Helicoil kit for Inlet Manifold

[Bassy]

I pulled the inlet manifold off to get the waterpump out on saturday. I was expecting a mare getting the pump out but it came out ok thankfully, and the impeller has gone off to get machined. It was quite badly pitted so was worth doing, and Im fairly sure this is where it was leaking from

Ive turned my attention to the inlet manifold and can see 9 of the 12 threads for the bolts have been coiled already. The ones that havn't look right iffy though so I thought I may as well do them whilst in the area so to speak. I found this kit online
http://www.chronos.ltd.uk/acatalog/I...PAIR_KITS.html I need the 5/16 UNC one I believe?

However it seems quite cheap compared to others Ive seen. Ive never attempted a helicoil before. So the question is I suppose do I spend more money on a named kit , and if so recommendations? Or will this do the job?

Also any top tips to stop me screwing it up?

thks

Andy

[Staggard]

I am not an expert on this, but the way I see it its the coil that does the work and theres everything in the kit to fit them. Graham

[jleyton]

Hi Andy,

Chronos are a good supplier and that's the kit (which I got from Chronos) I've used without problems, so I am happy to recommend it from my experience.

When I first Helicoiled I was very apprehensive but it was easier than I'd have ever hoped. The important thing is, when you're drilling the hole, to keep the drill at right angles to the head. However, if those holes are looking a bit ropey then you may be able to go in straight away with the tap (very carefully, backing it off often and lubricating the tap) without drilling. Just be very careful and if you find it's hard work with the tap then you'll need to drill first, but if you don't need to drill then you do away with the risk of the hole going off line.

Good luck - it's a great feeling when Helicoils work properly (I found it almost addictive )

Cheers

Julian

[scraggs]

Do not spend big money on Helicoil kits. The kit you are looking at is ok. It needs to have a tap, a drill, tool, and Helicoils of a given thread dia, ie 8mm, or 5/16 etc. It is really easy to do as long as you take your time and what ever you do you MUST put a lubricant on the tap if not it will tear at the aluminium. One other thing for a good thread is when you are cutting is to cut 1/2 a turn then back 1/4 and so on.

[Nambo]

I think for any given tap, a smaller drill is recommended for alloy than is recommended for steel, or maybe I just imagined that?, if so however, ensure you are using the smaller drill so that the softer alloy will have more meat on its threads.

[GDPR]

Can I just say.... CAREFUL HOW DEEP YOU DRILL!!!!

Mark the drill with tape to the original hole depth.....

[jleyton]

I think for any given tap, a smaller drill is recommended for alloy than is recommended for steel, or maybe I just imagined that?, if so however, ensure you are using the smaller drill so that the softer alloy will have more meat on its threads.

I hadn't heard that before but it does seem to make sense.

Andy, if you do order from Chronos maybe you could ask them about this and let us know what they say. I'd be interested.

Cheers

Julian

[jleyton]

Can I just say.... CAREFUL HOW DEEP YOU DRILL!!!!

Mark the drill with tape to the original hole depth.....

OH YES ! Probably the most important warning of all... and I forgot to mention it. Doh

Mind you, both the above posts won't matter if the hole is so worn that you can tap without drilling as I mentioned.

Cheers

Julian

[mike@thenook]

I pulled the inlet manifold off to get the waterpump out on saturday. I was expecting a mare getting the pump out but it came out ok thankfully, and the impeller has gone off to get machined. It was quite badly pitted so was worth doing, and Im fairly sure this is where it was leaking from

Ive turned my attention to the inlet manifold and can see 9 of the 12 threads for the bolts have been coiled already. The ones that havn't look right iffy though so I thought I may as well do them whilst in the area so to speak. I found this kit online
http://www.chronos.ltd.uk/acatalog/I...PAIR_KITS.html I need the 5/16 UNC one I believe?

However it seems quite cheap compared to others Ive seen. Ive never attempted a helicoil before. So the question is I suppose do I spend more money on a named kit , and if so recommendations? Or will this do the job?

Also any top tips to stop me screwing it up?

thks

Andy

Hi Andy,

I bought an excellent kit from RS Components http://uk.rs-online.com made by Recoil in Australia and the kit comes complete with the correct drill, tap and about 10 inserts.
Not sure about the kit you mention above though.
It's an easy job provided you do what Krt says and dont drill deeper than the original hole.
Good luck!

Cheers

[Bassy]

Thanks for the tips/advice everyone.

Much appreciated. Expect more questions when refitting the whole inlet manifold saga begins. Im sure there are worse designs, but none that immediately spring to mind.

[stag8manod]

Hi Bassy, The correct dill size for a 5/16 thread repair is 5/16. For a tapping lubricant use Kerosene or WD40 or one of the similar ones.
Cheers Ian A

[stag8manod]

Hi Mickey, I appreciate your point. In my 47 years in the engineering and motorsport I have always drilled the hole the same size as the thread I am replacing. 98% of these would have been done insitu freehand with an electric or air drill and never had a problem
Cheers Ian A

[Stagnant]

Hi Andy.

I used a Machine Mart (Clarkes) own 'helicoil' kit for the very same job with no problems, and they're not a top brand name either.
As others have said, go very slowly, tape your drill bit for depth, keep the tap lubed and turn it back a bit frequently.
And as my Dad (and all old wise ones) always said "measure twice, cut once"!

Good luck,

Mark

[Motorsport Micky]

Sorry Ian, I'd already removed my post I didn't want it to be too nitpicky.

Mickey

[Davenott]

Helicoils come in different depths. I found the ones in my kit were 1.5d, so I bought some 2d as these were the the size I was recommended for the inlet manifold.
Dave.

PS; I wonder if someone who knows there stuff might want to write 'how to use helicoils' and put it in the technical section, as I found the advice given when I asked the question very useful, and it seems to be a frequent question when dealing with the inlet manifold, hubs etc on the Stag.