Well, almost. The original “arose from it’s own ashes”, while mine is just being rebuilt in it’s own garage. I started with a big Garrett GT28RS, which eventually broke and was replaced by a slightly better GTX2860R. As it evolved, the engine bottom-end was upgraded to CP Carrillo pistons and rods, which proved to be not enough for all the boost it produced. My original build thread is https://www.northamericanmotoring.com...ml#post3240122 and was updated gradually over about 5 years.

It’s final day is described in this thread https://www.northamericanmotoring.co...ml#post4236091 along with the decision-making process of what to do next. It includes an interesting discussion on what actually caused the damage —- tuning or hardware selection. I consider the participants knowledgeable, and I value their opinion, but I’m a very hard-headed old fa —- uhhh, fogey, and chose to not follow their advice to change tuner. Instead, I’m lowering compression, beefing up the engine bottom-end, and lowering boost from 30 to about 25PSI. After break-in, I’ll make the trip to Tempe (ironically, a suburb of Phoenix, AZ) for another tune (same tuner) —- one that matches the different mods. This time, I might use a trailer instead of driving it, I’m not as confident as I used to be —- TBD.

Anyhow, the first thread has an inappropriate title (with the original turbo), and the second thread describes how it died. This thread is intended to document the rebuild and its results. I don’t expect to beat my previous 361WHP, at least not at 25PSI, but that too is TBD. 30PSI boost is just a simple adjustment away.

This is the way my half of our garage has looked since August —- stripped engine compartment and parts all over the floor.








Here’s the new stuff going in. Most of it has been waiting in the trunk, a comparatively clean area. New (to me) engine block was also on the floor, until it was sent out to a shop for cleaning and / or upgrades. Now that the upper half has been returned, rebuild can start. All of the old parts that’r re-used will be thoroughly cleaned during re-assembly.


These are the Cat Cams, not yet tightened down, just being kept someplace.


Note the new balancing "hole", drilled in one of the center counter-weights. Also just being stored here 'til assembly time.


A box full of gaskets, bearings, guide pins and other dealer stuff. Note the head gasket is from Cometic.


New 9.0:1CR pistons and ARP studs for mains and head.


Dealer's timing chain repair kit --- really cost effective compared to separate prices.


Items of interest include what CNCWerx did for me. Here’s a set of comparison pics of the water jacket on the original destroyed block and the rebuilt version.




And a close-up of the O-Rings installed to “~ help pinch the headgasket around each cylinder reducing the chance of "blowing the headgasket."*“


Both the head and block have had their mating surfaces "flattened", so between that, ARP studs, and a Cometic gasket, I should have minimized compression loss. 'Course, there's always other ways --- blown piston or valve, etc.

Now to prep for assembly --- oil squirters in each cylinder, main bearings (not to forget thrust bearings), oil seals, block halves guide pins and sealant. Selecting proper bearing color was a challenge, for me and the dealers parts guy. He had to get info from a service tech on how to translate the factory ID system --- this is a relatively new dealership, in a community where most Mini's are OEM, minimal mods, especially "shade tree mechanic" engine work.

Then fit the piston rings, install rods, new timing chain, then flywheel. Gotta use a scrap flywheel 'cause my OS Giken is one made before they knew it needed a 90 deg locking pin hole. Makes for an even more painful process.

Then, to do a valve / piston interference test, I gotta find an old head gasket, a bunch of old head bolts, and assemble the head to the block. Still gotta shop for some modeling clay. My tuner, EuroTechsAZ, has also been advising me, furnishing parts and info, and has been extremely helpful!

But, I'm getting way ahead of myself. Probably gonna take a full day (my days are pretty short) to just get the block halves together. I'm slow and really want to be careful.

 

From whom did you get the 9.0? Are they custom made?

 

Yes, custom made by CP. About the same cost as off-the-shelf versions, but 3 - 4 weeks delivery. Got the heavy-duty wrist pins too.

 

Really cool.

 

Gotcha. With the lowered compression ratio, but a 25 psi you still have a really high dynamic compression ratio. I wonder why not using meth?

 

O-rings plus a Cometic gasket?

 

I'm still planning on using my original HFS-4 at 80 - 20 WMI ratio.

Overkill???

 

ahhh perfect. Any special setup with your HFS4? Gian? Thres?

