When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well, it’s been over a year since my last update. During this time, I’ve been following and commenting on others, sometimes mentioning that I broke my toy again.
I left off in my last thread installing a 4-port WMI system, which appeared to be working fine. Then I started chasing a CEL for a diverter valve problem. I’m using an external DV that’s probably located too far away from the throttle body and uses intake manifold pressure for valve control (it was recently relocated). I’d get the CEL when shifting during hard acceleration. My thoughts were that the DV needed adjustment on spring pressure, so I was out doing some road testing on Hwy US50 when crash-bang, it quit! Called AAA, got about a ¾ mile tow home, and let it sit for a month or so while I decided what to do and when to do it. Actually, I walked home to call AAA, and while I was gone, Nevada Highway Patrol stopped and documented a dead car. Here’s a recent pic of the NHP markings —- car hasn’t been washed yet.
The decision process was —- troubleshoot to find the failure, and if estimated repair cost exceeded $2K, part it out or sell it. Under $2K, fix it. Troubleshooting started with compression testing —- zero on all four and “unusual” sounds while cranking. Pulled valve cover and found all exhaust valves open, with some rockers loose and laying on the cavity floor. Cams are still installed.
Invested in a borescope and found pitted piston tops where valves hit them. Cylinder walls looked OK. Exhaust valve contact looks like it can be ground out and smoothed.
More decisions. OK, pull the head and examine pistons —- gotta know if parting out or selling. While pulling the head, I found the crankshaft center bolt was loose —- probably the main cause of the failure. For those not aware, this bolt had a recent torque spec change —- from 50Nm+90 deg, to 50Nm+180 deg. I wasn’t aware at the time of my last rebuild so I used the 90deg spec.
Another unknown about this failure is the last valve job. I took only the head with valves, no rockers, lifters, or cams to the shop. When it was done, I was informed that I should do a “valve preload” check. After a bit of research, I found this is the process of setting / adjusting valve lash on mechanical lifters. Since we have hydraulics, I checked that valves were closed or open according to cam position. Seemed OK, but had no measurements to use for reference, so buttoned it up and ran it. Ran fine for about 2K miles then all this. Since then, I’ve learned there is a spec called valve height, that should be measured and adjusted any time a valve is replaced. So now I’m thinking this shop doesn’t have a lot of Mini Cooper head experience, other than just grinding / seating valves. The machine shop is one used by a local Mini indie shop. They do a lot of muscle car building too, so I trusted them. Mini rebuild talent is scarce in Northern NV. Anyhow, the unknown here is the final length of all valves —- they might have been just a bit too long —- OK for hydraulics to compensate for at low RPM but cause interference at high RPM. RPM and oil pressure are proportional —- for lifter operation? Supporting this idea is the latest dyno chart showing turbo boost decreasing from max by about 7PSI as RPM increase. Altho, this is probably just a weak turbo, I’m not completely convinced.
All that said, here’s a pic of the valves after head is pulled. Cams are not installed. Note the uneven coloring of the intakes, implying slight contact and possible low compression / turbo boost loss if it’s been continuous, and not a result of the loose crank bolt.
Pulled all 4 pistons and only damage found was dinged tops, no sidewall or any other damage. Pricing for repairs is now pretty close to $2K —- all new Supertech valves, some guides, shop labor, and lotsa gaskets / seals, so I’m gonna go for it, again. Took my Dremel to the piston tops, balanced them as a whole assembly, and put them back in the block.
This time, I used the latest torque spec on a new crankshaft center bolt. However, let me assure you that getting a full 180 deg added turn isn’t easy for a guy my age, ‘specially with the engine out of the car. My ½” torque wrench is a “two-bar” style, one bar pointing to a scale on the other bar, and 18 inches long. After 50Nm and about 90 deg, the wrench was pegged at 150ft-lbs and I couldn’t get any more turn out of it. Just too damn old and not as strong as I used to be. It took a 30” breaker bar to get 180 deg. During this tightening process, I found the oil pump chain wasn’t on the crank sprocket. Had to take the hub, sprockets, and guides out to re-assemble it all correctly, not fun!
Sent the head off to my tuner of choice, EurotechsAZ, who assured me his “head guy” knows how to work Mini heads. Should have it back, ready for assembly this week. I don’t expect to have it back on the road ’til January at least, and that’s optimistic.
Repaired head just arrived. Here’s pic’s of both sets of bent valves —-
All 8 exhaust are bent about the same. No broken ones, just bends.
Originally, I expected these intakes to be OK. NOT! I lined them up with the head’s wear pattern (noted as “uneven coloring” in previous post) alternately facing 180 deg opposite each other, to emphasize the not-so-obvious bends. Notice how the stems point in slightly opposite directions. Kinda supports my theory that my low boost at high RPM's was caused (or at least contributed to) by compression leaks.
