88' shelby Z quest for 11's (lots of pics)

[ShelGame]

The TIII is on the manifold, but under. The Neon is on the block. The SOHC engines are higher up,bon the top side if the intake Mani.

My point was, the knock threshold isn't as dependant on the mounting as it is the bore and block structure, so long as the mount is rigid.

[moparzrule]

I think as long as the BMF mount is very rigid, it will give similar results as stock. Look at the TIII and Neon knock thresholds, very different knock sensor mounting, but similar curves. Its really just fine tuning.

It definitely is rigid. The concern was resonation due to it being a thinner piece of aluminum, but it's literally only like 1.25'' long between the runner blocks and that mount is fully tig welded on. I honestly think it's fine, and only a tiny bit more sensitive than stock. But I will make sure with the det can.

[Vigo]

The TIII is on the manifold, but under.

Ahh, my lack of TIII ownership bites again. I'm gonna have to pick one up just so i don't sound like a newb every time the subject comes up.

[88C/S]

Any clearance issues between the BMF and the header. I ran into one test fitting the BMF and an extra header I bought.

[moparzrule]

Yeah, pics and details are in the first post.

[moparzrule]

So I was just cruising along yesterday, was out to do some tuning but I was just warming the engine up first. So I was just leisurely cruising when all of the sudden the engine starts chugging hard and not running on all 4. So I pull over quick and shut it down. Made sure it didn't skip some teeth on the timing belt so I turned it around to TDC and confirmed cam was correct and distributor was correct.
So I had one more sneaky suspicion since it happened to me before a long time ago, though never while cruising down the road. So I pop the valve cover off, sure enough a rocker had fallen off AND the bad part.....the valve was stuck down. Dropped valve seat, yippie. So I did what I did last time, set the rocker back and cranked the engine with the coil unplugged, one revolution popped it back up. Bolted the cover on, drove it back home...thankfully I wasn't but a couple miles down the road.

I don't even know what to think other than I need to possibly find a new machine shop or this car/engine is cursed. I've never put so much money into a turbo dodge, and never had so many problems that I'm not even causing. Honestly I'm pretty depressed about it, feeling like parting this thing out right now or getting a few sticks of dynomite. Getting tired of throwing money at it and not getting anything but headache in return.

[going4speed]

I feel your pain brother! I have a car in the garage I have $5k in and I've never driven it. Ever!

[moparzrule]

OK so finally had time to pull the head today and investigate. Turns out the seat did not drop, the valve is just kind of frozen inside the guide. I was able to move it but it's extremely stiff and barely moves at all. I only removed the spring on the one intake valve that was stuck open so I don't know yet if the other valves are stiff as well.

I don't know if the valve bent, or the guide is defective in some way? Not sure but these are brand new iron guides that were just installed and the valves were brand new MP +1mm valves. UNLESS, the seat did drop and it bent the valve the one time when it got stuck. I guess that would be possible. I'm pretty much going to take this back to my machine shop and ask them whats up with it.

[Reaper1]

Might not have the right stem to guide clearance. Galled the stem and the guide and caused it to get stuck? Just a theory. Also, check the stem seals. I have a friend of mine that has said he's seen premature wear on engines that used positive locking seals when they were originally designed for umbrella seals. I don't know what you are using, but I thought I'd throw that out there.

[moparzrule]

Well I had the machine shop acquire the guides and assemble the head, I hope they were competent enough to check that but maybe not. I supplied them with the mopar performance Viton valve seals to install on them, so as long as they actually used them (I didn't get charged for any so I assume they did) it should be fine.

[2POINT5TURBO]

I really hope you can get these things sorted out, good to catch them now than suffer catastrophic failure later, I'm really rooting for you here. Nice to see another Shelby D going for 11's other than myself.

[Force Fed Mopar]

OK so finally had time to pull the head today and investigate. Turns out the seat did not drop, the valve is just kind of frozen inside the guide. I was able to move it but it's extremely stiff and barely moves at all. I only removed the spring on the one intake valve that was stuck open so I don't know yet if the other valves are stiff as well.

I don't know if the valve bent, or the guide is defective in some way? Not sure but these are brand new iron guides that were just installed and the valves were brand new MP +1mm valves. UNLESS, the seat did drop and it bent the valve the one time when it got stuck. I guess that would be possible. I'm pretty much going to take this back to my machine shop and ask them whats up with it.

I have a Daytona here with the same exact situation, brand new head but the car has sat up for 4-5 years and now the valves are sticking in the guides. Gonna have to pull the head and have it checked out, already tried spraying penetration fluid and carb spray on the stems to clean/lubricate, no help.

[Ondonti]

I have a Daytona here with the same exact situation, brand new head but the car has sat up for 4-5 years and now the valves are sticking in the guides. Gonna have to pull the head and have it checked out, already tried spraying penetration fluid and carb spray on the stems to clean/lubricate, no help.

The guide hones I have seen are incredibly accurate so even if the bore and clearance was spot on, a tiny bend would cause failure. That or unlucky galling (FOD or previous damage/tool marks) as mentioned by reaper1.

[moparzrule]

Picked up the head from the machine shop today. They said, possibly because of the aftermarket valves, they needed more clearance in the guide. They originally set the clearance to the minimum spec, but now it's closer to max spec to make sure I don't have any more issues. The good news is they said nothing was damaged and the other good news is they didn't charge me anything lol.

[GLHNSLHT2]

nice.

[lengel]

Glad to hear! Going to make it to Cecil?

[moparzrule]

Possibly, not 100% sure yet.

[Vigo]

So what is this cracked oil galley thing about?

[moparzrule]

It ripped out the bearings again in under 300 miles so I pulled it out again and popped the galley plugs myself this time. The oil galley actually has a small crack, apparently dumping off oil pressure and starving the bearings at anything over 5k RPM.

I bought another block, but I have to get it all machined again $$$$$$, but I'm finding a new machine obviously since they apparently didn't check the galley for cracks both times I had the block cleaned. This cost me well over a grand in machine work on that block, getting the rods remanned, buying a new crank, and not to mention all the headache of removing and replacing this engine 3 times now. There's apparently no good machine shop around here, going to have to go atleast an hour away for a decent one probably because I've tried them all within 45 minutes so far. I don't know how any of them stay in business.

[Vigo]

Post a pic of the crack when you get a chance. I've been opening up the oil galleys on 8v blocks i've been building for the first time recently so it may be useful for me to know how yours failed.