Sheared Cylinder Head Bolt

[leifanten]

Last night I was happily going to re-torque the head bolts with my brand new torque wrench. My 69 +2 was rebuilt 22 years ago, and been in dry storage since. I would therefore want to re-torque it before using it, as well as re-torquing after running in. This seemed like a very good idea, because all the bolts needed at least one turn to reach 62lb-ft. So far so good, just one to go..... at 59lb-ft it snapped.
It turns out that the PO has re-used the head bolts.

What was gonna be an hour work turned into a weekend worth of tearing apart and reassembling the head from the block. Not to mention the $400 or parts that I needed to get this done. The only good that came from this is that when the head came off, I could ascertain that the cylinders still have their honing marks in there, so the assumption of a 22 year fresh overhaul is correct.


Advice: if you take your head off (pun intended), replace the bolts

Leif
Houston, TX
1969 Elan +2

[alexblack13]

Hello Leif,

Greetings from a very sunny Scotland.

Can I ask, how you torqued down your head? Did you slacken them off one at a time remove and clean/lubricate and refit and torque? ''One complete turn'' sounds a bit too much, unless they were very slack! Can't remember the pitch of the thread but in must be about a mil' ..Thats a lot!

Pity you had to go the whole hog but at least you got the inspection opportunity. Not a bad idea on a car laid up for so long. Gives you a chance to change all those age wear related items. (water pump?) Good idea whilst you have the head off.

What head gasket did you use on the rebuild? I am trying to get opinion on what's best / most reliable for std road use.

Have fun! and remember. Well worth the effort!

Alex B....

[elj221c]

I would therefore want to re-torque

Why? Has anyting slackened off in 22 yeas with no running?

all the bolts needed at least one turn to reach 62lb-ft

Maybe the the new wrench is faulty?

However, methinks after 22years I would inspect and check for corrosion and such before breaking a bolt with my new wrench!

At least it didn't break within the block so that is good.

Roy
S2'65

Still on the original headbolts but always new rod bolts.

[leifanten]

Cheers guys
Well, perhaps a full turn was what it mentally felt like after I had steam coming out of my ears. And especially the one that sheared, since that kept turning without an increase in torque - which should have given me a clue as to what was wrong , but its been a while since I last did a top-off. However, there was a significant amount of torquing required for all the bolts. Its a $70 Husky wrench, and and all the others clicked nicely in at 62ft-lb (which is in the middle of the 60-65 range of the Lotus workshop manual).

I ordered a new set of bolts from RD enterprise as well as the head gasket etc. I will swap for pertronix and replace for a new electric fuel pump (relay driven) now that I have the head off. (as well as tightening the earth points underneath the inlet manifold). I also plan on sending in the carbs for overhaul to this guy http://www.paltech1.com/id2.html (any experience?)

Everything else looked very new and shiny. Like I mentioned, the honing marks where still present in the cylinders, so it has been hibernating well.

I am in the middle of putting in the RD enterprise CV joints, and am waiting for the slide pull to arrive from amazon so I can pull the diff axle stub out of the house.

If I ever get ticked about the need for "work" I remind myself that the reason that I wanted a Lotus "hobby car" was that my benz and porsche are too reliable to provide me with anything as far as hobby is concerned. They just start right up and do what they are told. The Elan is good in that regard.

Regarding method for this, and why I did it. Like I said the car has been stored dry and with oil in all departments. Everything looks like it was done last year. I.e. no corrosion. I wanted to re-torque to compensate for any "setting" of the head gasket over the course of time (in the same way that re-torquing after a few hundred miles after replacing the head gasket).

I have had the car running around the neighborhood after changing oil/filter and regular tune up, so I knew all was functioning before re-torquing.

The way I did it was by following the torquing sequence in the Lotus manual.

Any tips on mounting the RD CV joint conversion are welcome. I.e. do I have to remove the wishbone, or is it easier to split the CV joint to fit it?

cheers
Leif
sunny Houston

PS I have posted two pix of the car

[JJDraper]

Tough break...