Had a minor setback --- gasket kit for the head was the wrong one. ECS lists four different kits and I ordered the one showing valve stem and FI seals. Somehow they sent the one with all except the FI seals. Probably the most popular, and definitely the least expensive, just not what was ordered. After a bit of "discussion" with customer service, I was sent four separate kits with the correct seals --- no added cost. It did however take almost a week to get the parts --- weekend, holiday, and internal paperwork.
Anyhow, the engine is finally ready to go back in the car. Most of the "attachments" are back on, engine and tranny are together and connected to the hoist, and now I'm psyching myself up to this chore. Should be ready to get out there tomorrow and start the process.
I may have missed it but did you ever find out the reason for the failure?
Yes, pretty sure I caused it by not tightening the crankshaft center bolt to latest spec --- 50Nm + 180 deg. I used 50Nm + 90 deg, the original spec from ten years ago. There's also the possibility that my first valve replacement wasn't done properly --- the valve height might not have been checked / set, and the valves were all too long.
OBW, I feel your pain every day. It gets tougher the older you get. I use to do marathon wrenching sessions when I was in my 30's and 40's but now I'm good for an eight hour shift them I'm done. You said the engine/trans are attached to the hoist so I guess you don't have a lift to work on, neither do I. A couple layers of cardboard on the floor are your friend, they cushion you when you're moving around on the floor and also insulate you from the cold concrete.
OBW, I feel your pain every day. It gets tougher the older you get. I use to do marathon wrenching sessions when I was in my 30's and 40's but now I'm good for an eight hour shift them I'm done. You said the engine/trans are attached to the hoist so I guess you don't have a lift to work on, neither do I. A couple layers of cardboard on the floor are your friend, they cushion you when you're moving around on the floor and also insulate you from the cold concrete.
Good luck and keep us posted.
Thanx for your concern. Nope, no lift, however there's lotsa cardboard plus a couple very old chaise-lounge cushions, maybe 2" thick --- almost makes it pleasant.
Todays progress --- after lotsa wrestling, engine is in! Axels installed and wheel hubs reconnected. Tranny linkage bolted up, fuel lines connected, clutch slave cylinder connected (no need to bleed it 'cause the lines wasn't disconnected, just unbolted the cylinder and moved it out of the way). 'Nuff for one day. Tomorrow, after refilling my kerosene heater (predicted high of 35deg F), I go for the t'stat housing and associated hoses, then start with the engine harness. Gonna wear out my cushions crawling around under the car.
Today's efforts --- t'stat housing installed. Most of the engine harness is connected, just the MAP/T and O2 sensors remain. Those will be connected after the ICI pipe, turbo and exhaust system is installed, hopefully tomorrow. Still a lot of harness to connect, mostly stuff under the fenders --- but saving that for later. I'll finish the t'stat plumbing when the front end goes back on. Since the AC was taken apart, I'll still need some local AC service, so I'll consider that effort to be the finishing touch. 'Course, since it was taken off the hiway in March, I discontinued my insurance. That in turn prevented me from renewing registration, so there's some "paperwork" to be done before it hits the streets again --- saved a few bucks tho.
Spent today connecting the exhaust system and the remaining engine harnessing. Changed a coolant hose to the turbo 'cause the one I had in there was too short causing a branch to be awkward to route. This was a custom hose, needed to adapt the big Garrett --- it had been bugging me for a long time, and this was the best time to fix it. Had to replace a couple hose clamps too.
Next will be putting the front end back on. This will require some metal cutting, to make the ICI pipe fit a little better, so not expecting to get a lot of harnessing connected. Cut metal wants to be re-painted, which will take time to dry.
Didn't spend a lot of time on the car Sunday --- watched a couple NFL games. Had to support my favorites!
Today, the major part of the front end went back on. Dremel'd some more of the support framework away from the ICI pipe, but it's still wedged tightly between the support and head. Should settle in (loosen) a bit after some miles are put on. Gonna take a closer look at the installation location. Maybe I can move it lower (away from the frame) and closer to the fender (away from the head).
Next will be the rest of the front end --- trim, bumper, grill, etc., and the associated wiring. Also air intake, DV system, boost controller, coolant temp gauge, and who knows what else, gotta be something I'm forgetting. Then fender well liners, tires, add fluids, connect battery, say a prayer or two, and do a compression test to get oil and coolant circulating, while I build confidence.
If the valves were not correctly installed you would have had problems day one. Those valves are bent from timing. Valves that are too long would hang open and not allow good compression. Been there done that with improperly set 350 Chevy rockers.
If the valves were not correctly installed you would have had problems day one. Those valves are bent from timing. Valves that are too long would hang open and not allow good compression. Been there done that with improperly set 350 Chevy rockers.
