Thread: S1 Holden 186 smoke issues

Identical to the one I have, except mine is a bit rusty (was that waay when I bought it at a clearing sale 25 years ago!)

1. here is a comparison of where the two bolts snapped to give me an indication of whats left in the block to extract, at a loss for the first one, but the 2nd one i can still manage to secure a nut on top of the extrusion and will give welding another go. fill with weld then hopefully undo the nut and the bolt should come out. not sure but are these bolts hardened steel and thus harder to weld? normal length on left.

2. more cleaning has yielded better results including piston tops but needs more towards the rear to clean up for good. If only I could get those damn two bolts out I will be done.

As for the mobile mechanic no go, people seem not interested which means more work for me, oh well. As for the clamp will need to see if i can bend it back with some heat I think its made of aluminium.

by the way can I sparingly use a razor to clean the top of the block for those really stubborn left over gasket?

can I go ahead and purchase the piston rings standard size or should i hold off till i get one piston out before ordering please

Being a retired engineering tradesperson , I would not advise you to go any further trying to remove your broken studs.

To me it would not be a challenge but to an inexperienced person could lead to tears.

Surely someone experienced lives close enough to assist you?

Maybe as you suggested using an indy mechanic (who has experience removing broken studs) may be your best solution.

Best of luck with it.

1. heat and bend - first attempt not too bad but slightly off so heated and attempted twice
2. my heat source and steel bar to help bend the U into a U
3. as close as i can get it, both arms level now, so hopefully can remove those damn valves guides soon as
4. prior to reading some comments (ramblingboy) I did have another go at welding a nut on, nut to one side of pic but it did not work
5. underside of nut after welding, weld for some reason is not holding or the bolt is real stubborn
6. there is the stubborn bolt - might call in an expert bolt remover if i can find someone local
7-8. as clean as i can get these, job done with cleaning the block pretty happy with the outcome and has transformed the engine I feel

well it happened didn't it, as possibly predicted by some....

called my local bolt shop for a contact for a bolt remover specialist - didn't know of one, couldn't find any locally, I am sure they are out there but couldn't find any. another indie mechanic was going to send a number through to me but never did so.... the local bolt shop said they had some reversing drills and drill bits to remove so went down to look and see

1. so bought these very good quality for almost $100 for the pair

2. put to use could feel it was tight so kept drilling out to make less of the snapped bolt in place, then applied heat directly in the hole and this happened, snapped again would not budge, bugger (extractor stuck inside not the drill bit)

3. so decision made to toss the engine and find a replacement one, bonnet off and accessories coming off, recently another holden 186 was selling cheap enough so will need to look around something i can hear running and confirm no smoking so no need to do rings but open to what's available locally. I will need to source an engine lift as the diff is in the way of removing from below as i did b4.

4. in its current state, hoping to rip the engine out asap, but looking for alternatives now, workload increased ten fold now

Joe , if you are pulling it out why don't you take to engine re - conditioner see what they can do . they would have dealt with broken studs & should be able to give a report on engine condition & a quote on what is needed. Buying second hand you don't know what you are getting . I know people who have bought an engine on seller saying it has been re-conditioner only to find all that has been done is new rings & bearings in a worn out motor which soon becomes a problem & they have no come back.

Also that type of tapered stud extractor all they do is expand the stud making it tighter in the thread & this is usually what happens with extremely tight studs , they are OK for bolts that are not very tight . They should sold you a straight shanked extractor like the one I posted earlier, that don't expand the bolt in the hole.

What the engine shop will do is Drill the bolt with procession drilling machine then re-tap the thread providing you have not damaged it . Then they may be able to helicoil it were they tap another thread in then fit a helicoil that will be correct thread for the studs .

Bugger - as you’ve found out, removing broken bolts can be very difficult. With something like that I would have stripped the block down and put it on a mill to drill the holes out precisely based on the actual measurements of the block then helicoiled the new hole.

Could still be salvageable and if you’re pulling the engine anyway, someone may be able to do this.

Some of the head studs in a Holden straight six go directly into the water jacket and require a special AC Delco (or a similar alternative) thread sealing compound, to stop water/coolant migration up the thread. It's a pricey product, so for the guy doing a one off engine rebuild, its often not an option, so blokes tend to use an alternative.

Given the drama's you are having with those broken studs, my guess is some dill might have opted for Loctite as a sealer when they rebuilt your engine. If by chance this is the case and it's one of the high end Loctite products that has been used, you will need to heat that stud up to red hot in an attempt the break the adhesion.
The other option is precision drilling, then helicoiling a new thread into the hole, but as Homestar say's, that's best done on with a some accurate workshop machinery like a mill drill or similar.
As a last ditch attempt if there is enough of the broken stud remover sticking out you could try putting another nut over it and getting some decent weld onto it so it will hold, plus the intense heat might crack the seal. But be careful, you dont want to bugger the block.

With regards to the valve stem seals you can use the standard little neoprene rings, or you can get the ends of the valve guides machined to take the mushroom type valve guide sealing caps. Not necessary, but i recently had this done to one of the Holden engines i rebuilt, and i would probably do it again.

If you stick with this engine and decide to hone the cylinders, remember honing isnt just about deglazing the bore, its very important to get the correct cross-hatch pattern on the cylinder walls. So if you bugger this up, your engine will blow loads of smoke, will use oil, and may take forever and a day to before it is run in, and stops using oil.

To answer your question about the pushrods, they are necessary because the engine does not have an overhead cam, they are the mechanical link between the cam lobes and the valve rocker arms.
The lifters can be pulled apart easily and cleaned out, its not a hard job to do. You can buy new ones through Bursons or Repco etc, about $38 for a box of six (you need 12) last time i purchased them, but that was about three to four years ago.
I just checked Ebay..$60 for six, and Crow Cams list them on Ebay for $133 for full set of 12.

The 186 are a good old donk, and once sorted, it will give you reliable and trouble free running for years to come.


Cheers, Mick.