UGH

After installing a new timing chain set, resealing the oil pan, and replacing the thermostat, the car malfunctioned a half hour after starting it up!

Got the valve cover off, valves were clearly bent. Took the head to the machine shop to see what could be done, and one of the cam caps was snapped in half.

Looking for a good head to put back on and get the car rolling again, but had a few questions/concerns.

The bottom end turns over smooth as silk, but the valves, particularly on the exhaust side, left 2 dings in the top of each piston. No fragments in sight or chunks taken out of either the pistons or the valves. While some of the valves broke, none of them dropped into the cylinders. No scores on the cylinder walls.

Am i an idiot by not removing the pistons at this point to inspect for further damage? The oil was clean (brand new) when i drained it out, no chunks.

Id also appreciate any lines on a good used head. Ive got a local guy i trust to go through the head and refurbish if it needs it.

cheers!

 

Most of my used parts have been purchased through car-part.com. Great place to start looking for used parts at least, with low-ish mileage and warranties. Also, carolina machine engines is currently rebuilding my truck motor (5.7L hemi), I'm sure you could give them a call, ask for ritchie, he's a really nice guy. I don't think they have a price listed on their site for engines as new as yours, but maybe you could just get an estimate on that, or a rebuilt head, or whatever really.

 

If your valves kissed the pistons and broke you don't need another half hour motor. Check the pistons, rods, bearings, etc. Now is the time to catch ALL the problems, not just the easy to see ones. Good luck my friend. Motor on.

 

If you got a ding on top of the piston and it made a mark, it will become a hot spot if you put it back together.

 

Depends how hard they hit. Obviously the exhaust cam was out of time. As far as damage, depends how hard the valves hit. They can hit hard enough to pinch the too ring. And stop it from moving. It can also hit and cause stress cracks you can't see and when you start romping on it, boom, you just found the damage it caused. As far as the bearings, I'm sure they are just fine. They go thru a lot more abuse than that when there is detonation. Without inspecting the pistons, this is one of those calls that very hard to make on a forum. The marks can be polished out if it didn't pinch a ring.

 

I don't understand how a new timing chain can hop off the cam sprocket gear.

 

All 3 bolts need to be lose ( crank balancer, intake sprocket, exhaust sprocket ) Then install the tensioner, then tighten all three bolts. If not, when all the slack is finally removed due to rotation of the engine, the exhaust timing will be off. Exhaust valves can be damaged. Even if the tools were used.

 

And you can get new valves for your head. Just get someone to take the bent valves out. Put new in. Loosen all 3 bolts. Install the cam tools. Install the tensioner. Tighten all 3 bolts as specified.

 

On the OP's 1st post he mentions "one of the cam caps was snapped in half." I've been told by dealer mechanics I trust, that these caps are machined as part of the head and NOT interchangeable from head to head. He might luck out by trying another one, but the gamble isn't worth it --- personal opinion.

jbd5015, No comment on damaged piston disposition. However, if the you're "desperate", I have a set of used rods / pistons, etc., left over from my CP / Carrillo upgrade. My engine was in good shape when I switched them. They're available with about 60K miles --- negotiate via PM. Also, I know a guy that might have an N14 head available. I'll send him a link to this thread.

From the damage description, I'd suggest making the Bentley manual available to whoever is doing the work. Sure sounds like someone screwed up the timing.

 

I would not be too concerned about the pistons. Machined for 15 years and never heard of a "pinched" ring in a small displacement engine ( maybe a 5.5 litre v8 that broke a cam at 8k RPM). These small stemed valves will bend rather easily. How deep is the ding? 20-30 thousandths or more like a 1/16"
If the ding has raised edges, knock it down with emery so it does not act like a glow plug. Who ever said hot spot never saw pistons with valve reliefs/pockets.
At this point I would just get another head, low mileage hopefully, clean it up and install. There are so many junk yards out there.
All the best and sorry.

 

Until recently I had never heard of a cam cap on any Mini engine, but it's true and am surprised I never heard of them with all the many failures in the N14 engines. These cam caps seem like a rare occurrence.

 

Smh

 

Not sure how it happened, but like i said, the car was running beautifully for 20 to 30 minutes before the problem happened.

I cannot remove the crank sprocket from the hub. It spun in a way that damaged the hub. While the crank sprocket can spin on the hub, its not smooth, and it will not separate from the hub.

