Project: Rebuild!

[Uncle Arthur]

Do you have a bicycle pump, or toaster per chance?

Jules

How about a left handed screwdriver?

[OMY005]

Do you have a bicycle pump, or toaster per chance?

Jules

Ha Ha, I have 3 pumps but sadly only one toaster.

Andrew.

[sabretooth]

Offers noted and appreciated. The bicycle pump and toaster won't be necessary anyway. :p

As for the gauges - they'll be handy but the block is difficult to move as it is without an appropriate vehicle to transport it all around in.

If I get time tonight I think I'll do the ring gap and clean the galleries!

[CT]

Nope. I have a post on miata.net to see if anyone knows the difference in seals, then I'll make a decision from there.

CT, the valve stem seals you gave me - what engine are you using yours on? Any oil burning issues?

Hi Sabre - sorry I missed this one. Those are the same ones as in my old race motor but obviously the set I gave you were from an ACL head kit that I did not use. Oil burning was not an issue, piston burning was something else! (For the record, I did two pistons due to a tuner not setting base timing correctly and bringing in about 34 degrees of advance by ~3600rpm - when it should have been been around 28deg total)

[sabretooth]

OK, it's been a while, and the story must go on!
Although, I'll finish off writing up the engine rebuild – I’m like, 4 months late with that… The engine is sitting in storage at the moment while I wait for a house to become available to move into, but here goes, all from memory…

So, the block setup. Four months ago I left you all hanging (obviously...) with the main bearings installed, the crank sitting in the block – and not a whole lot else. With Spectral’s gracious assistance, I acquired some mains studs and head studs, which I then proceeded to install under careful observation by The Stig (saboteurEK, aka sab2).

The oil squirters are probably the best thing to start with from here - if you do anything else such as installing the mains studs or even the crank - then whatever you'll just make things difficult for yourself when you have to actually do the squirters. Forget these, and you're going to have trouble with oil pressure. You don't want that...


Pictured above is how each squirter goes together. Bolt, washer, squirter, washer. What I did here (and can't be seen in the photos) is ensure that the bolt is clear of any debris, and that the centre moves freely. Oil actually flows through that bolt from the block and into the squirter, so you'll want its valve to be clear.



That's where you want the squirter to go. Yes, I've contradicted myself and have the studs installed there - silly me. So, proceed to bolt down the squirter, ensuring that the dowel in the squirter goes into the hole in the block:




First, a few photos of the relevant parts. I actually was expecting mains bolts, but to my surprise I did in fact receive studs. Contained within each of the ARP boxes was assembly lubricant (for winding the studs in easily), the studs themselves, washers, nuts, an instruction leaflet - and the obligatory 'shopping list' ARP sticker. The first two photographs are the head studs, and the third photograph is of the mains.

[sabretooth]

With the bearings done, you’ll want to get those mains studs installed - if you did it the other way around the studs are going to get in the way of the installation of the bearings. So, lube the bottom half of each stud with the provided assembly lube and drive the studs into the block until they are finger tight – don’t go any further than finger tight. Do this until all 10 are in the block. I lubed the bearings while I was there, too.


Grab the thrust bearings, and on the side with the vertical grooves smear some assembly lubricant. And carefully, somehow, stick them in place either side of the centremost bearing surface. Right after I did that, I stuck the crank in to hold the bearings in place. You'll eventually end up with something that looks as such:



Before any mains caps go on, this is probably a good time to point out the differences between them. They actually do differ, and the reason for this will become evident in the following photos:



First, there's a notch that looks arrow-like in the cap. These point to the front of the engine. Second, one cap is wider than the rest - the one saboteur is holding is a normal one. But, the one at the bottom of the photo is actually the one that goes on the centre crank journal - the width is to hold the thrust bearings in place and stop them from being spun. So you'll probably have something looking as such:



Anyway, that's it for now. I've got heaps more to write about - crank clearancing, installing the pistons, small end clearancing, thrust clearancing, torqueing the mains and more. Although, one thing I can do just quickly - I've picked up a new part - it'll go in before the engine's complete as it'll be a minor project:

[Sean]

Beaut write up mate - As always.

[sabretooth]

I think that the search here is broken - I had to use google to find my thread. But, found it. Here goes, again!

