Evo X upgrades - Page 21

**Kracka** · 03-23-2010

If nothing else I'm sure some shop would be willing to purchase the head to use as a porting template.

**mlomker** · 03-23-2010

Well, that head is the property of DB. If they can find a way to fix it up and/or make a few bucks on it somehow then that'd be awesome. I just wouldn't care to have a patched-up head in my car...and Shane didn't want to put it back into my car, either.

**mlomker** · 03-23-2010

Cam cap has a boo-boo:

I like how the engine bay is going to look.

Matt D. · 03-23-2010

Quote:

Originally Posted by mlomker

Cam cap has a boo-boo:

That's seriously fucked up. I don't follow EvoX news, but has anyone anywhere reported a problem like this, even a dealer doing something on the head and having this happen?

**mlomker** · 03-23-2010

Quote:

Originally Posted by Matt D.

That's seriously fucked up. I don't follow EvoX news, but has anyone anywhere reported a problem like this, even a dealer doing something on the head and having this happen?

I'm so not a mechanic but the guys at DB said they immediately searched the Internet and found 2 or 3 similar instances. My bit of research suggests that the cam caps are custom machined for each head. It is to compensate for machining tolerances in the head itself. If the cap is torqued down even the slightest bit out of alignment then the cam will bind and break the cap.

I posted a thread on EvoXforums and I've gotten some feedback already. The immediate comment was that you have to use dowels to hold the cap in place while torquing it down and that the specs on those bolts are in in/lbs and you have to use a very good torque wrench. I obviously wasn't there when Shane did that work so I'm not going to speculate.

It's an "upgrade opportunity" as far as I'm concerned. There are a number of people on the EvoX forum that want to buy the head from DB and have a machine shop fix it. They seem to think that'll be fine. The tolerances sound rather tight to me. I dunno.

Matt D. · 03-23-2010

Quote:

Originally Posted by mlomker

I'm so not a mechanic but the guys at DB said they immediately searched the Internet and found 2 or 3 similar instances. My bit of research suggests that the cam caps are custom machined for each head. It is to compensate for machining tolerances in the head itself. If the cap is torqued down even the slightest bit out of alignment then the cam will bind and break the cap.

I posted a thread on EvoXforums and I've gotten some feedback already. The immediate comment was that you have to use dowels to hold the cap in place while torquing it down and that the specs on those bolts are in in/lbs and you have to use a very good torque wrench. I obviously wasn't there when Shane did that work so I'm not going to speculate.

It's an "upgrade opportunity" as far as I'm concerned. There are a number of people on the EvoX forum that want to buy the head from DB and have a machine shop fix it. They seem to think that'll be fine. The tolerances sound rather tight to me. I dunno.

That is the first head I've seen having a cap that goes over both cams. Other Mitsubishi heads (4G63) have separate caps for each cam.

I can see where if the cap isn't seated correctly before tightening, or if the cam puts pressure upward on the cap when it gets tightened, that the cap could break like that. Though how it would break when the engine is turned over doesn't make sense.

Best of luck, we'll be looking forward to seeing what you end up doing.

**mlomker** · 03-23-2010

Quote:

Originally Posted by Matt D.

That is the first head I've seen having a cap that goes over both cams. Other Mitsubishi heads (4G63) have separate caps for each cam.

Totally. This is new with the 4B11T.

I got a bit of good news tonight. A guy that does R&D work for Cosworth saw my post and offered me a head for $3800. I seriously doubt that I could beat that--it looks like $4200 is the going price.

Quote:

Originally Posted by Matt D.

Though how it would break when the engine is turned over doesn't make sense.

It may very well have broke while he was torquing it down. I am smart enough to not ask a lot of questions after someone offers to fix an expensive problem. I could tell he was kicking himself enough already.

**Murlo26** · 03-23-2010

It looks cool at least

Kevin 1G Drummer · 03-23-2010

Wow, I've never heard of a cam cap breaking like that. Any idea why it happened?

**goodhart** · 03-23-2010

That's pretty gay about the cam cap peice.

turbotalon1g · 03-23-2010

fucked up, good thing you are balla' though. lol

sorry to hear but glad you are making some good out of a sticky situation.

**mlomker** · 03-23-2010

Quote:

Originally Posted by turbotalon1g

fucked up, good thing you are balla' though. lol

I'm not sure that maxing out my car loan is balla'. I guess I'm just willing to spend what I don't have at this point.

It's become a 'moral imperative' to see this project completed. lol.

Kevin 1G Drummer · 03-23-2010

I suppose the cap could be welded back together then machined to fit again, but I'd be a little hesitant to use a cam cap like that.

Constant_Project21 · 03-23-2010

That's nuts, crazy it broke. The engine bay looks way better with all those covers off.

**Shane@DBPerformance** · 03-23-2010

It happened while taking off/putting on that double cam cap, while working on setting up his valve clearances. The Evo X doesn't have hydraulic lifters, it uses non-adjustable valve tappets that need to checked/measured/bought/etc that go between the cam and valve. I had 3 that weren't within the specs with his new cams in there.

There is a bearing on the cam cap where it broke. Only 1 cam journal in the head uses a bearing and it was the one that broke. I am sure not if a dowel wasn't seated correctly or the bearing was a little out of alignment/high/rotated and it caught an edge. It took very little force for it to break. I didn't realize it was such a potential risk for breakage until after I did it and found other people on EvoM who had done it also and heard from Brookdale Mitsu that they have had other customers in town do it also. Since there is a bearing in the one that did break, I have a solution for fixing it, that I would do if it was my car, but it's a customer car and I didn't want to do that on his head or fix in that without telling him. The look of the casting and thickness of cap in that area doesn't scream strong, it looks like something you could tap on the ground and expect it to snap off.

**Murlo26** · 03-23-2010

Well I guess more research for when you pull my head

You didn't have to deal with this when doing my cams did you? I am guessing because you didn't have to pull my head...i am no mechanic.

**Shane@DBPerformance** · 03-24-2010

I had that piece off your head to do the cams, but I didn't have to mess around with yours as much taking things on and off, because all of your valve clearances seemed to be within spec. All of his clearances that were out of spec were on the exhaust cam, 2 were barely out of spec and 1 was a bit farther out. You won't have any rockers popping off or lifters collapsing with these heads, but dealing with shim buckets is sometimes a pain and can get expensive. I have done Subaru and Supra heads with BC cams that required every shim bucket to either be moved from another valve or replacement ones bought. Buying the cheaper cams ends up costing more than just buying some HKS cams that are ground right in the first place, but a lot of guys will also just drop whatever in without ever measuring anything.

Quote:

Originally Posted by Murlo26

Well I guess more research for when you pull my head

You didn't have to deal with this when doing my cams did you? I am guessing because you didn't have to pull my head...i am no mechanic.

Swifty1638 · 03-23-2010

Toyota uses this type of design on some of those heads too, but they are more robust and better designed then these are.

Swifty1638 · 03-24-2010

I HATE doing the shims on those buckets!! Luckily the dealerships paid us a few hours book time to do them!

Matt D. · 03-24-2010

Regardless, your car is in good hands. This is why DB rocks and Shane is the man.

Thanks for the info, Shane.