Wayne-head stud question
 

I've used mapp/oxy on my head studs for removal. Most came out but a few are being very stubborn. I've used the correct tecnique -steady flame just inside the case where the sud goes in to heat the case before the stud - and went through 2 1/2 bottles of oxygen (25-30 mins) and it didn't budge, My Q is I didn't try your canned air trick. DO you think that should be my next step or just go straight to O/A the way many pelicans have reccomended?

There are many opinions on this. If you have access to the O/A torch, and know how to use it, then go to town. It can be a dangerous tool if you don't have experience with it.

There's no right or wrong answer on this one - the canned air trick worked for me, when I was using a relatively low-heat propane torche...

-Wayne

I've sent cases to Rimco (Riddle Machine Co.) in southern california to have studs removed. They have them wire EDM'ed out of the case, usually without damaging the case. I've only had one single case that needed one single timesert needed to correct the case.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

Mark,

I can help you get those remaining studs out when I get back from Italy on May 28th. Won't one of these rent-a-tool outfits rent you an Oxy/Acet torch? I think you only have to go to the EDM solution if the studs break off flush with the case and you can't get a grip on them...which isn't your scenario.

Someone from the local dorkiphus board is lending me his!!

Is this harder on Al cases? I've never needed more than 30 seconds per stud with propane on Mg cases.

it's not uncommon to have a few holdouts that need a lot more heat than the rest. use a robust flame, not a little tiny one. i've never melted a case yet with oxy/acet. just don't get the white part of the flame too close to the case.

Yes, magnesium is much softer than aluminum, so the problems that people have here are typically related to aluminum cases. Many mag cases will let their studs go without the addition of heat. The aluminum is another story. When combined with the brittle Dilavar studs, getting them out can be a huge pain (see Project 95 in 101 Projects)...

-Wayne

Plus, a mag case can turn into a ball of fire with the help of O/A!

let's hear it from all of those who's mag case flamed on. i think you're overly worried about this.

I haven't heard of any (probably because it was never needed, except for exhaust work) but I have heard of interesting brake tales, etc. from other car nuts. Magnesium is combustable, that's the only reason I mentioned it.

Get a bigger hammer
 

Believe it or not a good swift shot with a brass hammer will shock the threads and cause any rust or loctite a that is holding the stud in place. A touch of heat and you win. In twenty five years I have never seen an unbroken stud that would not come out with impact and heat.

Spent a lot of time hitting them with a framing hammer at the same time they were being heated! These buggers are simply stubborn!

Yea....try to set one on fire, this seperates the those who repeat rumors from those who been there....I guarntee it will not catch!

Why is everyone so intent on getting these studs out? My case (mag) had all there studs firmly in place when I did my rebuild. It seemed just plain foolish to remove them at all! The rebuild was not effecded in any way by not removing and replacing them, with or without case inserts. How is it that this mantra of religiousl removing and reinstall these studs got started. My rebuild is almost complete and EVERYTHING is going back in place without any interference in any of the parts. The case didn't require extensive maching since I measured anc checked everything.

Just my thoughts since reading here no one has voiced any opposition to this "always remove the head studs".

Sayah,

Only time will tell if you pull a head stud in the next 1000 miles. The odds are just to high that they will after the engine has been disturbed in a rebuild. You might be OK, but the repercussions are rather high if they do pull.

JP

Out of curiousity, what year was the motor and have you put the crank back in the motor yet (and does it spin easily)?
thanks,
Chris

The only reason is pc. of mind. Alot ezer on the bench then in the car (which means back to the bench)

If you're case is a 2.7, and it doesn't have case savers, or time-certs, I'd say there's a near 100% chance that your head studs will pull within the first 1000 or so miles.

You might want to get a copy of my book: http://www.101projects.com. - all of the reasons why you should replace your head studs (or reinforce them, as is the case with the magnesium blocks) are detailed in there.

Your statement is akin to saying "why shouldn't I wear a seat belt? I don't feel like I'm flying out of my car through the windshield right now?"

:)

-Wayne

Chris, the engine is a 69E. Not only does the crankshaft turn over easily but case halves went together perfectly, the heads bolted up without a hitch and the cams have been aligned and were not off at all from what originally was set.

This engine had problems when I first got it (2 blown head gaskets) BUT NOTHING DRAMATIC! ( like most of the problems porsche engines are reported to suffer from). In addition the previouly rebuild omitted the o-rings on all the case through studs.

My advise is:

1. Do an autopsy on your present engine. Don't just blindly replace everything if it is in spec and never, never just replace head studs if they are firmly in place and seem OK. Don't maching case halves unless they need it. Don't mess with things that work.

That's great Sayah (that you didn't have to fix the case). Anecdotally, the 2.7's seem to be the ones I hear about having twisted cases. Maybe that's because there are more of them?