I gotta agree with you when valves are “excessively” long. However, if you have some time, consider this scenario for valves just “slightly” long:
During my re-assembly process, I checked valve-to-piston clearance. This was done by obtaining 4 new lifters, measuring their length, then taking 4 old lifters apart, removing the springs, filling them with JB Weld epoxy, squeezing them to the same length as the 4 new ones and finally letting them cure overnite.
This gives me 4 solid lifters that won’t compress during cam lift. My first observation was that all 4 valves remained slightly open when cam lobe was opposite the rocker arm. In spite of the “long valves”, there was adequate valve-to-piston clearance.
Prior to installation in the head, the 16 lifters soaked overnite in a bucket of oil. This was done to ensure some oil was in each lifter. When cams were installed, all valves were closed when not on a lobe. This implies that during normal operation, the lifters compress slightly due to the valve spring pressure.
Now let’s assume all valves have excess “installed valve height”, say 0.010” over spec (an arbitrary number). These valves may or may not close when they should, but probably will during low RPM conditions (low RPM corresponds to low oil pressure). Performance will seem to be normal. As RPM’s and oil pressure increase, lifter operation will become “stiffer” and less forgiving of valve spring pressure, eventually leading to valve float. Now consider the Vanos function —- variable timing. This can cause valve-to-piston clearance to decrease. With our “interference” engines, this can be catastrophic, and I believe this is what caused my failure.
In my particular case, a dyno chart shows boost dropping from 28 to 21PSI as RPM’s increased to max. One theory is the turbo is max’d out. I believe the valves were slightly too long, causing float and loss of compression / boost. This is supported by slight marks on the piston tops, just under each intake valve.
Another consideration —- when the machine shop returned the head with new valves installed, I was told to check “valve lash” (I didn’t furnish cams, rockers, or lifters). “Valve lash” is only set on mechanical lifters! It is not adjustable on hydraulics. This leads me to believe the shop didn’t check / set “installed valve height”, and they didn’t use OEM valves, they were all Supertech. Anyhow, I went home and researched “valve lash”, and decided I couldn’t do anything about it, so I trusted the above process and proceeded with the re-assembly. Since I used the wrong torque spec, there’s no way I can definitely say what the failure cause was —- probably the loose bolt caused the exhaust valve failure, and intakes were caused by excess height.
Well I guess any problem can be over thought until a solution is discovered 🙂 my piston tops had slight marks from the valves just touching them slightly. It didn't bend them but they definitely left a mark. I got lucky, but I bought the car knowing it possibly had a blown engine.
valve lash is adjustable on hydraulic lifters of some engines, but it's more of the RONCO "set it and forget it" kind of thing. It sure would be odd for a shop that does this for a living to install the wrong length valves. That's kind of grade 8 stuff. You measure the valves THEN you order the new ones. Then you get the specs for the installed heights and cut your seats to that spec. This is basic stuff for people who do this every day. Now dont get me wrong being human beings we all make mistakes. Hell I've got a list a mile long 😎
good job on the build by the way post some pictures of the Garrett once I get my own engine straightened out I'll be looking for some upgrades.
Well I guess any problem can be over thought until a solution is discovered 🙂 my piston tops had slight marks from the valves just touching them slightly. It didn't bend them but they definitely left a mark. I got lucky, but I bought the car knowing it possibly had a blown engine.
valve lash is adjustable on hydraulic lifters of some engines, but it's more of the RONCO "set it and forget it" kind of thing. It sure would be odd for a shop that does this for a living to install the wrong length valves. That's kind of grade 8 stuff. You measure the valves THEN you order the new ones. Then you get the specs for the installed heights and cut your seats to that spec. This is basic stuff for people who do this every day. Now dont get me wrong being human beings we all make mistakes. Hell I've got a list a mile long 😎
good job on the build by the way post some pictures of the Garrett once I get my own engine straightened out I'll be looking for some upgrades.
I really can't place all blame on the shop. They ordered Supertech parts for my engine, I just don't know how much TLC went into the install. These guys do a lot of muscle car work, and probably deal very little with hydraulic valves. My thoughts are they skimped on looking up the specs, or used a yardstick for measurement. Also my theory on how the hydraulics function is just that --- a theory. I have zero experience working with hydraulics, and have been away from serious engine rebuilding for 40+ years.
As for the Garrett, if you work backwards thru my threads, you'll find some of the recent pics that show it. Since the air filter has been relocated to accommodate the added WMI plumbing, I'll take a couple more, just to have them in this thread. And, if my tuner is correct, the Garrett GTX2860R is too small for this build. So depending on how big a build you do, consider a different turbo. I'm looking at their newer G25-550 or -660, smaller frames so should spool quicker. Borg Warner EFR series is good too. Does the mod bug ever stop???
