Yet another XU9/10 engine build

[Andy 105 1 Cars]

Hi Peter. 

Thank you. As I suspected. I will not be greedy ! My thinking is off the shelf 158mm rods with 20mm pins and custom pistons . That way I keep the costs under control and get exactly the CR and valve pockets I require. Having said that, the CP piston  for the Honda (Sc7046) are just about perfect and off the shelf. Snag is that shipped, they come in at around £750, I would have to assume that the valve pockets are in the right place and to the right depth and then get a custom rod as the 158mm RS rod is 1mm too long. I am still not quite sure . CP pistons are very good , but then I have heard nor read nothing adverse about Wiseco who would make my custom pistons if I go that route . 

Decisions .

 Andy

[Andy 105 1 Cars]

At long last. Engine build begins. First job is to check that my 157.8mm long rods fitted to the 96mm throw crank clear the inside of the block. On no. three, the clearance is 22 layers of masking tape. For those of you not fluent in masking tape units of measurement, that comes to 2.4 mm. Phew. Just got to check the other three cylinders and I can then start demurring the block.

[Andy 105 1 Cars]

It had to be done. A coat of etch primer followed by a coat of POR 15 engine enamel . At least one person I know likes the colour . Me 

Andy

[Andy 105 1 Cars]

And 4 hours of work later, one set of prepped mains caps, oil spray bars in place and a jizered crank ready for a hot wash ( read dishwasher ) . All rotating and reciprocating parts have been balanced . The crank was  an absolute mile out . Removing the balance shaft drive wheel obviously had more of an impact that anticipated. The Wiseco pistons were within one gram of each other to start with, ditto the Robson rods, so the ‘balance man’ had less to do there .

[Andy 105 1 Cars]

Hit a small snag,I checked the main bearing clearance and , to my disappointment , got 0.075mm across all 5 . Crank measured up perfectly at 59.950 consistently. And here is the snag. Ten minutes on the King bearing catalogue site revealed the problem, The  XU 10 crank should be 59.98-60.00 . The EW 10/12. 59.94-59.96 mm. In addition. The EW bearing housing is 0.025mm smaller in diameter and the combined bearing thickness 0.03mm greater than the respective XU dimensions . 

So , risk 3 thou main bearing clearance or regrind  the mains to 0.3mm undersize to remove the problem . 2.4 thou clearance is about the top limit ,  but I would be interested to hear others thoughts on this one . Dropping an EW12 crank into an XU10 block is not quite as easy as I thought !!,,,,

Andy

[Tom Fenton 1,524]

Regrind the only option for me...

[SRDT 146]

Check if the forged DW12 crank fit... but now that you have a balanced EW12 one it may be cheaper to regrind.

[Andy 105 1 Cars]

You are right about the DW12 crank.Same dimensionally as the Xu10  crank bearings . That one would work directly with the Xu10 bearings . Now cheaper to grind my EW12 crank . Bother .

 Andy

[DrSarty 90 1 Cars]

I thought DW12 cranks were rarer than hens' teeth, and 3 times the cost anyway (which is 1 reason you went EW12 I think)?

[Andy 105 1 Cars]

Hi Rich. Great to hear from you. The xu11 crank is hard to find. The DW12 engine is not so difficult. I found one in Burton on Trent after. 5 mins looking for £300 plus £50 delivery.However, a mains grind on my EW crank complete with new bearings will not cost that , so the latter is probably my way forward.How is your Xsara turbo project coming on ? 

[dcc 855]

The ew uses varying sizes of rod bearings iirc. I think they are colour coded on service box from memory. When we built the bottom end for a mates 206 turbo, we had to order a set of bearings to use as a measure for the plastigauge. We then had to order another set when we had a reliable reading to ensure it sat at the right spec.

 

I'm just wondering if there is a set of bearings which would take up the difference in clearance 

[Andy 105 1 Cars]

Hi. Thanks for the reply. It is not the big ends that are the problem, as they measure up as 50.00, it is the mains, that are bang on spec at 59.95mm but too small for the XU block which wants a crank at 59.982-60.00 mm , I have gone for a mains grind to 59.70mm and 0.3mm undersize bearings (ACL) which should do the job. I did not on service box that Peugeot list a whole range of big end bearings for the EW12 engine so I assume they were graded .

 Andy

[Andy 105 1 Cars]

Oh. And as for mains. I trawled through bearing catalogues from Glyco, ACL and King to see if I could find some mains bearings  that has the correct housing diameter but were slightly thicker . No luck. 

[Andy 105 1 Cars]

A bit more progress. Crank back from the machine shop with 59.70mm mains  , 50.00 mm big ends and some ACl  bearings to go with it. Plastigauged the mains , although a bit of an academic exercise given that the micrometer did not lie . Crank rear seal and hockey sticks in place , and the crank turns very nicely, all 96mm stroke of it . Flywheel cleaned and ready to bolt on with new bolts from Peugeot ( they also provided the core plugs, cam drive bolts, tensioner bolts and a few other sundry items . God bless service box ) 

 As soon as the flywheel and clutch are on, I will get the block onto the stand for the remainder of the build . 

