Carter 71

Tower shim is not the cause, it's the cure, well in my case it was.

Just to add, didn't have to pull the engine out. Also, obviously had to reset the valve clearance too.

I had the same problem with my rebuilt L20B, at first I thought it may be the tensioner- I did put in a new one on the rebuild but maybe a bad part. On some internet digging it turns out all L series engines will get slack in the timing chain if the head or block has been skimmed, and the easiest way to fix this is to install shims under the cam towers. Did yours get skimmed, or has it been skimmed in the past? By wondrous Japanese design, the cam towers share the same bolt pattern and shape across the L range, and fortunately a Nissan/Datsun Z specialist down in Essex had a set on the shelf. They were in my hand the next morning. Installed them.... Rockers removed, Cam out, taking huge care that the timing chain didn't come off etc (zip-tied the chain) Shim installed, one at a time Totally sorted the problem. Running super sweet!

Need to get our trucks together in the summer, never seen another outside of Datmans compound, let alone two together.

Good advice! I'll get the PCV sorted on rebuilding Good to know some history, and thanks for getting in touch the other day. Now ordering parts needed for the rebuild, looking forward to getting it sorted!

That's just too much coin, with the cost of everything else, I'll likeley get the early 280z .040 pistons and rings unless something else comes up.

Not an option really, L20b is super rare in th UK, other L series still uncommon. Well aware of this yeah

Main/crankshaft bearings L20b or L28 ? Sorry, wasn't sure which you meant Thanks for the help by the way, the knowledge on Ratsun never ceases to amaze me, it's helped a lot!

Right, yes makes sense. Though am I right in saying dished Pistons from an earlier 280z/L28 would be better with keeping the compression down? Like part number ITM RY2700 040 for a '76 280z (I'm looking at Rock auto) Also, would the stock L20b rods and crankshaft be ok with these?

Yeah, I looked up custom and choked. Too much, a very last resort. I just spoke to my engine shop, they say they need to bore to 86.8mm to clear the damage. Is a lot, but not too much, as I understand it. That said, there won't be an off the shelf piston that size anyway right? I'm searching the net, and ratsun, but it's tricky on a mobile device and I'm getting bogged down in info I can't quite piece together lol

Ah right, thanks! I'll look into it

Thanks for a quick reply! I've not tried eBay yet, as I'm trying to keep the cost and time down shipping to the UK so trying to order in one hit, but will certainly look! So, pistons listed for an '81 510 would work?

I'm needing a set of Pistons for an L20b that needs boring out, amongst a heap of other stuff. I'm not sure on year of engine, but it has square exhaust ports, and it came from Australia apparently. I'm ordering a load of parts from Rock Auto but they seem to have limited stock on earlier larger Pistons, are later engine Pistons compatible? Any help, advice, knowledge, links are appreciated! I'm not doing the work, just the shopping #workshopgimp

Breaks are adjusted, work fine. Cheers! Yeah, a fire extinguisher In other news, engine needs a rebuild :(

^^^ that was over a week ago... L20b is in, 5 spd is in, prop shaft is shortened. As I said before, water pump was knackered, alternator wouldn't line up, and also had no fuel pump. Used the L16 items. Couple of engine flushes, and oil changes, and it's running pretty well considering the state of it. Smokey as hell at times, if it doesn't clear after a bit of running and another oil change then I'll look at getting some engine work done and such. I'll get the teething problems sorted, then look at the next steps. Had the inlet manifold blanked where the egr/emissions crap was... Gearbox is a little longer, made a 'stick gater replacement now... Chucked on my old suichuuka shift knob I had on my Sapporo, for fun like, until I find something else... So, happy as hell it's been done, but frustrated the engine itself isn't healthy.