Does this car thing ever stop? LMAO. I'm pretty sure most old muscle cars, if not original, are using hydraulic roller lifters. You'd be mad to go any other way. All the power is there and the heads. I've got a 64 Cadillac with FiTech fuel injection I've installed. I've also installed a vapour canister to catch any errant fumes and next I'm installing a couple high flow cats to really clean it up.
I will look at some of your other posts, thanks
About all that's left is mount the tires, top off the fluids and try starting it. Gonna mount my ice tires --- they're getting old and still have lotsa tread left. I want to get them used up before they're 8 - 9 years old. Already put in 4 ½ gts of oil but still a qt low. I guess that when the head and block are drained and the oil pan is wiped clean, it needs more than the user manual says. Coolant takes forever to distribute and fill all the nooks and crannies. I'll be watching the level as I get it started.
Did a compression check --- numbers are low 'cause of my cheap Harbor Freight hose fitting --- extra large diameter. At least they're consistent.
Hope to get tires pumped up and installed tomorrow. Just gotta wait for the wife to bring the 2nd car home so I can connect my 12V pump. Don't want to use the Mini battery for tires 'til the battery gets a better charge on it.
All ready to try starting. Want to take a video during the initial cranking and "feathering" the gas pedal. Last time I started after rebuilding, the cam lope was very noticeable. Not so after it warmed up and oil was distributed. But now, after taking these pics, the camera battery is too low for a video, maybe tomorrow.
As promised earlier, here's some pics of the Garrett GTX2860R, this one with half the OEM shield that's still useable, and the 3" five bolt catless down pipe.
Side view showing the 3" inlet, tee for OCC return, 3" to 2 ¾" adapter for MAF, then K & N filter. Not gonna be fun to change oil filter.
Opposite side showing the external DV at the OCC tee, and a manual boost controller.
Complete engine bay.
ICI pipe and framework mods needed to make it fit. The pipe clamp is to protect the pipe from rubbing against the head bolt, not to hold something together.
ICI pipe showing one of the WMI inlets --- orange elbow at bottom of the pipe. Note the pipe's "battle scar" from previous runs without framework mods.
That looks great, talk about tight LOL. What HP are you producing? I definantly think a cold air charge pipe is in my future. I don't think three inches but at least one that doesn't look like a wrung out rag. Keep us posted.
That looks great, talk about tight LOL. What HP are you producing? I definantly think a cold air charge pipe is in my future. I don't think three inches but at least one that doesn't look like a wrung out rag. Keep us posted.
Tight is an understatement! Definite hard contact during hard acceleration and the engine is torquing (front end lifting). But I don't really notice the added vibration due to the adrenaline rush and concentration on fighting torque steer. Drives the spouse crazy tho!
The 3" cold air pipe is due to the turbo inlet size, I only reduced it to 2 ¾" for the MAF --- the "weak link" in plumbing diameter.
Looks like my initial "fire-it-up" will be delayed for about a week or so. Talking with my tuner, EurotechAZ, there's been a noticeable increase in our Mini community of crankshaft center bolt working loose, causing timing failure. He's working on a fix and I'm scheduled to try it. After my last repair (this bolt and all 16 valves), I'll try most anything to prevent it loosening again.
All ready to try starting. Want to take a video during the initial cranking and "feathering" the gas pedal. Last time I started after rebuilding, the cam lope was very noticeable. Not so after it warmed up and oil was distributed. But now, after taking these pics, the camera battery is too low for a video, maybe tomorrow.
As promised earlier, here's some pics of the Garrett GTX2860R, this one with half the OEM shield that's still useable, and the 3" five bolt catless down pipe.
Side view showing the 3" inlet, tee for OCC return, 3" to 2 ¾" adapter for MAF, then K & N filter. Not gonna be fun to change oil filter.
Opposite side showing the external DV at the OCC tee, and a manual boost controller.
Complete engine bay.
ICI pipe and framework mods needed to make it fit. The pipe clamp is to protect the pipe from rubbing against the head bolt, not to hold something together.
ICI pipe showing one of the WMI inlets --- orange elbow at bottom of the pipe. Note the pipe's "battle scar" from previous runs without framework mods.
Looks like my initial "fire-it-up" will be delayed for about a week or so. Talking with my tuner, EurotechAZ, there's been a noticeable increase in our Mini community of crankshaft center bolt working loose, causing timing failure. He's working on a fix and I'm scheduled to try it. After my last repair (this bolt and all 16 valves), I'll try most anything to prevent it loosening again.
I put lock tight blue on all critical bolts. I know it not called for but any extra insurance to help me sleep at night won't hurt. I did get the 180 degree right. The 180 on the crank wasnt as bad as the 180 on the vanos. That sure felt like I would snap it.
12-17-2018, 12:05 PM
