calling all engine builders
 

ok so i have a big problem. I just finished rebuilding my 94' gen 5 502. Now when i start the engine there is no oil pressure!!!!! So I primed the system with a drill and got 60psi oil pressure so im thinking im golden, well once i put the distributor back in and fired it up still no oil pressure. So i preceded to keep priming the oil system multiple times with no sucess. Ok so i pretty much used all the stock parts including the oil pump which worked fine before the rebuild. The only thing I changed was the cam and i converted it to a roller cam. So here are some thoughts maybe distributor is to long or short? but it appears the same. Maybe oil pan is bent and restricting the oil flow to the screen of the oil pump? Has anybody ever had this problem or have any ideas? Im wondering if i need a gen 6 distrubutor? is there any difference bewteen gen 6 or gen 5 distributor? Please help and sorry for the long post

i did the exact same thing... i have a gen 5 502 and i installed a gen 6 cam. there was no difference besides the step nose where the timing gear is installed. i used the gm performance bracket (no cam button) i upgraded my oil pump to a blueprinted melling. i used the same distributor that comes with the mercruiser t-bolt setup. everything works fine on my end though. is the gear ok on the distributor? and is the slot in the distributor ok? also what came with my new melling was new plastic retainers that hold the extension shaft on the pump and keep it square. mabye the pump shaft is going off to one side of the distributor during installation. i know every time i remove the distributor i have to play a little to get the oil pump drive in line with where the distributor will sit when the gears are meshed. unless you have some very weird electrical problem i would remove the sender and put a manual gauge in that oil port and make very sure it is making oil pressure both with a drill and engine running. best of luck and keep us posted!

well i put a manual gauge on and i get oil pressure with drill primer and then none with the distributor in so i dont know what else. the gear end is fine ...... anybody else i need help

Somehow the distributor shaft is not making contact with the slot on the oil pump.

You should be able to feel the dist shaft drop into the slot.

If the engine is firing then the distributor gear is making contact with the cam gear.

Is this a new intake manifold??? New distributor gear???????

Push some grease into the bottom of the dist shaft gear and then reinsert the distributor. The grease should get pushed out if the shaft is going into the slot. If it doesn't, remove the distributor gasket and try again.

Does your distributor have a slip collar? Do you have someone around who can give it one? It's quite easy, grind off the collar as it sits, machine a split ring that goes around the shaft with a screw to fix in place and drop it in without a gasket, then drop the slip collar down and secure it. When you put the gasket on you'll be good to go!

Or you could buy an MSD Pro Billet with the slip collar.

Good Luck mate!

MSD offers the slip collar seperate.. Machine off the flange and slide on a collar.. then adust the height.

You should be able to feel the dist drop on the oil pump shaft. Can you see the slot in the top of the shaft down in the hole? Line it up and see if you can feel the dist shaft slide into it. The dist height does two things, besides alinging the cam gear and dist gear. It connects to the oil pump shaft (do you have the correct one?) and it blocks the ports in the block to direct oil to the lifters.
If you can pump oil with the drill, then you should be able to do it with the dist. It has to be the connection to the oil pump shaft.. To spin up an oil pump. I machined the teeth off a chevy dist and slide it in. That gives me the assurance that the dist is connected to the oil pump shaft with a stock height dist.. I also welded a 3/8" socket to the top of the shaft so I can connect the drill to it and spin it for psi checks..

Keep looking, it is something simple if you get 0 psi.. Step back and look at the simple things..

good luck and keep us posted.
Dick

if it all worked before, should now as well, those slip collar dist are so you can use one dist for either a std or tall deck, there is no diffence in the gen IV, V, VI 's are you sure the dist dropa all the way down into the machined portion of the intake, not just in the cam gear ? once you get it spin the engine over while hold the dist down should drop down another 1/4 inch into the oil pump, if thats not it the relief valve in the oil pump may be stuck open and no pressure..had that happen..Rob

I had a similar problem GenV block GenVI cam, but my problem was when I was priming my block I could not get oil through the 1 and 2 lifter gallies. The problem was that the primer was just a hair short and was bleeding oil between the distributor and the block. I could see that oil was circulating but not enough pressure to make it to the furthest lifters. I just was not seating the primer deep enough and had to adjust the slip collar. It worked fine on my first engine, but not on the second.

