jonbill

main journal is 55mm, rod journal is 50mm. I think it must be more or less impossible to install one in the other.

fwiw, my block that Ali pictured above is a mid 80s v57 LD block. It came with no crank case vent holes of any kind. We drilled and tapped it (1" NPT maybe?) and I fitted that hose connector.

2mm are small lashpads. do you have new valves? springs?

A wooden stand like this is handy for fitting the flywheel and clutch. its easy to make around an engine or sump with a bit of decking board. You can even put castors on it to roll the engine around. (corner needs to be cut away for the oil pump before use!)

its pretty normal for it to look very low on the gauge at idle and warmed up. I wouldn't worry about it as long as it ahows higher when driving.

Yes, it's a Speeduino ECU. I wasn't suggesting it as a solution, just evidence that the engine likes a lot of advance at idle.

its normal to run well or better with that sort of ignition advance at idle. I run 24° advance at idle during warm up to keep the revs up. The cam timing isn't really involved in how much ignition advance the engine wants. it might be involved in running like crap, but I'd ignore the cam until you've confirm the things the guys have mentioned. 1. confirm the engine really is at TDC when the pointer/pulley say TDC 2. check the vacuum advance works 3. check mechanical advance works 4. check what 'all in' ignition timing you have with a timing light (and no vacuum advance)

Try the green 'add files' button.

my flywheel lock tool. I think it came out of the scrap pile ready formed.

when it is in this "lean" state, does it feel normal to drive, or hesitant? 16s is prety lean and I'd expect you'd feel it, so if you don't feel any difference, I'd think it must be an air leak in the exhaust before the sensor.

That crank does have an auto adapter on the back there. It shouldn't be there on a manual gearbox. They can be quite firmly attached, but it will pry off.

the mounting is different for auto vs manual I think.

why not go bigger? 86.75mm is a bit of a meh size. many will have flat top pistons in 88mm+

I've had the RT mount for few years and used 3 or 4 diffs over that time. The diff is squashed between the RT mount and the Nissan mount. I have no noises unloading the diff (with any of the diffs) , but on the first diff and the current one I could get the clunk on loading it. The one that had no clunk ever did develop a serious whine and on checking, the pinion is worn. My conclusion is that the clunk in my case is down to the clearance between pinion and crown wheel, and I'm happy to live with a clunk occasionally if It means I'm not killing the diff!

are '73 style' pistons flat top? If so, it'll be pretty close I think. I'd mock it up with plasticine and check how much clearance there is.

Is your question about clearance between valve and rocker or valve and pistons?

I suppose you might get lucky and only have to take material off the new cap. maybe you could weld the new cap in prep. But I'd think just buying a complete l28 block would be easier and cheaper.

Here's an unmodified P90 (I think it's unmodified anyway!) So yours has been filled in quite a lot on the left side, and maybe also around the spark plug boss (but that also could just be a big skim maybe?) I'm surprised there's not more of a chamfer on that infill - isn't 'unshrouding' the valves part of head porting 101?

quite a lot I'd think, its a good start for a 300 bhp engine.

Yes! welding and grinding by someone talented, not me 😊

Yes, agree p79 also very good. Being pedantic, you don't *have* to skim it and shim it. There are better (if more expensive) alternatives.

Os giken TC24 is that sort of money. P90 is a great head. My one is anyway 🙂

what I read was that manifold pressure tends to atmospheric long before full throttle, so you get relatively poor resolution at higher throttle openings. I expect its less of a problem with smaller choke sizes and clearly many people have joined TBs and MAP etc working fine. I don't know microsquirt, I'm using Speeduino. If Microsquirt is MAP only, you might not have a choice.

I think there are downsides to joining the TBs, and limitations to using MAP for load. on my engine, I've only got the brake booster on #6 vacuum tap. I'l use TPS for load and my regulator is a constant 46psi. dunno about AC tho!

at the bottom end, there isn't a difference between compression stroke or exhaust stroke. theres just pistons going up and down. the cam timing determines whether a piston up stroke is compression or exhaust. so if the piston #1 is at TDC (determined by your screwdriver) and the cam dowel is correctly engaged with the cam pulley and the marks line up on the cam pulley and the thrust plate, then #1 is at TDC on compression stroke. Then if the distributor drive spindle is aligned 11:25 with the tang offset to the correct side (which side? can't remember!) then the spark timing is in the right ball park and the engine should attempt to run if you have sparks and fuel.