When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Long story short. Rebuilt the top end of my 91 302. Heads were milled (not sure how much) remanned units from ebay. Rocker clearance checked out with no shimming required. Got everything together and took it for a test drive. Distributor seized up and sheared the distributor gear pin. Looked things over. Oil pump is NOT seized oil pump shaft is in tact and cam gear is fine. Stuck my stock dizzy in and there is NO play. Is it possible that I need to shim my distributor housing up to mesh properly? Wear on the new distributor gear is extremely deep. My thoughts are that since the heads were milled, the intake sits lower, hence making the distributor sit lower and put it in a bind. Please let me know your thoughts on this.
The distributor sits on the engine block so head milling has no effect on it. Is your distributor OEM or aftermarket? Did you install an aftermarket cam in the motor?
Stock cam. New sealed power oil pump (standard duty) and sealed power oil pump shaft. OEM distributor. Oil pump shaft is installed correctly. I'm at my wits end here.
I found the culprit. I had an old distributor lying around and shaved around 1/8" off the bottom of it. Boom. Perfect fit. Gears mesh perfectly and distributor sits flush with the block. There is also up and down movement which wasn't present before. Is it possible that the oil pump shaft stopper is sitting too high?
I would suspect that oil pump, no matter what you think of it now. Distributors are not known for seizing up like that. The keeper on the shaft slides, it's not going to cause the distributor to seize up. Now, if you had an aftermarket HD oilpump drive for an earlier application and tried to use in on that distributor, that will limit the distributor as far as sitting all the way down into the block. The EFI distributors had a longer shaft that required a different HD oil pump drive.
I would suspect that oil pump, no matter what you think of it now. Distributors are not known for seizing up like that. The keeper on the shaft slides, it's not going to cause the distributor to seize up. Now, if you had an aftermarket HD oilpump drive for an earlier application and tried to use in on that distributor, that will limit the distributor as far as sitting all the way down into the block. The EFI distributors had a longer shaft that required a different HD oil pump drive.
hmmm... Not what I wanted to hear. Any idea what i did wrong? I primed the oil pump before I installed it and primed it before I started the motor with a oil pump priming tool. I checked it again last night and the oil pump shaft still spins and is still engaged in the oil pump. I installed my new distributor, check all clearances with white lithium grease (perfect fit by the way) but the motor will NOT start. I have fuel, I have spark. Any other suggestions I could check?
I've seen brand new pumps seize before. Did you take it apart before installing it to verify it was clean before you used it ? As for the no start, not enough info there to say. Could be out of time would be my first guess. Maybe 180* off ?
Bringing this back up to the top. I verified that the oil pump isn't seized. I tore the motor down this morning. Removed upper intake and valve covers to see what's going on. No bent valves or push rods that I can see. The problem I found was when cyl. #1 intake valve is open, the harm. balancer TDC numbers aren't even CLOSE to lining up. Now, I have a brand new Cloyes timing set in there which was installed correctly. Is there any way a new chain set could skip a tooth or does anyone have any other suggestions on what to check?
There are two TDC's, neither of which the intake valve will be fully open. At the top of the exhaust stroke, the intake valve will just be about ready to open (depending on the cam profile and how it's installed) At the top of the compression stroke, both valves will be closed. Sometimes bent pushrods cannot be spotted until you remove them and roll them across a smooth surface. The timing marks on the set should align when the crank key is at 12 o'clock (this is a must) the cam dot can be either at 12 or 6 o'clock. The crank spins two revolutions for each revolution of the cam, in other words the cam spins at half the speed the crank does.
Well, my ******* wasn't checking the oil pump properly. I thought just because it still spun by hand it was still working. A friend suggested hooking a drill up to the priming tool and what do you know,it spins but extremely hard. No oil is getting up to the rockers either. So baddad, you were right all along. I feel like a moron. I'll get this thing changed out and hopefully started soon. Thank you all for your help.
The oil pump should spin with a lot of resistance, it's a positive displacement pump trying to force oil though many small passages. With the engine running, you should have 30-80 psi pressure in the system the pump is trying to force oil against. Once you start spinning the oil pump shaft, it will take a few minutes to get oil up and out of the pushrods. Even then it'll just ooze out of the rockers once it gets there. The rear rockers will be the last in line to show oil. I use a 1/2" drive drill to spin the oilpump drive, most 3/8" drive drills won't cut the mustard, there should be that much resistance once the oil starts moving.
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