Not to hijack this thread, but how tight should the fit be between the distributor boss and the block. On both my Gen VI blocks the distributor seems like a sloppy fit (I can push the top of the distributor around quit a bit with the clamp loose). I think I am bleeding alot of oil pressure because of the fit. Should it bleed alot by design, maybe to lube the dist. gear? I can change the oil pressure on the gauge by loosening the dist. clamp and moving the dist. sideways a little.

Read this thread all will be revealed:ernaehrung004:


http://www.offshoreonly.com/forums/g...-hardware.html

If there is oil pressure with a drill and priming tool but none with the distributer, then it is the distributer . It's unlikely that clearence between the base of the distributer and the block would lead to no oil pressure at all. For some reason the dist. seems to be too short.

Wobble - maybe I missed it, but I didn't see anything on the tolerance or fit the distributor should have when it passes through the block (oil galley). Still wonder if it should fit tightly, or if there is some clearance by design that bleads off oil to lube the dist. gear. Even running the oil pump with the correct priming tool, alot of oil (and pressure?) is seems to be bled at that point.

If your pan is bent or dented and you dont have at least 3/8 of an inch clearance when you start the engine it is sucking/starving for oil. I had this problem on a 460 ford once. The primer turns slow enough to replenish oil under the pick up but can't with the higher rpms after start up.

thanks for the help everyone, but yes the dist. goes all the way in and is flush with the block, also it feels like the shaft is going into the bottom of the dist. I will try and use that grease trick........ i put in a aftermarket procomp dist and still no pressure. the cam gear is good as well. im stumped..... if the relief valve is open in the oil pump is there anyway to fix that? thx again

Is the drill spinning clockwise when priming?

I would measure the distance from the oil pump drive shaft to the intake surface where the dist clamps and compare that to the distributor dimensions.

Ok so now we prime it with a drill and turn over the motor and the oil pressure goes down to zero, now what ?

oil pickup might be too close to the pan, allowing pressure to build at low drill speeds but not at engine speeds.

If you pull distributor out move 1 tooth either way will it still go back down all the way flush on intake

Make sure you dont have a small block oil pump shaft in it.I put in a motor for a customer one time that he bought from some one and it had the wrong shaft in it

Tell us about your roller cam conversion kit or pieces?
I have seen these type of conversions go wrong with the lifter center oil feed recessess dropping below or above the lifter bores in the block and dropping all the oil pressure because the lifters are not sealing in the bores top and bottom. Usually it comes from aftermarket cams with too small of base circles or from using the incorrect lifter with the cam or conversion kit. Just a thought here to add to the other points already brought up about distributor to oil pump shaft fitment and oil pump pickup incorrect height.
Also did you refit or weld the pickup tube on the pump cover with a full weld as I have seen this overheat the pump cover and freeze the oil pressure relief piston in its bore locked open, which will dump to much oil, however you're getting good oil pressure when priming the pump which does not indicate the relief valve being locked open.

Hope we can help find your Gremlin

Best Regards,
Ray @ Raylar

well i put a new oil pump in and used a hammer to pound out the bottom of the oil pan but i couldnt really tell if it was bent but didnt want to take a chance. I had to pull the motor and i was pissed so didnt want to take a chance. But before we put the motor back in we turned over the motor with the distributor in and it was pumping oil up thur the pushrods. with the valve covers off. then i put the motor back in and turned it over and got oil pressure so i think im in the clear. ill let you know tommorow when i start it up and set the timing. What a pain in the a** i hope it works

Hope that solves your problems. However, you really should measure the oil pan depth with a straight edge and ruler and set your pick up accordingly. I am curious, how did you crank the engine over on a stand, with the distributor in, and get oil through the push rods? I have enough trouble getting oil up with a primer I made from an old distributor.

So how did it go?

well i have been at work for the past 2 days and wont be home till wednesday morning, but my dad said he will probably go home after work and set the timing and start her up, so i will keep you posted