it since most adapters won't hold that kind of pressure. I can look for more details if you want. The other problem was the remote resevoir. My L98 is from an 86 c4 and the remote mounted on down near the radiator. Other sperpentine setups have a pump with the resevoir attached. I believe your 91 might be one of those. When you are ready to start it up search for initial starting and PS pumps. You will need to bleed the system. If you'd like any other EXPERIENCES I have had with my project that mgiht relate to yours, just PM me. Good luck.
Has anyone ever used a power steering pump from a c4 on a c3? My Saginaw has been rebuilt so many times it is time to replace it. I am putting a L98 c4 engine in my car and it came with the c4 P/S pump. Just not sure if the pressures are that much different.
thanks
Two factors will effect what needs to be done.
1. pressure
2. flow.
The stock steering likes a max pressure around 900-1000 PSI and a flow around 2-3 gpm
c4 power steering pump on a c3
