Ownallday

Thanks everyone for your feedback and knowledge. Was able to replace the timing chain and tensioner earlier today in about an hour. Happy to report the issue has been resolved and the tensioner is no longer crazy extended, safe to say the chain was just extremely stretched. Hopefully this week the car will be running again with a fresh new engine rebuild.

That looks about as similar to what I have now. That brings a lot of extra relief to me haha. Thanks for sharing. Will share pictures tomorrow of my results.

I suppose I can do without it. Suppose it's just nice to have it. If I have trouble this time I'll definitely use a zip tie. Little update, called the machine shop and they said they removed only about 0.003-0.004 inch when shaving the head since mine was relatively straight and I didn't specify how much to remove so they removed as little as possible. Gives me a little more confidence my chain is just extremely stretched and a new one should solve it

Would you reuse the old cam gear over the cloyes one? I noticed that when ordering the kit. Should be getting the kit today and install tomorrow. Will consider, it was relatively easy doing it without a zip tie though.

No, I was able to hold the tensioner in with my hands while installing it.

No worries my friend. I'm listening in on what everyone is talking about and taking in all the knowledge to use as future reference and as a guide for when I tackle the chain on Tuesday. I'm hoping just replacing the chain and tensioner will resolve the issue, if not I'll have to mess with the guides and modify them assuming the chain is not far from being where it should be and the tensioner isn't crazy extended like my picture. Otherwise I'll have to measure the head and go from there.

Will measure and see how thick it is. I actually remember seeing the OEM thickness of the head somewhere. Already replaces guides but I have an entire kit coming Monday and will install Tuesday. I'll update how it goes Tuesday night

That's actually a very good point and idea. I can't remember if I messed with the direction of the guides but definitely worth a shot. And assuming the tensioner slides in a little more with the new chain I may consider what you are considering with enlarging the slot to make it more even with the tensioner.

Wow that tensioner is expensive, what happens though if it doesn't tension it enough since it stops at a certain point, can't really tell how that one works. Wouldn't the thicker head gasket just make up for what I shaved off though? Especially just going back to OEM thickness head gasket? It's a stock L28 for the most part, n42 block and n47 head with stock efi.

I believe the OEM gasket is 1.2. I've ran 1mm head gasket before on a previous engine with a new chain and it was solid. I actually remember the tensioner sticking out slightly more than normal but wasnt excessive like what I have now. I suppose Instead of the shims I can just get a thicker head gasket and that would solve the cam geometry. What I will do is see how much the new chain and tensioner solves the problem, I think if it throws that tensioner piston back in at least 3-4mm would be good to run as is otherwise I might just look into a thicker head gasket even though I spent $300 on this one lol

Went ahead and spent the extra money to get a new timing chain set from Amazon so I'm not waiting, will knock it out Tuesday and hopefully solves my problem and I'll save the other timing chain for a rainy day. I ordered 0.015 cam tower shims too just to be safe but I really don't think I'll need them but just in case I do, do you guys think unbolting the head bolts and not replacing the head gasket is okay or do I need another head gasket if I do that route now?

Figures, guess I didn't think about that with the head gasket. The guides are new so yeah I replaced those, the old ones were worn. Okay, guess I'll have to either have to ask my friend to hold onto the car a little longer or pay a really expensive tow truck fee.

I believe the chain I have is the original one as everything I removed internally in the engine was all original so it's never been rebuilt but the engine was running before hand. I had low compression in all cylinders which made me do the rebuild. Do you think the chain will be fine for a 60 mile drive considering I could not force the chain out with my hands when the chain was installed? My head was resurfaced but the guy said not a lot of material was removed. I'll have to call Monday and find out how much they removed. I also do have a 1mm head gasket. The rebuild was mainly bottom end all new, head has new rockers and seals but same guides yes.

Oh wow, didn't even think to check Amazon either. I only ordered the chain though as the other websites only have everything as a set. I have spare gaskets and had new guides on hand so I didn't need the kit.

Run as is and just hope it doesn't pop out I suppose. When comparing with a picture of another tensioner completely out, it looks like mine still has about 4mm-6mm before that shaft comes out completely. I'd basically just drive the car back to my house (60 miles away from his house) and wait to install the new one chain before driving regularly. I ordered from Zcardepot. Didn't think to check AutoZone to be honest. MSA was pricer and still usually takes an entire week or two to get unless I pay for the faster shipping obviously but shipping is already expensive as is.

Will do, most likely will be able to do Sunday or Monday with him that's when we planned to start it. I remember the chain not being tight for me when it came to installing the cam sprocket. I have a new chain on order but I typically get that stuff in two weeks and he needs the car gone by Wednesday.

Yeah the entire engine is put back together including the cover. Car is at my friend's house and he is in a rush to get it out of there but after comparing pictures the tensioner looks alarming. I remember trying to see if I was able to extend it more by hand and checking to make sure it would stay put and it seemed like it wasn't going anywhere. My cam sprocket is placed at #1. Should I adjust it to 3 or would that be difficult with the timing cover on?