Perhaps the mild horsepower of the "2.0E" has mitigated the tendency to pull studs in your motor? For your sake I sure hope your are able to tell us "Nyah, Nyah" after a 1000 miles. :D I would suggest avoiding situations that get the motor really hot i.e. 90 degree stop and go traffic. I've got my fingers crossed for you.

You mentioned that the motor had a couple of "blown head gaskets". What was the cause of that? Were some head studs loose enough to let the head lift off and flame cut the head sealing surface perhaps?

Normally, one measures and just replaces the parts that are out of spec. I don't think anyone will disagree with you on the point. The head studs are a different animal though. You can't tell if they are good just by examining them. On a mag case, it isn't the head stud that you are really worried about, it's the case around the head stud threads. The "address the case stud" mantra has been arrived at by hundreds (thousands?) of people figuratively being struck by lightening after assembling mag case motors with "good looking" head studs. They drive a few hundred happy miles with their rebuilt motor thinking that the storm has passed and then "Zap!".
-Chris

Well Chris I hope this doesn't happen also. I put in hour and hours (happily) and broke a few parts in the process to get where the engine is about ready to go back in the car. Spent about 1500.00 and in the process took the transmission apart to inspect and replace any obvious worn parts.

The head gaskets blew because the studs and nuts lost their torque. The chain drive train was pretty worn. The mech chain tensioners were just barely holding on. My engine exibited NONE of the more dramatic and costly symptoms people talk about on this news group all the time. Everyting was quite prosaic, worn parts, missing gaskets, when the last overhaul was performed, thus causing leaking and smoking. I managed to get a set of used "e" pistons, which were in better shape than mine, re-ringed them, put in a newer oil pump, new bearings, a new valve. Right now I'm waiting for my machinest to bush my idler sprockets.

The reassembly has been just so smooth, the engine without any case work, except for the oil bypass modification has bolted up like butter. Squeezout is uniform. My guess is that when I finish the whole thing will most likely give years of trouble and hopefully leak-free service.

The UPS man is convinced that this is all therapy for me but I keep insisting that its just to get a great running sexy car for a low price.

long before i knew about this site and waynes book i thought id rebuild my'75 2.7 mag case engine. two studs had pulled , so i helicoiled the two damaged ones (yes i know-HELICOILS????) and replaced all the studs with new dilavar studs (yes i know-DILAVAR????). 200 miles down the road and id pulled some more on the other side. I probably wouldn't have junked the motor and started throwing HIDEOUS amounts of money at a 400hp 930 engine build if id have read the book, spoke to blokes at this place and dunit proppa the first time round! (having said that, the down side to doing the 2.7 proppa would have meant that i wouldn't have my 400hp 930 engine so, in hindsight, thank god they pulled!

studs out yet?
 

Mark,

Did you finally get all those Dilavar exhaust side studs out? Is the rebuild progressing?

Doug

bump

Doug, Just borrowed an O/A set up from a local P-head and have to buy an adaptor to make the tanks work. Hopefully this weekend will prove fruitfull!

Mark, I have to pick up my MAPP gas stuff... I am taking off my exhaust. What day this weekend is good for you? Maybe I could help you with the Oxy technique. You pound, I't ll heat it.

Doug

Sayah,

I completely agree with you on the case struds. Your engine is a 69E , and if the struds are firmly in the case, there is no need to put time-serts or case savers in it. This is the experience of the italian workshop where I had recently rebuild my engines.
On my case we put in time-serts (because it is 2.7 now) , and it took hours of heating, oiling, etc. to get the struds out. You twist the strud by 90 degrees, but it will not come out. So also in a MAG case the struds can be well fixed!!

Andreas

Sounds good Doug. We will have to get in touch late Friday to see if Sat or Sun is better. Not sure now. Let's hope that the O/A does the trick!

Mark, I think the Oxy/Act will do the trick. Give me a call when you know more about day/time. 301-596-0407 or cell at 410-262-1574.

Doug

did it work, the suspense is killing me?

All but one. That one I will be trying Wayne's canned air trick. We spent over 1/2 hour w/ constant heat. NO KIDDING! Beyond stubborn! Anyway, I hope we haven't dammaged anything. I don't think so but am a little worried.

Last night we had success! My GF and I spent 1 1/2 hours on that last stubborn stud. Here is the successful technique - heat w/ OA for 1/2 an hour and keep heating, hit with a hammer until your hand hurts, use 2 very good pairs of locking pliers, use a liberal amount of Wayne's canned air trick and the kicker, use a jerking motion (like and impact tool) to mover the pliers. I spent 3/4 of an hour, once it began to move to finish pulling it. The biggest PIMA in my life bar none!!!!

Mark, congrats. Sounds like your GF should be your helper in future projects. When I was helping you, it wouldn't budge. Now that you got that out of the way, any more obstacles to reassembling? If you need help in hanging the engine back in, I am willing and somewhat able.

Thanks Doug! No, you did fine, I just had the cold air and the impact notion. I was simply more stubborn than it was, I guess. I wonder if 3 hours on a single stud is some form of record and if so, do I really want to hold it?

Take care!