 

The only adjustments I made were to have it start squirting at positive manifold pressure. This was done on install, when it ran on 50 - 50 --- no changes when mixing 80 - 20 --- for the last several months of its operation. Might need to tweek it after the upcoming break-in (no WMI during break-in).

 

Cometic's have an O-ring. You are going to have problems if you try to use both.

 

Took a quick look at the Cometic --- seems to have a "thin area" where my o-ring will meet it. Cometic is 3 obvious layers, firmly connected in a few places, and has a "raised" or contoured surface. Compared to OEM, it's 3-D. I'll measure both gasket and O-Ring tomorrow, to see how they'll interface --- whether or not the "rings" the same size. Pic in my 1st post might not show it, but the O-Ring is slightly raised. I'll also compare it to my old gasket.

Spent a few hours today putting together the two engine halves --- "gasket-in-a-tube", assembly grease and thread lube everywhere! Gonna work on fitting the new rings next, then assemble rods to pistons, weight balance each set and install them. Really want to measure piston to valve clearance, but gotta install all the stuff for timing chain first. Can't just work from the inside out, or top to bottom --- gotta be done "systematically". At the rate I work, and with interruptions, it's gonna take a couple days just for the ring and piston assembly.

Working with a local turbo repair guy for a turbo CHRA. Should have that in a couple weeks --- the last big-ticket item, I hope. Also found a couple more o-rings needed for oil passage plugs, between flywheel and block --- missed them when ordering OEM parts. Could probably get by re-using the old ones, but that's the last place I want to dig into to fix a leak.

 

Maybe really getting ahead of things...but are you doing for oil cooling?

 

Aftermarket oil cooling isn't in the plans. For my typical driving habits --- DD and minimal track, I don't feel it's needed. OEM oil system seems to be working fine for me. Plans do include a good oil system flush, but that's only the pump, filter housing and a couple hoses --- crank, head and block have all been hot tanked, etc. after machining.

 

Another milestone --- got the rings gapped, then installed and weighed the piston / rod assy's with bearings. Lightest of the four was 830.690 grams --- heaviest was 700mG more. Other two were 100 & 150 mG more than the lightest. Pretty good distribution, but I wanted to lighten up the heavy one, so after a bit of grinding and sanding, I got the 700 assy down to 30mG over the lightest. So now my spread is only 150mG --- pretty close to what the big guns use for target tolerances.

Since all the parts were pretty much "virgin", I convinced my spouse to let me use the dining room table for the scale setup. Winter is here and my garage is insulated but is still pretty cold, and I'm not that tuff any more, so inside is good for close measurement work. Had this scale for ages --- long before digital stuff became popular --- works pretty good, as long as there's no draft.

Now to get them installed --- stay tuned.

 

Glad it's all coming together. I'm curious did you sand the actual bearings?

mQubed Motorsport, Manic Tuning Dealer

 

I have enough experience to know better than that --- bearings are still virgin. I found an article on balancing that shows where to add / remove material for pistons. Rods were done separately a month or so ago, so they weren't suspect. Only the pistons have excess material for removal, and 650mG or so isn't really that much. Piston spec sheet says piston weight is 264 --- probably in Grams, units aren't specified.

 

I'm reading this with enthusiasm.

One guy was asking you about whether losing the tear drop shape on the top of the piston matters. I have taken my mini to just under 8.0:1 and therefore had to have the piston top pattern removed. I have not noticed any issues at all. Idles fine, powers fine.

I'm just repeating what you have already said OBW, but just take your time, no rush and you want things just right rather than have to take it apart more times than planned. Good luck.

Cheers,
Steven_RW

 

With custom 9.0:1 CP's, there is only a "dish" on top, with a couple intake valve reliefs --- no contours or shapes. I would expect Stephen's <8.0:1 versions to have an even deeper "dish".

As for progress, pistons are installed, just prepping for a piston-to-valve clearance measurement. Hard part is converting some hydraulic lifters to mechanical. EurotechAZ, my tuner of choice, donated a few old ones for me to try, along with instructions on how to do it --- I'm clueless! My original plan was to find a syringe with an extra large needle, and inject epoxy thru the top bleed hole. Multiple problems --- epoxy is too thick to suck up into the needle, even the 24 hr cure stuff. Can't get all the oil out of the lifter. Then the lifter interior has a "check valve" to make needle insertion difficult. And as epoxy is injected, there's minimal air/oil relief --- epoxy has to displace whatever is already in there, and the needle is taking up the escape route. So, after wasting a syringe, needles and some epoxy, I did it the way Jerry originally suggested, more or less --- pull out the plunger, clean out the oil, remove the spring, fill it with epoxy, re-assemble to correct length, set aside to cure. That's where I'm at currently --- curing. Due to holidays and other higher priority personal commitments, it's gonna be awhile before I get to the measurements.