I just did a rebuild on a L28 engine however I stupidly did not order a new timing chain or tensioner so I reused my old ones. Engine is already placed back into the vehicle but before turning keys just want others opinion on if this tensioner being extended this much is acceptable for a first start and break in? The chain has good tension and somewhat acceptable slack. Rotated the engine multiple times too didn't see signs of it being a problem at least by hand. Any insight would be appreciated.

Okay, for the most part all the ring gaps for the top compression ring measured at 0.45mm - 0.48mm while the bottom compression rings measured 0.4mm. According to the factory service manual, the rings are to be between 0.23-0.38mm so my compression rings from Hastings are slightly larger but after looking around on their website it's within spec for what they recommend with the ring diameter. Me and all my co workers think it'll run fine and won't go through oil. Anything can't be worse than how my previous engine was burning oil. Had to add a quart almost every 600-800 miles. I did take a engine building class years ago so I'd like to think I'm not that stupid to sand my walls down haha. My next step is to check the head after I get the rings installed. I'm missing one of those damn exhaust liners but supposedly it'll run fine.

So basically the rings are meant to fit without any gapping? They seem to be gapped slightly larger than what OEM recommends which I'm seeing is 0.015 or 0.016

I will get back with how the engine performs once it's complete. Made a lot of progress since. Measured everything and everything checked out. Crank was good, wall measurements were good, thrust was good, no warpage on the deck, everything was within spec. Recently checked with a plastic gauge with the new bearings and everything was pretty much perfect within spec. Crankshaft is back in the the block and installed. I am now stuck at the installation of the piston rings. I have a standard size set of rings from Hastings and can't seem to find information on ring gap size. Are aftermarket rings gapped differently than OEM? My top ring gap measures at 0.017 with a feeler gauge. Any insight would be appreciated on this part.

Yeah he used a ball hone. He went pretty dang fast if you ask me. I think a lot of it has to do with the camera making it look sharper than it really is because I see what you mean but in person looks different. Based on my eye though and trying to feel for scratches etc you can't feel anything. For now I'm going to take the chance with new rings, bearings etc and see how the car performs. Worst that can happen is I burn oil and have to pull engine again which I'm okay with. $3500-$4000 is a lot compared to $300 and for the price difference I'm willing to sacrifice some time and extra work if need be.

Just wanted to get back to you guys with some pictures. I went ahead and removed the pistons and cleaned them up. Crank looked pretty good overall. Went ahead and polished the crank by hand and looked even better, zero scoring that can be felt with the finger nail or thin plastic gauge. For the most part the journals seem to be even based on how my co worker measured it. Cylinder walls my co worker went ahead and honed it and if you ask me looks very good. Measured the bores and they are still at a perfect 86mm like when I measured before the hone. Going to take to a machine shop in a week or two to have them clean up and do some fiber measurements.

There is actually two Z specialty shops I will give em a call today if they are open otherwise I'll take a look at jasper too! Yes, actually one of my other co workers stated it's a high mileage engine by the looks of it. I had another engine before this one and it looked a lot worse inside and was burning oil like no tomorrow. My co workers have the tools for the measurements, so either today or next week I will respond with some measurements of the crank. One person responded to me that is selling an engine too, going to look at it on Tuesday with an endoscope and see what the walls look like the the pics he took of the block does not look promising and he told me he had overheating issues and low compression from a blown head gasket. I actually wanted to get the block decked. I wouldn't mind bumping compression closer to 9.1 if it wouldn't effect my chances of passing smog. I know, very thankful for the responses and quick help with this. Taking everything into consideration and looking into possibly just getting the entire engine bored and machine if the measurements don't look good. However my co worker still wants to try an just hone the walls to see what the results are, he thinks the verticle lines are not a big deal because we can't feel them at all even with a very thing plastic gauge. Haha, well my Z has been down for almost a year been saving up since then in hopes to get the car back on the road this year. I wish could say the same thing you do haha. I'm actually going to look at an engine next week however the guy said he had overheating issues and a blown head gasket. For some reason he rebuilt the head but not the block, outside of the block doesn't look nice so gives me concerns the block is not good, but I will bring my endoscope to check.

Well, whatever method they use to clean blocks I want to have done. The original place I called TopEndPerformance actually led me to another shop but the guy I talked to said he wants to bore then hone too. They have reman engines still? Where? Not without doing measurements, I got the bearings out. It won't let me post the pictures with my phone but the main bearings are down to the copper while the connecting rod bearings look good. Almost no scoring on the crankshaft, very very minor a polish will clean it up nicely by the looks of it. Tomorrow I'm going to get thrust measurements before removing crank. The engine won't be sitting, either it'll get the work done with or without the bore unless I get lucky soon with another engine. That is for L24 and L26 I believe though as they don't show for 280z. I did contact MSA and they said they don't have anything. I'll try zcardepot next week. That's not too bad of an idea, just would be scared on how much material can be removed from the top of the flattops and that would make the pistons weaker?