Sam's build thread

[metalhead]

You gonna come to Tamworth?

[sambb]

Yeah that's why I asked about layout. The first time Woods beat me was on that layout. After I did him by 5/10ths in the state hillclimb round there last year I couldn't figure out how I did it until it dawned on me that he was quicker on A2A because he got two straights against my 230-240hp to do the damage. Those first two times he was on older R888's though and said he got fresh R888R's before the state this year - that's my excuse for him beating me. ha ha To have gotten ahead of a 275 RS trophy R and an M3 in your beast though is pretty awesome - only 4/10th off an Elise 111R! I'd have to say the AR-1's are working just fine for you.

[sambb]

Oh and I think I'm out of the Tamworth round. I just don't think I've been that good a husband but i'll see what I can do. I'll check the Huntley dates, I've always headed there so I don't think this year will be any different. Are you still keen for Sep 5 at Wakefield?

Problem with Tamworth was that I had the cam cover leak and the timing belt/water pump leak hanging over my head. Realistically I never thought I'd get them done in time so I never really floated the idea of a weekend away up to Tamworth with the governess. Turns out I did pull my finger out and got all the work done this arvo before coming in to work and so could probably go now, but its unlikely. Sorry man I had said I'd go I know.

[sambb]

what I was greeted with when I got an hours worth of stuff out of the way. Nasty leak from the water pump.
So I can confirm that the tensioner roller stud for the BJX is M10 x 1.5 inside the head and M8 where the roller slides on. The M8 portion of the thread isn't any tricky thread so you can just use two M8 nuts snugged against one another to back the stud out quite easily. The fact that the stud came out easily meant that I was in a position where I could do the KR 16V 1.8L tensioner roller so I fitted the high tensile M10 x 1.5 x 68mm stud I'd made into the head (guesstimated 15Nm to seat it). Did a test fit of the engine mount bracket to be certain nothing was hitting the new stud. Turns out that if you use the KR tensioner the M10 stud can be more like 58mm as the tensioner roller is not as tall as stock.
Here is the hydraulic tensioner/damper removed and the IE idler roller bracket, tensioner roller stud and new water pump fitted.
The new Cat Cams adjustable cam gear fitted up alright. I cracked the bolt on the cam pulley before I untensioned the old belt by torqueing against a spanner on the crank pulley to make sure nothing turned backwards. The Cat Cams pulley has its own zero position reference but no VW BJX no 1 cyl TDC timing mark. So I too a bit of care with that transferring the cam pulley timing mark across from the stock pulley to the new. As an extra precaution I'd marked the old belt (and against the pulleys) and transferred those marks across to the new belt and pulley so that was certain everything was in the right spot. I also had to measure that the new cam pulley was the correct offset from the head. I'd heard that a lot of the aftermarket pulleys are a slightly sloppier fit than the factory one so I didn't chance it and fitted a new bolt (65Nm) and tensioned it up using a tool I made with pins that fit inside the lined up holes of the pulley face. Weighed the pulleys and the factory pulley is (from memory) 480g and the Cat Cams was unfortunately a tad heavier at 510g.
The new belt didn't have direction marks. They never are at work but for some weird reason I thought that timing belts had to be directional so I thought I'd check: Replacing a drive belt: does the direction of rotation matter? | Gates Europe
I had made a tool to tension the tensioner roller too. When you fit it up it points down below the brake master cylinder so if you make one don't make it too long or you wont be able to rotate it far enough CW. The 90 degree method that is in the Integrated Engineering vid I posted earlier is pretty subjective. You can hit enough tension for a 90 degree belt twist quite easily and then additional CW motion on the tensioner results in not much more tension. eg You feel as though 10 degrees of tensioner adjustment here or there gives a tension change on the belt that is hard to discern. Lucky for me I have my other engine on a stand and was able to cross reference the 'feel' of what 90 degrees of belt twist feels like on a belt that is factory hydraulic tensioned, so I was pretty sure I'd arrived at the correct deflection. If you were worried about trusting yourself setting up belt tension with the KR roller, you could still go to non-hydraulic tensioning with the ABF tensioner roller that I posted about earlier. It uses the stock 10 - 8mm stud and all you do is go CCW until two arrows line up, tighten the nut and then the internal automatic tensioner does the rest for you - no guess work. The 33 ft lb/44.5Nm torque value on the KR roller feels high but it is a 10mm stud and its good to know that it doesn't feel like it s going anywhere. The IE under-roller cup/spacer fit perfectly and stood the roller off the head a perfect amount that lined up with the water pump which was the only original thing left on the east face of the engine by now.
NOTE: when you do the 90 degree twist test on the belt, keep in mind that it will move the timing marks. The crank will tend to move a smidge CCW. After setting everything up I had a head scratching moment when it appeared I was a tooth out. I checked this and thought about that, but simply going around a few times and then bringing the crank up to its marks had the cam pulley where it should have been - so don't get caught by that. Go around a couple of times and re check before you go and drop your tension and re fit the belt!

