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Drilling end of crank
lsdweb - 28/9/15 at 04:51 PM

Hi All

I'm trying to get my Striker together over the next couple of months, and one of the problems I have is that the K series engine was built for a FWD application and the end of the crank doesn't have a hole large enough to take the spigot bearing / gearbox input shaft. It's a 1100 crank.

Taking the crank out to get it bored seems to be the only option but as the engine has been fully rebuilt, I really don't want to have to strip it all!

Any thoughts??

Ta

Wyn

Theshed - 28/9/15 at 05:08 PM

I think you will need to grit your teeth and get stripping. The hole needs to be perfectly concentric (or as near as dammit) otherwise you will destroy expensive bits... The only way to do that is to bore the hole. Even using a succession of drills you are not going to do an accurate job.

I guess you could get the engine running - fabricate a boring jig and bore out the hole using the engine as a lathe but it would be far easier just to whip the crank out.

liam.mccaffrey - 28/9/15 at 05:15 PM

I could build a jig to do that (to my own engine!!!!!) I wouldn't personally contemplate doing it on your engine due the consequences/cost of screwing it up.

It can be done though, whether its cost effective though is another thing. Your engine isn't run in yet is it

EDIT
You could machine a series of drill guides, to centre the hole and finish off with correct nominal size reamer.

[Edited on 28/9/15 by liam.mccaffrey]

Ugg10 - 28/9/15 at 05:32 PM

If you are careful it can be done with a mag drill mounted on the flywheel. This is how my puma 1.7 was done as far as I know.

femster87 - 28/9/15 at 05:44 PM

Wyn, how much smaller is the recess?

Is it possible to machine down the input shaft tip on the gearbox and use custom made phosphorus bronze spigot bearing?

lsdweb - 28/9/15 at 05:47 PM

Thanks guys

Femi - I think it's only about 12mm - too small I think by the time I fit a bearing etc. Did you find a clutch / flywheel in the end?

Ta

Wyn

lsdweb - 28/9/15 at 05:49 PM

quote:
Originally posted by liam.mccaffrey
I could build a jig to do that (to my own engine!!!!!) I wouldn't personally contemplate doing it on your engine due the consequences/cost of screwing it up.

It can be done though, whether its cost effective though is another thing. Your engine isn't run in yet is it

EDIT
You could machine a series of drill guides, to centre the hole and finish off with correct nominal size reamer.

[Edited on 28/9/15 by liam.mccaffrey]


Cheers Liam

The engine has never been run! What you're saying makes sort of sense to a technical numpty to me!

W

cliftyhanger - 28/9/15 at 06:07 PM

Can you not bore the flywheel and put a bearing in there? I know some cars used the bush in the flywheel method.

Griff51 - 28/9/15 at 06:36 PM

Only issue I can see is crankshafts are harder than a hard thing! Normal drills need not apply.
Maybe some sort of adapter between crank and flywheel?

Paul Turner - 28/9/15 at 07:29 PM

I seem to remember Caterham had this same issue when they fitted 1.4's back in the early 90's. Probably wrong but I have a vague recollection they fitted a bronze bush instead of the normal bearing.

femster87 - 28/9/15 at 07:52 PM

quote:
Originally posted by lsdweb
Thanks guys

Femi - I think it's only about 12mm - too small I think by the time I fit a bearing etc. Did you find a clutch / flywheel in the end?

Ta

Wyn


Yes got a wrong one from burton power. Still trying to find the right one

40inches - 28/9/15 at 07:57 PM

The spigot bearing on the Jag/Duratec engine is in the Flywheel. Is this a possibility for you?

rdodger - 28/9/15 at 08:19 PM

quote:
Originally posted by 40inches
The spigot bearing on the Jag/Duratec engine is in the Flywheel. Is this a possibility for you?


Same for the MX5

lsdweb - 28/9/15 at 08:28 PM

quote:
[i

Yes got a wrong one from burton power. Still trying to find the right one
Let me know if you're struggling as I've got a couple of clutches.

lsdweb - 29/9/15 at 07:53 AM

The more I think about it, the more an adaptor of some kind to fit a bearing to the flywheel may be an option. I have a Type 9 gearbox with a 'short' input shaft which is too short. I was lying in bed thinking that maybe I could kill two birds with one stone so to speak.

Off to take some measurements!

Wyn

Hornet - 29/9/15 at 09:09 AM

Hi m8 I Ihabe drilled 3 engines with mag drill. Absolutely no problems and took about 10 mins to do. Would have no hesitation in doing it again. Really really easy to do.

SPYDER - 29/9/15 at 10:11 AM

Maybe get an adaptor like this machined up?


Hornet - 29/9/15 at 10:50 AM

Most people try to reduce the weight of flywheels to assist with getting higher revs quicker. Fitting an adapter will increase the weight.

Angel Acevedo - 29/9/15 at 02:04 PM

quote:
Originally posted by Hornet
Most people try to reduce the weight of flywheels to assist with getting higher revs quicker. Fitting an adapter will increase the weight.


You are right, but, being so close to the axis I donīt think it will affect acceleration a noticeable amount.
But... Then again... Every little weight saved counts...
I canīt say much as Iīm building a locost TANK!! due to the fact that I read too much american literature therefore my original bias towards Muscle over lightweight.
I have changeed my mind, but too late/expensive to change direction...

Paul Turner - 29/9/15 at 02:23 PM

QED still list a spigot bush to suit the K series to Ford gearbox

http://qedmotorsport.co.uk/qed-shop/rover-k-series/crankshafts/spigot-bearing-bush-to-take-ford-gearbox

Would this help.

Like I said earlier, sure Caterham used something like this.

lsdweb - 29/9/15 at 03:18 PM

quote:
Originally posted by Paul Turner
QED still list a spigot bush to suit the K series to Ford gearbox

http://qedmotorsport.co.uk/qed-shop/rover-k-series/crankshafts/spigot-bearing-bush-to-take-ford-gearbox

Would this help.

Like I said earlier, sure Caterham used something like this.


Thanks Paul

Unfortunately that particular bush is to fill the gap between the std K-Series crank and a Ford-type spigot bearing (QED's words).

The adaptor is still an option (I have an ultra light flywheel so adding a bit won't make a huge difference but I appreciate it's not the best option). The adaptor won't help with the 'too short' input shaft though so it's become less attractive.

quote:
Originally posted by Hornet
Hi m8 I Ihabe drilled 3 engines with mag drill. Absolutely no problems and took about 10 mins to do. Would have no hesitation in doing it again. Really really easy to do.


Drilling the end of the crank frightens the sh*t out of me! I'm not very handy with stuff like that (can't knock a nail in straight) and the engine cost too much to mess up! I have a spare engine (thanks Liam) which I could 'practice' on but I'd still be panicking!

Regards

Wyn

Paul Turner - 29/9/15 at 03:31 PM

quote:
Originally posted by lsdweb
Unfortunately that particular bush is to fill the gap between the std K-Series crank and a Ford-type spigot bearing (QED's words).


That makes sense looking at it again.

I still have a memory that Caterham used a bronze bush but that may have replaced both the spigot gearing and sleeve with one part. Its a long time ago.