Stay tuned ---

 

Finally --- P2V clearance --- intakes measured 0.352", and exhausts were about 0.150". Only measured one cylinder, but all four valves. Had to do it twice 'cause the first time, I didn't tighten all the cam sprockets enough, and one slipped on the cam. Didn't cause any damage, just a PITA to take it all apart to do it again.

Probably didn't need to measure this clearance --- my 9.0:1 CR pistons have a nice-sized dish. The modeling clay only showed valve action near the outer perimeter of the piston. And, like OEM pistons, only the intake valves have a piston relief notch --- exhaust valves are slightly smaller and have less lift. Cat Cams makes a higher lift cam, as does Schrick, so it would be a good idea to measure P2V clearance carefully on those versions.

Now for some more assembly work --- install the head, time it, clean my OS Giken clutch / flywheel and replace my scrap OEM flywheel (used for its locking feature --- my Giken was made before they realized it needed the crank locking feature), clean out the transmission bell housing --- it's nasty in there, assemble the engine to tranny, add a couple more bolt-ons, then think about putting it back in the car. Hope I remember how it all goes back together --- been a few months.

 

All of these go in a N14, right? I cant imagine doint it in a N18 (the cam work)

 

Yep --- '07 MCS w/N14. I haven't looked for a cam upgrade for N18's, but I'm sure they're available by now. Shouldn't be that much more work and should provide even better results, considering the N18 has dual vanos.

 

OBW: good update.

Two or three small things that we experienced on our rebuild that I thought I would share. Expect you have all of them on your radar anyway.

1. The plug for the vanos solenoid can accidentally be swapped with the petrol tank relief valve plug. Both plugs reach each of the items and both plugs fit on each item. Most of the plugs are unique and cannot be accidentally put on the wrong item. But these two can...

2. For some reason the seal for the vacuum unit on the cam above the gearbox end got knocked out of place and damaged when we did our rebuild no matter how well we took our time and so on. It leaks oil that ends up showing as a drip on the bell housing bottom.

3. The crappy plastic pipe that leads from the water pump behind the engine round to the thermostat housing was quite awkward. The seal leaked like a beast and when we took it all apart again we noted that not only was the seal needing replaced but the actual plastic had become brittle and had cracked away a piece where the seal sits. Total builds were three to get it fixed right.. Each time having to take the inlet manifold off.

4. Experience to date is that nearly all 3 angle valve seats cut by engineering firms don't seal perfectly. They need hand finished for perfect seal. They tend to use a vacuum pump and gauge on the port and if it holds vacuum it is acceptable. Try blocking the port with a rag and put a compressed air nozzle in the back and build up pressure in the port. You can nearly always see air bubbles coming through the valve. I'm not sure if your head will seal as it has been done well by a pro with a reputation but worth checking. I bet you don't want to as taking it all to pieces to lap them in will be a pain in the *** :-).

5. We replaced our oil pump. It for some reason doesn't come with the one use bolt that you need to tighten the sprocket on to it. On the basis you MUST use a new bolt I cannot work out why it doesn't come with the expensive new pump.

Probably tonnes more I could type here and I reckon none of it will be a surprise anyway.

Clean the crap out of everything and then clean it some more and then some more again :-).

I more typed this out of support and interest on your build.

Good luck.

Steven RW

 

'Preciate the input --- hope your project is making progress. Happy holidays ---

 

Im unaware of any one doing cams for a N18, I thought installation, and proper adjusting them are a real PITA, more than any gains.

 

I'd expect your "proper adjusting" to be done by the tuner of choice. Why would the installation be any more complex than the N14? They only install one way, when using the timing tools --- it should be up to the ECU and software to control the Vanos.

But since I don't have an N18, I'm not that concerned with the specifics. However, based on my novice experience with Mini cams, the hard part is deciding duration and lift, then matching them to a set of pistons. And, as you say, the benefits are hardly worth the effort --- popular availability of really wild cams just isn't there.