Now, it’s bearing clearancing time. What we need to do here is use the plastigauge to verify that the clearance between the bearing and crank isn’t too wide and isn’t too narrow.

Reorient all of the bearing caps so that the point of the small triangular arrow is pointing towards the front of the engine, and also make sure that the widest cap is in the middle over where the thrust bearings sit. Make sure that those caps stay at their respective positions on the engine. Fit the bearings (notched, without the hole) into each cap. Strangely, the wider cap doesn't have a corresponding wider bearing.

With that down, start with one of the crank journals and lay some plastigauge down:


Apply the crank cap, torque it down to spec and then remove it again. Measure the plastigauge squish, and you've got your clearance reading:


What I did next (but don't have pictures of) is measure the amount of thrust - ie how far forward and backward the crankshaft can go. Fairly straightforward. It's trickier with 2 sides to measure, so because I didn't have 2 feeler gauges, I just doubled the min and max clearances, pushed the crank to one extreme and then checked the clearancing. I'm sure there's a flaw to doing it like that... I can't see one though.

And now, the obligatory, \"Yay!\" photos:

[sabretooth]

The next logical step from here is the pistons. With the small end bearings in (courtesy of the engine machinists), I'm able to attach the piston, insert the wrist pins and put in the clips.

So here, we have the assembly all laid out:



Laid out on the bench are the pistons, rods, the clips and the wrist pins themselves. The wrist pins in the photo have actually been inserted into the pistons, the clips are in the white plastic packets.

So with some cloth to protect the rods, I clamped it into a vice, small end up. With a bit of assembly lube on my finger, I smeared it on the small end's bearing of each rod. This is then followed by doing the wrist pin, and where the wrist pin goes through the piston:



With the appropriate lubrication done, we've got the slightly tricky part of lining up the rod in its appropriate place in the piston and inserting the wrist pin so that it goes through both. The thing to note here is the piston and rod orientation. The tops of the pistons have recesses in them for the valves - get this part wrong and chances are you'll have the larger intake valves smacking into the small piston recesses designed for the exhaust valves. In photos a few posts down you'll see what I mean. Also, if you check back through the thread here, you'll see that the intake valves (top row) are larger than the exhaust valves (bottom row). So you need to match this when orienting the pistons. In addition to this, you need to make sure you get the rods around the right way! It wasn't really obvious which way is the \"right\" way for the rods, so I aligned them so that the stamped letter on their side faced the front of the engine.




And to keep our new assembly from coming apart, we need the clips. For me, this was probably the trickiest part of the assembly. It's very easy to scratch the side of the pistons, so eventually I figured the trick to inserting the clips out. The clips are circular, but still U-shaped - there's a gap in one end. Put the bend in the clip, with the two ends facing upward and out. While holding the bend down, use your fingernails to go around the ourside of the ends, and squeeze them together while pushing them in. Eventually they should go \"click\" and slot into the grooves of the piston which are designed to hold the clips. Do this for both sides of each piston, and you have this:



And at the end of it all, you should have this!

[sabretooth]

Moving on, the next step from here is to check and (if necessary) change the gap of the rings. Doing one pistons at a time, we need to push each ring down the bore, and with the aid of a gauge of some kind - check the gap of the rings is within spec listed by the manual. I used feeler gauges, but there are some better tools you can use - which I don't have!

So, here's one of the rings. I can't for the life of me remember which one it is, but I'm going to assume that it's the lower compression ring. I expect to be corrected here.


To start gapping - stick the ring in the block pretty much the same way as when putting the clips in the piston - end opposite the gap first, push in at the sides and then eventually put the gapped end in also. Then with one of the pistons, push the ring about halfway down the cylinder, trying to keep it as flat as possible.



And now with whatever gauge you have - check the gap is within spec quoted by the piston manufacturer. Once all rings for a piston have been checked, install them. I used a piston ring expander for the compression rings - the oil rings were quite easy to manipulate without causing bends or anything like that, so I did those by hand.



Do this for the other 4 pistons, and that part's done!

[Lev]

Great write up, and a lot of work! well done

Could I be really ignorant and ask why the crankshaft needed to be ground to the next undersize?

[sabretooth]

Apparently it had suffered some wear/damage which would just a regrind would not have fixed. The only choice from there was the next undersize, unfortunately.