When I first changed a head gasket on my +2, one thing lead to another and it needed new cams & valves, seats, guides etc, the guy at QED looked at the head bolts and said "these are early ones. We recommend using the later stronger ones, and even then, renew them after 3 or four uses (head on/off) as they stretch". At 12GBP each, I thought this was a little excessive at the time (and a good way to increase turnover), but paid up and got new bolts. Now I'm not so sure!

Anyone confirm the early/later comment?

Any way, it left me with the old head bolts, two which I cut down for aligning the head, as per the manual (it works a treat).

Jeremy

[512BB]

Yes Jeremy,

Can confirm both comments. Lotus started off using a waisted bolt up until i dont know when. S3/S4 i would think, and then changed to a much stronger bolt, after problems such as Leif describes. You would have to go some to snap one of the later type bolts.

Secondly, the early ones can stretch, but i have never had any problems with the bolts on my later type cars. However, one can never be certain, when working with 40 year old components, what any previous owner has subjected a part to. Unless of course, you have owned it from new.

Good luck with it Leif, and how about an update Jeremy on how your car is progressing.

Leslie {in Malvern, awaiting opening of the doors}

[alexblack13]

Beware of 'sticksion'...!! Esp with bolts that have been in place for a long time!

Allow the engine to cool (probably frozen cold already in you case Leif!!) But if the engine is hot let it cool fully. Slacken each bolt in turn in sequence. Take it out. wire brush clean the threads. Put a little lub on the threads. Then screw in and tighten to required setting. Change the bolts if in any doubt/ not sure of history but normally they should be fine.

Easy does it...

What gasket to use men ????? Whats the best?

Alex..

[types26/36]

[quote="512BB"]Yes Jeremy, Lotus started off using a waisted bolt up until i dont know when. S3/S4 i would think, and then changed to a much stronger bolt,quote]

I have seen three "style" of head bolts used on T.C. engines:
top: head with built in "washer" and only a slight waist.
middle: head without built in washer and waisted.
bottom: head with built in washer and waisted.
When I say "built in washer" I an not implying that the loose washer should not be used as well.
I was under the impression that the bottom was the later and stronger bolt but I could very well be wrong.....comments anyone?

[types26/36]

Hi Leif, looking at the pic of your broken bolt it looks like it was stretched to destruction rather than just snapping, I would defiantly check your torque wrench for correct calibration.
I have used many head bolts several times over and only once had a breakage, this was where the threads end and the bolt length starts which would be a sheer point. It was a clean break and not a stretch as yours appears to be.

[RobL7/Elan]

My input for head related hardware: 1. ARP for head bolts- they are bullet proof. Use the lube they supply when assembling. 2. PAYEN for head gasket. Best of Luck and re-check the accuracy of that new torque wrench.

Rob

[alexblack13]

Use the lube they supply when assembling. 2the ac.

See where I am coming from? Note the ref to ''Use the lub supplied''? I think it is unlikley to be the tool at fault. It is VERY important that remove, clean and lub' the bolts. You will not get the correct torque unless you do this.

If you were using new bolts and not intending replacing the head gasket, how would you do it?

Alex B....

[types26/36]

Alex is quite right about loosening the bolts first (although I don't necessarily always take them right out as they have been lubricated on installation) here is a thread outlining how I retorque the head after a rebuild:
elan-f15/more-the-same-t16527.html

p.s. Alex,I'm missing something I dont understand the "viceland link"

[alexblack13]

Sorted that.. Sorry

AB.

[alexblack13]

See above ..
ab..

[elj221c]

Leif,

I've just had a closer look at your bolt picture. I ask myself if it is of the correct type.
Compared to the three types shown later, yours appears to have no shoulder at the head end. Not a twin cam head bolt?
Maybe that is what the problem is?

Roy
'65S2