I found a NOS distributor complete with a new Vacuum Advance for my 250 I6. The chiltons manual says a to remove and replace a distributor I just need to mark the distributor location with respect to the engine and also mark the rotor location to the distributor before removal. Will this also work with changing the distributor if I set the new one to the same spots then just reset the timing if needed? I don't want to go through the trouble of setting the engine at TDC compression stroke.
Trying to shortcut a step to save time has always cost me more time and headache in the end! It really doesn't take that long to line it up at TDC. That said, you are on the right track and might get away with it if your marks are perfect. Good luck!
Thanks Rick, your probably right, better to have things lined up first. This is a new procedure to me. Here is what I saw on youtube. Pull all 6 spark plugs so engine can rotate easier. Put a compression gage in #1 spark plug hole to make sure its coming up on the compression stroke. Put a pencil or dowel rod in the #1 hole to see when cylinder is nearing TDC then fine tune with the timing mark. Does this all sound right? Also, how hard is it to turn the motor over with spark plugs removed and car in neutral? Would I need a second person? Initially I thought if I messed up doing this I could cause severe engine damage but it sounds like the worst that could happen is it just would not start/run.
If original position of dist is known, there is no reason chase after TDC. If unknown, TDC on compression stroke is the logical start point. Could just as easily use TDC on exhaust stroke & point rotor at #4(or #6 if V8). Carefully mark dist setting, note exactly where vacuum canister in pointing, take a picture. Mark location on dist housing where rotor points. Only one correct location, if off a tooth on reinstall, will be at least the width of rotor contact from mark. Pull & try again. Should run with no issue, always check timing. Eons ago I marked location of dist on my 428, used chisel to make light mark on both intake & dist(FE dist insert through intake). Also a mark on dist housing for correct location when engine is at TDC.
Ok Thank you. I figured even with transposing my location mark onto the new dist. I should be able to get it close enough to start up then just retime it. I found a nice deal on this complete new old stock distributor. I want to go to with a restored original look engine compartment.
another $ .02 : Important - as distributor is removed the 5/16 hex drive from oil pump (@ 2" long) will either stay in bottom of dist. or stay down in the engine's oil pump. It is not attached to either and can easily fall into the oil pan if dislodged !. Distrib' swap: > turn engine with fan to near balancer TDC timing mark with rotor pointing away from block (towards #1 as marked on dist cap or #1 wire ) Remove dist. cap out of way. > note approximate position of the dist related to block, remove dist lock clamp and gently pull up on dist. - * * as dist comes up, the rotor will follow drive gear and rotate a bit, these are positions new dist. and rotor need to be in to re-install. Hex drive must be engaged in oil pump for re-install, and may have to 'jiggle' rotor to engage hex shaft as dist. is inserted. > button up cap, start engine and adjust timing to your preference. IF the engine spits and back fires it's off time - line up balancer TDC and repeat installation more carefully until dist. is close to original distrib position .... IF the oil pump hex drive should ever inadvertently falls into oil pan - it can easily be fished out by removing fuel pump for access to using a stick magnet into pan - (ask me how I know... ) hav efun
If I were going to line up TDC I would just line up the timing tab and make sure the rotor is pointing at #1 on the distributor, that will get you close enough.
Thanks for that advice on how to retrieve the oil pump shaft!!!! That sounds exactly like something that would happen to me!
That's a good point (no pun intended) if the timing mark is aligned and the rotor is pointed at #1 its gotta be at the compression stroke, right?
The good thing is that the 250 is pretty much bulletproof and if you do go out a tooth or so, you shouldn't do any real damage (especially if you don't run it long) like an interference engine. Personally, I'd go with the advice to take the extra precautions then just lining up the distributor. Always better safe than sorry and the extra work setting up the engine may just save you aggravation and more time on the back end.
A tooth off on the distributor won't hurt anything, just causes a few challenges. Reached a point where I would just move wires when I put it in 180 out (happened more often than I care to admit). It really doesn't care about orientation of the housing and shaft so long as the rotor points to the correct wire when that cylinder needs the spark. The cam however, it's very finicky about which teeth line up!
Makes no difference if engine is interference, distributor timing has zero effect. Problem occurs when/if valve timing shifts due to slipped/broken belt or chain.
Very true but the point being that you still have to be careful with an interference engine regarding timing period.
Makes no difference if engine is interference, distributor timing has zero effect. Problem occurs when/if valve timing shifts due to slipped/broken belt or chain. and: ... if the dist. gear is off it will only shift the position of the dist. housing but may make the vac. diaphragm interfere with block.