Good news is once all the manual tensioner gear is fitted up, and the east side of the engine is jacked to the right height, the famously f***kIng infuriating to fit engine mount bracket goes in there easily because the tensioner roller doesn't sit out as far and the hydraulic tensioner is gone. You'd nearly do the conversion just for that! For my own OCD piece of mind I made a mark on the top of the engine mount that lines up with a mark I made on the tensioner roller nut/roller so that I can easily double check that the nut hasn't budged.

So I refit everything gave the engine a couple of little hits with the starter to check I hadn't stuffed up and then fired her up and dat dat dat dat dat rang out of the engine bay. Its amazing how fast a cold sweat breaks over your body and you feel like your stomach has hit the floor when you think the worst...…….. re checked marks good, turned over freely by hand good hmmm Feeling better that my valves weren't all twisted I thought it could only be two things - if when undoing the cam pulley I had managed to turn it backwards a tad it may have driven the oil pressurised cam phasing solenoid down a bit and I was hearing chain slap or a cover is rubbing. I'm not religious but I did thank every deity when I discovered that the top plastic cam pulley cover had somehow fit up too far in and was hitting. With a big wince I started it up again and all was fluffy. So far so good. You can detect an ever so slight rumble at idle if you really listen for it, probably worried placebo, from the new tensioning system (I'd read/heard that was likely) but nothing to suggest that the belt is over tightened or any of the components are flawed so I'm happy!
Now just have to work out a few tests I can run with nefmoto to try to see if adjusting the cam pulley will liberate some Nm's!!

PS In converting to manual tensioning with a KR tensioner roller, I don't see why you couldn't just remove the circlip on the tube of the damper and remove its piston/washers etc, and then cut the head of the damper off. That would leave you with the factory base bracket and idler roller and probably no need to go and buy an aftermarket bracket. The only caveats to that are you'd want to know that your idler roller is still in good nick and that if you used the ABF tensioner which tensions CCW that it wouldn't hit the remains of the OE bracket.

[metalhead]

Fair enough about Tamworth.

I'm not sure what to do at the moment - I can pick up some G/Soft A050s in the right size for ~half new price, 18 months old but never used still with stickers. But that's still more expensive than the AR-1s that I haven't worn out yet, and I presume that while they'd be great for hillclimbs, they probably wouldn't be much good for circuit use which I'd like to do more of next year.

[metalhead]

Nice work! I think we've all had one of those oh sh*t moments when there's a new noise after completing some work...

[sambb]

Don't even think. Just buy them. I've had so many slip through my fingers within an hour if dithering. No they'll be a hillclimb tyre. You could probably go to Wakefield and do 5 laps inc slow first lap but beyond that you'll murder them. Get them though. You'll be ruined for all other hillclimb tyres after that though.

[simon k]

I had the 'oh sh*t' moment with my old Focus - it started and kinda ran for a little bit, then wouldn't run anymore.... I'd left the little rod that fits on my dial indicator in #1 cylinder after I thought I'd be clever and use it to find TDC

[Sydneykid]

That's complex task Sam, well done

Cheers
Gary

[sambb]

well I can say after driving the car around with the new timing gear on it that it is really crisp, boosts faster with a much more responsive bottom end and has lost nothing discernible at the top. How much can belts stretch? The old belt/original pulley appeared a smidge behind the cam timing mark before I removed it - can a belt stretch far enough in its normal service life to have the cam off a touch. Well with the new belt and CatCam pulley on, the pulley timing mark (which I transferred across) was if anything the width of the mark advanced. This would be most likely due to keyway freeplay in the new pulley (which wasnt as precise as the OEM) and a fresh tight belt yeah? Either way the car definitely feels better down low, undeniably so, so in the short term I'm happy.