[sabretooth]

Right, now it's time to attach the boingers to the crankshaft - and get some semblance of an engine happening. Since assembling the pistons/rods and applying the rings, we now need to fit the bearings to the bigends, drop the pistons down the bores, clearance the bigends and finally attach the pistons to the crankshaft. Here goes...

Pictured here are the bearings. They seem to lack the same holes that the mains bearings had for oil distribution.



Still ensuring that we have the pistons oriented correctly (so that the valve recesses end up going beneath the corresponding valves), we need to drop the piston/rod assemblies in. A good idea at this point is to put tape over the rod studs so that the studs don't scratch up the side of the bore as you drop them in. Don't put the big end caps on! Insert the bearings into the big end and the big end cap - but don't actually fit the cap.



Here's a rather important part - gap control. For preservation of compression and stopping excessive oil consumption, we want all gaps to be stepped, as opposed to stacked. Looking down from the top of the piston, starting from the top, we need to basically keep each ring's gap as far away as possible from the next. I personally would have thought you'd do this by putting the gaps 180 degrees from each other, but the Wiseco literature said to put the gaps 60 degrees from each other. So accordingly, I followed the book and rotated the rings to move the gaps.

Now I needed the ring compressor - without this I'd be having a hell of a hard time putting pistons in when the rings want to spread out to an outer diameter that's larger than the diameter of the bore. So, oil the lower section of the compressor, and clamp it on the top of the piston - enough to clamp all of the rings down. This doesn't need to be done tight - just enough to hold the piston in place.




With the piston appropriately lowered and oriented in the correct direction, use the butt of a mallet to slowly tap the piston into the bore. Keep tapping until the piston is all of the way down and finally meets with the crank. Slide the caps on and just do them up til they're finger tight. I then did the exact same procedure for the other 3 pistons. It was a pretty good feeling at this point - the last time I had that feeling was when I had the machined crank sitting in the block. I just had to give the crank a few turns at this point.

[sabretooth]

Back to the boring stuff. These bigends are going to need their clearances checked. So we get the plastigauge out again, and apply a strip down along the crank journal:


Once again - clamp it down to the factory-specified torque, unclamp, and compare squish with the gauge:


Now, put it back together!

And finally, one more clearance to check - the side clearances between the rod and crank:




Rinse and repeat for all four cylinders, insert the two locating dowels into the block's top surface and we have an assembled bottom end:

[sabretooth]

With the head bottom end done, it was time to finally unite the two. saboteur showed up on the doorstep for the union of head and block. The first task was to insert the studs into the block. They were all lubricated with the included moly grease, and inserted such that the tops of the studs were all the same height, and such that the threads of all studs were in the block. If all studs were just inserted to envelop the threads, then the studs would all be differing heights.



We cleaned down the bottom side of the head and the top side of the block, ensuring that any residue had been removed from each. Then with each of us either side of the head, we lifted it up and slowly brought it over the studs and then down. And, nothing being trouble-free - oil came out of the head and messed up my clean surfaces! So while saboteur strained to keep the head elevated, I quickly went around with a rag making sure that everything was clean. Again.
Once it was all clean, we lowered the head once again. The head sat a little proud, but appeared to have lined up with the dowels. That was nothing a few sharp taps with the mallet didn't fix. And it was on!



Next came fixing the head down with the ARP nuts. Again a little moly lube was used on the nuts (nothing sus!) and then the nuts wound down. Once again - never one to find trouble absent, the sockets I had were not deep enough for two of the nuts at one end of the block. So while the nuts were on, they weren't tightened beyond fight-tight. We assumed at this stage that ARP are yanks - these nuts had imperial measurements (ugh). Not to be defeated, the next day we went to AutoBarn and grabbed a rather deep (probably about 5-6cm) 1/2\" drive 1/2\" socket. A bit of twiddling (ie some decent leverage) and the studs were done up with a torque wrench. Understandably, saboteur wanted to minimise any accountability on his part if anything goes wrong - he kept the engine stand in its place while I torqued the head down to 70 foot pounds (there are those imperial measurements again). The order of nuts was a radiating pattern from the centre, gradually going outward. The Mazda book said 60ft.lb - and I nearly followed it too until saboteur found the ARP specs said 70ft.lb (or 80ft.lb if using engine oil instead of the provided ARP moly lube)



Huzzah!