History repeats itself. The turbo car is broken again and will be for a while..

Once again...

The tapered hex head cap screw that holds the frontmost part of the rocker conversion kit to the head broke off flush with the head. The plate steel where the rocker studs screw in bent and allowed enough play the the rocker swiveled off of the pushrod.. To top that off, one of the hex head tapered bolts that secures the plate to the head stripped while trying to remove it.. Locktite.....

So, now I have a stripped bolt and a broken bolt in a head that is probably easier to remove by pulling the engine out.. To top that off I will need to come up with a way to secure this plate to the head in a stronger fashion than just these bolts.. And I will need to do both sides. Guess it's parked for a while... That's a big mess..

Not sure what I'm going to do at this point. Last time this happened it was in a different place. I went out sourced some high quality fasteners and JB welded everything together. It's been working like that for some time now.. It isn't coming apart without removing the heads and drilling the heads off of these fasteners, and then hopefully putting vise grips on the 3/8 piece of screw still sticking up.

I'll have to see about either welding the plate to the head.. Drilling and tapping a bigger hole for a larger fastener maybe?? Not sure..

I haven't decided if it's easier to pull the engine or do it in the car either..

What a mess..

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Here's what it looked like last time. The rockers, studs and valve tips all look good. And they are just old used stock springs. Nothing high pressure..

 

Sad news! Welcome to 350 R&D. Looking forward to see what your fix is.

 

sorry to hear Jay. Hang in there, if it was easy, everybody would be doing it.

 

Any ideas why these are bending? I just picked up my heads last month with this kit installed. Still on the shelf waiting for the next phase of the engine build.

What ratio rockers are you running Jay?

 

Is there any room to weld a short vertical bar along the top of the plate to resist bending upwards? Broken bolts always suck.

 

Yes.. It bends because the bolt breaks.. 1.6 rockers.. Maybe there is just so much cylinder pressure when the exhaust valve goes to open???

 

The plate is plenty strong. It's attachment to the head is not. THe question is, can this plate steel be welded to cast iron head???

 

Mixing metals on welding isn't impossible but it's usually not very good and nearly impossible to find someone skilled in doing so. The engine mount pads for the 455 are cast iron, my Dad paid a professional welder to weld them to the steel cross member, when I pulled the engine a few months later one of them had all the welds fail and fell off when I lifted the engine. I bolted them in proper then.


I like the idea of drilling the holes larger and heli-coiling a larger thread in there if you have enough material around the the bolt. Bolts get substantially stronger with each size increase.

 

Sorry to hear of your troubles. I would have to think that the bolts must have loosened up and then all the carnage. I am thinking that most likely everything would be fine if you had used blue locktite in the first place. Not trying to make you feel bad, just my guess on what happened.

I agree that drilling it out, adding a helicoil and larger bolt may be the answer at this point.

 

I am also thinking you must have extreme valve float using stock valve springs with the turbos... This may have been a factor.

 

Oh.. They were Blue Loctited alright.. Just like last time. I'll be lucky to get them all out again. Not only did they have loctite, but the whole mounting surface was covered with JB weld which partially worked its' way into the threads as well.. The blue locktite is so strong that the fastener cannot be removed with the Allen key hole. It won't unscrew. It just rounds out even being as careful as I can..

 

??? How would I ever know the answer to this??? It runs pretty good..

 

All I know is what I read in the turbo books and what I have heard... The theory is that the turbos put extra force on the valvesprings compared to running NA. I know that even NA the stock valve springs suck....

 

Sorry to hear the news. Best of luck!


Scott

 

Sorry to hear this Jay. Guess when I get my done, it'll have many of the same problems?! Oh well that's what happens with us SPEED freaks, " Fast is NEVER FAST ENOUGH.

 

This sucks.. It will never be ready for the turbo buick Nationals 20 miles away on May 14th..

 

Can you use heat to get the locktite loosened up?

 

The problem is supposed to be that the intake valve can't close under boost, and ignition takes place with the valve open..

 

if you had a higher spring pressure it could close i would think