Ive been a mechanic professionally at an independent shop for about 5 years now, working on my own cars for over 10 years. Not saying that I'm a master at the trade, but i do like to think i can follow directions. I followed the AllData procedures to a T and I had an unfortunate problem arise despite that.

After talking with my machinist, he advised the same as Indimaniac and Sprintcars. The nicks in the pistons are quite small, i have all intentions of cleaning the tops off and inspecting further, but i appreciate the input!

Im on the hunt for a low mile head, or just a solid head that can be refurbished by my machinist. Oldbrokewind, i would appreciate any help I can get from a fellow Mini enthusiast. In Central PA, there arent many!!

Ill get some photos soon of the bent valves, they are pretty cool looking. I had the head cleaned and it looks very cool as it sits, so I think itll be turned into some kind of end-table or furniture!!!

Thanks for all the input guys!!

Cheers!

 

I was simply stating that he needed to do something about a ding with a raise “hump” just as you stated knocking it down so its not like a “glow plug”. I have seen and installed plenty of pistons in my time of ALL types. I was only trying to tell him to address the ding….. glow plug = hot spot different wording same meaning

maybe one day I will learn to just shut up .....

 

No worries, the internet can be a tough place to voice direction or tips. The unfortunate problem with text is that people can interpret information in different ways!

thanks again for all the help guys! Hoping to have the Brownote back together by the end of the month!!

 

How did you set your timing, did you use the rigid tensioner?

 

I can't comment on the AllData procedures --- don't know how they compare to Bentley's. Main thing is to use ALL the correct special tools --- flywheel lock, cam locks, & chain tensioner. And, as Sprintcars says, chain sprockets gotta be loose BEFORE setting the tensioner, THEN tightened. Bentley also ID's the "stretch" or "TTY" bolts, and torque sequence / specs. I'm not a pro mechanic, but I found some of the torque specs "different" from previous experiences --- "additional 90 degree turn", etc.

Now that you're getting another head, if the fuel injectors aren't already installed, that's another special tool, to remove / install FI seals.

Best of luck with the next head.

 

I figured there would be a few more tools to get with the fuel injection system. This was the 2nd timing chain job that i did, the first one for a customers car and it went swimmingly! Figures my car would get messed up.

 

You can take your head to the dealer and they can install new injector seals for a fee, the special tool isn't readily available.

 

Ah the joys of living 150 miles from the closest MINI dealer...

 

I couldn't imagine being that far from a dealer, I'm under 5 minutes next exit from a dealer, there are more within 10-15 miles.

 

We've got a BMW dealer, perhaps they use similar tools for the DI 6 cylinders? Ill give them a ring to see if they can assist.

found a head in the southeast for a good price. a pull off from a running motor, no full rebuild needed, but ill probably just have it cleaned and checked and valve job/seals done regardless. All this work is worth it for how far apart this thing is!

cheers!

 

WOW!! What an ordeal.

After getting a salvage head, ordering all the parts from MINI, sending off parts to MINI for the injector rail seals, machine shop time, life in general, etc etc...

I got the car back together this weekend! I can only work on the car on the weekends for about 4 hours at a shot, so it took about 10 hours to reassemble, taking my grand old time.

Ill get some photos up soon. The car is running tip top. I just cleaned up the tops of the pistons and 'wizzed' the impact spots from the old valves. The head rebuild came out BEAUTIFULLY. He had to resurface the head by about .010" so it matched up real nice. All new valve seals and a valve grind.

Overall a great learning experience for me on how these cars go together. Its running very well so far, and very quiet. My old tensioner was actually BROKEN. Amazing it didnt cause any damage.

cheers!

 

Excellent news, you're saying a small fortune is labor installing the head on your own. 10 hours (4 hours per) to reassemble is better than rushing the install of the head, looking forward to pictures of the bent valves and all other pictures!

Didn't know that these OEM sodium filled valves as brittle as they are can bend, I'd think they would break like glass.

 

Glad to hear that your mini is prowling the streets once again! Since you have just done your head, I have a question for you regarding the valve stem seals. Did you need a special tool to remove them or would a set of needle nose vice grips get the job done?

I see these special tools available but they don't appear to be anything special, perhaps just nice to have?

http://cdn.shopify.com/s/files/1/021...g?v=1363205722