ChrisW
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| posted on 5/9/11 at 09:37 PM |
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Reducing hole size in steel casting
Trying to assemble an MG ZS with a T16 turbo lump. The engine mount on the T16 is on the end of the block where you would normally expect the water
pump to live. In fact, it looks like it was originally designed for the water pump as there is it's bolted on with six bolts in a circle with a
large waterway behind.
Anyway, I have to swap the 820 mount for one from a 420 non-turbo. Same t-series engine but without a turbo. Went to do it tonight and it seems the
n/a car used M8 bolts instead of the M6 on my turbo engine. Consequently the holes in the casting are 2mm too large diameter.
Obviously I can't use larger bolts without drilling out the block and re-tapping which doesn't sound feasible to me.
Anyone shed some light on how I solve this? Can I buy a bolt with 10mm or so of M8 shank then an M6 thread? Or maybe buy inserts to go into the
casting?
Thanks, Chris
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Miks15
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| posted on 5/9/11 at 09:46 PM |
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Maybe get some short collars made with 8mm OD and 6mm ID?
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big-vee-twin
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| posted on 5/9/11 at 10:15 PM |
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Think your looking for a shoulder bolt like this one8mm (M6) X 25 Allen Cap Shoulder Screw Bolts 4 PACK | eBay
Has 8mm body 6mm thread
or this one
M6 X 8 X 10 SHOULDER BOLTS CAP ALLEN 12.9 BLACK X 4 | eBay
[Edited on 5/9/11 by big-vee-twin]
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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ChrisW
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| posted on 5/9/11 at 10:39 PM |
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Inserts are the way I thought of, but I don't have a lathe so cutting them to the right length accurately would be difficult.
Those shoulder bolts look promising thought if I can find the right size. I measured properly just now and they're actually m10 to m8. 5 of
them need to be 25mm with 10mm collars and the sixth needs to be 55mm long with 40mm collar. However I guess the collars should be slightly less than
the size of the casting (or I use a washer) to make sure the bolt is acting on the casting not the collard going solid on the block?
Chris
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MikeRJ
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| posted on 5/9/11 at 11:17 PM |
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Why is drilling and tapping the block to M8 not feasible?
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spiderman
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| posted on 5/9/11 at 11:58 PM |
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Eiither drill block and tap with an M8 tap or put an M8 bolt into the casting a little short of being flush and fill the remaining void with weld cut
the bolt off flush and drill and tap to M6. Just a couple of suggestions.
I would personnaly go for drilling and tapping the block as I did when I snapped a bolt off in the block when fitting my water pump. It is easier
than you think
Spider
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mark chandler
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| posted on 6/9/11 at 07:23 AM |
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Sleeve the 6mm bolt with a bit of tube, plenty of small steel and ali choices in B&Q and Wickes etc for a couple of ££.
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liam.mccaffrey
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| posted on 6/9/11 at 07:23 AM |
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I did a similar thing about 3 weeks ago and had some 14mm to 1/2" reducing collars made for my suspension uprights only cost a couple of quid
each.
I can get them machined for you for very little and sent on.
That is the best way to do it imho
[Edited on 6/9/11 by liam.mccaffrey]
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ChrisW
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| posted on 6/9/11 at 05:57 PM |
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Yeah I think the sleeve way is the best. Much as I'd like to tap the holes out I'm worried about ending up with a scrap block as
it's not something I've done before.
I've had a good look around and can't find those shoulder bolts in the right size unfortunately.
Liam - will u2u you about getting some sleeves made if you're willing to help. Else, if anyone has a lathe and fancies knocking something up
for me please shout! 
Chris
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