Calling all distributor experts here
11-10-2011, 10:31 AM
#1
3rd Gear Member
Thread Starter
Join Date: Feb 2008
Location: Nebraska
Posts: 794
Calling all distributor experts here
Long story short, my engine lost oil pressure a month back so I pulled it all apart and found a spun rod bearing. I ended up installing a new crank, bearings, etc. and reinstalled. In the process I installed a comp cams xe268h cam with some performance heads. I fired it up last night with no problems but saw I wasn't getting oil pressure. I know I do not have a faulty gauge either as I cut the tops off some old valve covers so I could see the rockers and there is no oil flow coming to the heads. Now this is the confusing part....... When I prime the oil pump with a drill I get great pressure and the oil flows up to the heads. After I ran the car and saw no pressure I shut it down and primed the engine with my drill again and the oil came right up.
Here's the deal..... This is a 289 engine and I am running a Proform HEI distributor. This is the same distributor I have been running the last two years on this car. I can clearly see the oil pump shaft and it is in place and working as I get great oil pressure with the drill. I did not change the shaft so the length is the same as it was when I ran the HEI before I lost pressure. I have inspected the distributor and can't see anything wrong on the outside. When I turn the rotor on the top the shaft spins. And yes, I have installed the distributor so it sits flush with the block. The thing that concerns me is that before I installed the distributor the first time when I was turning the rotor to line up with the number 1 position the gear wasn't turning and it felt like the rotor was possibly binding. I installed it anyways and now after starting the engine up I can't get it to duplicate this problem. If I turn the rotor the gear spins. Does this sound like a distributor problem? The car will start and run fine though. I am at a lost cause here.
Here's the deal..... This is a 289 engine and I am running a Proform HEI distributor. This is the same distributor I have been running the last two years on this car. I can clearly see the oil pump shaft and it is in place and working as I get great oil pressure with the drill. I did not change the shaft so the length is the same as it was when I ran the HEI before I lost pressure. I have inspected the distributor and can't see anything wrong on the outside. When I turn the rotor on the top the shaft spins. And yes, I have installed the distributor so it sits flush with the block. The thing that concerns me is that before I installed the distributor the first time when I was turning the rotor to line up with the number 1 position the gear wasn't turning and it felt like the rotor was possibly binding. I installed it anyways and now after starting the engine up I can't get it to duplicate this problem. If I turn the rotor the gear spins. Does this sound like a distributor problem? The car will start and run fine though. I am at a lost cause here.
11-10-2011, 10:53 AM
#3
3rd Gear Member
Thread Starter
Join Date: Feb 2008
Location: Nebraska
Posts: 794
Yeah, I checked the shaft for the oil pump before I installed it and it looked good. It also can't be stripped as I can prime the pump with a drill and oil flows up to the heads right away.
I also checked the bottom of the distributor to see if possibly the shaft was stripped on it but it looks good when I eye it with a light. I also took another hex head tool the same size of the oil pump shaft and stuck it in there and turned and there was no slippage.
I also checked the bottom of the distributor to see if possibly the shaft was stripped on it but it looks good when I eye it with a light. I also took another hex head tool the same size of the oil pump shaft and stuck it in there and turned and there was no slippage.
11-10-2011, 08:39 PM
#6
2nd Gear Member
Join Date: Oct 2011
Location: AL
Posts: 446
almost seems like the cam gear that drives the distributor is stripped. However the engine wouldn't start if this was the case.
It's wierd. The oil pump is locked into the distributor fine if you can prime it with a drill on the distributor shaft. But it doesn't pump oil on the engine's own power? If there's nothing wrong with the drive gear then I'm at a loss as well.
It's wierd. The oil pump is locked into the distributor fine if you can prime it with a drill on the distributor shaft. But it doesn't pump oil on the engine's own power? If there's nothing wrong with the drive gear then I'm at a loss as well.
11-10-2011, 09:17 PM
#7
6th Gear Member
Join Date: Jan 2007
Location: AR
Posts: 5,469
almost seems like the cam gear that drives the distributor is stripped. However the engine wouldn't start if this was the case.
It's wierd. The oil pump is locked into the distributor fine if you can prime it with a drill on the distributor shaft. But it doesn't pump oil on the engine's own power? If there's nothing wrong with the drive gear then I'm at a loss as well.
It's wierd. The oil pump is locked into the distributor fine if you can prime it with a drill on the distributor shaft. But it doesn't pump oil on the engine's own power? If there's nothing wrong with the drive gear then I'm at a loss as well.
My guess is that the distributor is not engaging the oil pump drive shaft, might be that the shaft is marginally short and/or the hex is worn away in the distributor.
The issue IS going to be with the shaft, the distributor, or the pump itself. (or some combination of the three)
Also, since you had an oil pressure issue that destroyed your previous engine, I think the same issue remains. You might want to start by replacing that ProComp distributor with say a cheap reman stocker for a test run.
Last edited by JMD; 11-10-2011 at 09:57 PM.
11-11-2011, 07:18 AM
#9
2nd Gear Member
Join Date: Jun 2005
Location:
Posts: 290
My guess is that the distributor is not engaging the oil pump drive shaft, might be that the shaft is marginally short and/or the hex is worn away in the distributor.
Also, since you had an oil pressure issue that destroyed your previous engine, I think the same issue remains. You might want to start by replacing that ProComp distributor with say a cheap reman stocker for a test run.
Also, since you had an oil pressure issue that destroyed your previous engine, I think the same issue remains. You might want to start by replacing that ProComp distributor with say a cheap reman stocker for a test run.
11-11-2011, 09:20 AM
#10
3rd Gear Member
Thread Starter
Join Date: Feb 2008
Location: Nebraska
Posts: 794
UPDATE:
Upon further inspectoin of the distributor drive gear I see that it looks slightly rounded off or worn. When I put a hex tool in there I can't get it to slip but then again I'm not putting the same kind of torque on it that the engine is. I have the stock distributor yet and even compared the drive gears on both and can clearly see the HEI is rounded compared to the good stock one.
Now the very frustrating part is that I have only put 3,000 miles on this car since installing the HEI. I have already put in a phone call to Summit Racing, where I purchased it, and was given the phone number to the manufacturer. They claim they have never heard of this happening and want me to mail it in to them for inspection so I figure I will do this since I have nothing to loose. Either way, I will never put a Proform HEI on anything I own again.
Upon further inspectoin of the distributor drive gear I see that it looks slightly rounded off or worn. When I put a hex tool in there I can't get it to slip but then again I'm not putting the same kind of torque on it that the engine is. I have the stock distributor yet and even compared the drive gears on both and can clearly see the HEI is rounded compared to the good stock one.
Now the very frustrating part is that I have only put 3,000 miles on this car since installing the HEI. I have already put in a phone call to Summit Racing, where I purchased it, and was given the phone number to the manufacturer. They claim they have never heard of this happening and want me to mail it in to them for inspection so I figure I will do this since I have nothing to loose. Either way, I will never put a Proform HEI on anything I own again.