[Andy 105 1 Cars]

Oh. Forgot to mention. Thrust  washers are King, Peugeot Partner ( diesel) and gave me an end float or 0.15mm 

[Andy 105 1 Cars]

Pause for cylinder head, so went onto alternator mounting round two. I have an engine mounting from an Xu10j4 engine. No idea what car it came from, but it is a neat mounting. Also have a full  fat Gti6  mounts everything to everything bracket which weighs slightly more than the Moon . Well, it did . Now I just have the alternator mounting bracket, but cutting it down was a bit of a chore, and I had to double up on one fixing so that one of the five engine mounting bolts also clamps the alternator bracket, with a dowel pin offering secondary location. The photographs put it better. One coat of paint, and all I will need is a Gti6 alternator . Lots of choice there, from 70A upwards, 

[Andy 105 1 Cars]

Cylinder head back from the machine shop. Pictures to follow. First job is to check valve to piston clearance at and around tdc before getting too excited .

[Andy 105 1 Cars]

Update. Valve clearance at tdc is fine. Inlet has 4.6mm and exhaust 5.2mm. Given that the inlet has a lift of 2.4mm at tdc and the exhaust about 1.95mm, I think I have enough clearance there. A bit more of a worry is the combustion chamber volume. I had assumed 39.1 cc and did all my calculations on this assumption, including the Wiseco piston spec. Having just measured said volume and got 43.5cc , my carefully engineered CR of  11.2 has tumbled down to 10.6 . And this is on a Cometic gasket 1.00mm thick . Serves me right for sorting the pistons before having the head finished .I will sleep on this one 

[petert 549]

Wow, 43.5cc is quite big. Guy must have had a field day in there. They do look nice. How close is the inlet seat to the head gasket face?  Perhaps you can sneak a bit with a head skim?

 

The inlet clearance is only just ok. Did you check at 6-10 deg ATDC?

[Andy 105 1 Cars]

Morning Peter,

 Tardy reply. Had to get some hard miles in ! Yes, Guy was quite busy in the chambers and then worked hard on the valve seats . As you have commented before, a 36mm valve is barely big enough to give the ideal 3 angle ( or 4) valve seat cut . He did the best that he could . Exhausts have worked nicely though . I have been thinking about a head skim. I could steal 1mm without running into the valve seat / head face problem, then get the valve cuttouts deepened to compensate , but it would then all be mighty close in there . Part of this CC volume increase is due to the valves not only having a thinner head but dropping slightly further into their seats after the seat cut . However, this is all my fault.I should have waited until now to get the pistons. The real bugger is that there are some Honda K20/24 pistons which have 7cc dish and 29.6mm compression height that would suit perfectly . Anyway, whilst I am thinking about all this, I will crack on with a bit of gentle grinding on the tops of the lifter bores to clear the inlet cam lobe, then measure the installed height of each valve/ spring and get the correct shims ordered , then block off the oil drain on the cam sensor end of the head ( the S16 head had a vacuum pump there )  and then confess to Guy that I might have underestimated the combustion chamber volume slightly ( for slightly read 10%) 

And finally, nope, I have not checked valve piston clearance at 6-10degrees atdc but still have two valves installed ( on super light springs ) and the piston / rod in number one so will go and check that 

[petert 549]

Are you using an S16 thermostat housing and cam sensor?

[Andy 105 1 Cars]

Morning Peter. Yes as I want to use sequential injection and COP ignition . However, the housing also held a vacuum pump so I have made a blanking plate. In theory, oil should flow into the housing and back into the head via the 16mm drain hole. However, I will use a camshaft seal ( fitted before I put the tang onto the camshaft) and blank off the oilreturn hole. 

Update. Started measuring the installed spring height. All inlets done . Up to 0.5mm difference between valves, which, if not corrected via a shim, would be 2.5kg difference in spring preload . That is a lot, so this really is worth doing . 

Also spent half an hour with the die grinder making room for those inlet cam lobes 

[petert 549]

M6 countersunk screws work better than F clamps.

[Andy 105 1 Cars]

Of course! Why did I not think of that ! I have been scratching about using the damn clamp on about 5 head builds now. Screwing the baseplate to the head would be much better. Thanks for that tip.

Measuring finished. Need to contact Precision Shims in your homeland as I am  now in need of some new bespoke shims .

Out on the road this afternoon. Time to do another FTP session. Not exactly looking forward to that!

 

[Andy 105 1 Cars]

Under spring shims ordered. Under lifter shims sourced that will get me close enough to measure accurately . Precision Shims in Straylia offer wonderful service and can provide shims in 0.05mm steps and at a really good price . Arrows want just under £20 per shim!