zigzag240

Makes sense...but I guess what I'm really asking is on a F54 is there a "correct" idle timing setting that calculates out to 34-36 when revved above 2500? 19 would ping pretty heavily on an engine asking for 8btd stock I would think. My area is very surburban and it's tough to do 'test and tune', I kinda would like to set to the right spot once and drive. I appreciate any input.

My car is a F54 with '82 "8.5 degree" dizzy and E12-80. I've searched the forum and understand the concepts, but I'm still unclear how to adjust my distributor timing to reach a max of 34-36 degrees. Using an adjustable timing gun: - set static timing at idle to 10. - dial the gun to 26, rev the engine when the dizzy advances fully the timing mark should point at 0tdc. That means 36 degrees total? Is it that simple?

You guys hit it right on the head...it was a bad diff mount. Just above the diff I could see the edge of the handbrake mechanism was scored from the bolt flange of the driveshaft where it rubbed it...that was the noise. The mount looked ok, but a screwdriver slipped in and twisted would really distort the rubber. A buddy had a new one and I put it in this afternoon. Solid as a rock now...burns off the line now without a hiccup. So don't always listen for a clunk...

I held my camera under and shot a few images, the driveshaft joint and front diff flange look fine. I suspect it's the front diff mount...couldn't be much else, guess I never heard a truly broken mount before...tomorow will tell.

I have a '71 240 with L28, 4.11 R200 and '82 5-speed I've been running for years with no problems, autocrosses, fast street, etc. Today I tried a fast launch from idle, and as soon as the clutch was let out I heard a metallic ratcheting sound from under the rear of the center console...exactly like the sound a power drill makes when the adjustable clutch slips...but very loud. That spot is over the front of the differential but this was totally different than the common Z rear-clunk. I only happens at launch...not in any other gear or speed. My possible guesses: front diff flange loose, front diff bearing bad, rear driveshaft u-joint. Maybe even the front diff mount...but in the 27 years I've been driving Z's I've never ever heard this sound. I'll drink lots of beer tonight and worry, and will be going under the car tomorrow. Just wondering if this sound rings a bell for anyone else.....

I appeciate your checking for me. When I had my old driveshaft welded I remember it was a 1/2 inch or so too long or short but can't remember which. So if I know exactly where the front disc is positioned in the tailsghaft I can estimate the exact length of the new one.

Need help on this......I have a '71 240 with F54 and Nissan '83 BW T5 and R200. When I put the trans in a few years ago I had the T5 driveshaft shortened by a couple of inches to fit. Now I want to get a 'real' driveshaft fabricated to replace the old one which is getting shaky and I'm doing measurements to have one made. Here's my question: where the front yoke goes into the tail of the trans, it passes through a round "collar". And just in front of the u-joint is a fat ring that fits inside this collar. Can anyone tell me where exactly this ring is supposed to sit? It it supposed to be perfectly flush with the end of the collar, or sit inside a fraction of an inch? Anyone have a stock setup they can glance at for me? ----------l___________ ----------l

All the gaskets are fine, so I just changed the oil/filter and ran it a while, and shut down. When I unscrewed the new filter it began to really drip new oil, so the new filter appear to be filling ok now. The only thing I can think of is the filter's relief valve was leaking and allowed most of the oil to drain back into the block, and the filter looked empty. I'm using a turbo pump and it really seems to be putting out the presssure. My scare for the week, thanks for the tips. -B

I have a F54 with P90 and SUs that I spent several months rebuilding and dropped it in last week. I have 250 miles on the motor now it and it runs perfectly. Oil pressure is 15-65psi, compression is great, the engine is solid with no leaks or noises. Pulls hard and starts perfectly. Today I just gave it it's first oil change and found that oil filter was empty, and appeared to have only the oil I poured in to prime it (!) What could cause the oil to bypass the filter like this? The way the oil passages run I thought the oil had to pass through the oil filter first. Since I'm getting great oil pressure this one is really baffling me. Could it just me a bad oil filter?

I had been looking at the full wrap-around clamps, glad to hear people have had success with them. Thanks for the tips. -B

I decided to get rid of my rusty old 2 1/2" pipe on my 240/L28 and replace it with a new complete 6-1 header and 2 1/2" pipe setup from MSA. I don't really have access to a welder, so how durable/leaky is it to put the system on relying on just the pipe clamps to seal each joint? Magazines and muffler companies show everyone doing it, but it seems like that's asking for leaks down the road. Opinions?

Actually mine are ITM at .020" over, I mistyped ITC, my bad. I just spoke to a tech Winston at ITM, he was friendly but as you said no help...he said they didn't show any end gap specs for them. oh well... thats what makes rebuild so fun..

I just had my F54 block overbored by .020" for my summer project, I'm putting in some 86.5mm ITC pistons, chrome top rings. I have it back on the stand and I started trying to calculate the ring end gap because is didn't have the shop check it for me. But between the 'How to Modify...' book and the FSM I'm confused. My bore is now 86.5mm or 3.405 inches. Can some kind soul help me calculate the new, proper ring end gap for the top and second ring.....

Thanks for the perfect responses....guess I'll save this roller bearing for a swap meet in year 2016...

Yikes, I've been solid bushings for years but thought I would use one for my current rebuild. I didn't realize they were so fragile...roller bearings last for years in T5 transmissions, I wonder if peope aren't lubing them...?

A search didn't turn up anything on this one.... I'm installing a Nissan roller pilot bearing in the rear of my L28 crankshaft during my current rebuild. The bearing itself has a thicker outer race on one end compared to the other, (to drive it in?). When I slip in a clutch alignment tool it seems to have the same roller clearance in either direction though. So has anyone ever installed a roller pilot bearing and determined the proper direction to drive in?