7 replies to this topic

[johnR]

I've just bought some twin MGB HS4s to re-furbish - I don't really want to shell out for two more filters if I can re-purpose my HS2 ones. Would I be right in saying that it's only the baseplates that differ? has anyone made new ones to convert them?

 

[sonscar]

I fitted Kand N to my MGB and it ran terrible.It needed stub stacks in the filter backplate to cure it.I suspect making the holes bigger will run into problems with the existing holes but it is not insurmountable,Steve..

[johnR]

I fitted Kand N to my MGB and it ran terrible.It needed stub stacks in the filter backplate to cure it.I suspect making the holes bigger will run into problems with the existing holes but it is not insurmountable,Steve..

Interesting to hear that - I think that stub stacks won't fit in the Mini cones - my HS2's run fine without them though. i was thinking of having a tool machined to stamp the basic plate shape then cut holes as required - there must be demand for 'conversion plates' for people upgrading from HS2 to HS4 

[GraemeC]

Think I'd just use a HS4 gasket to mark the baseplate and then adjust it to suit.

 

There is a very shallow trumpet that K&N themselves make - think MiniSpares sell them.  I can't see them making that much difference between running terrible and running OK though.

Edited by GraemeC, 19 August 2021 - 01:01 PM.

[sonscar]

Unlike the mini the MGB has ali backplates which are already nicely radiused and they were obviously there for a reason.For what the K&N cost the construction was flimsy and the supplied cork gasket a joke which had no chance of sealing due to the thin backplates.This was 15 years ago and I have never bought any more.Your mileage may vary,Steve..

[timmy850]

I was planning on using some HS2 filter bases on my H4 carbs, it did look like they’d fit with a bit of dremel grinding and slotting the holes a bit. I haven’t tried it yet, but they did look reasonably close

These slim stub stacks should fit:
https://www.ebay.com...0-/173528483220

http://www.minispare...assic/SS51.aspx

Edited by timmy850, 19 August 2021 - 08:36 PM.

[johnR]

I was planning on using some HS2 filter bases on my H4 carbs, it did look like they’d fit with a bit of dremel grinding and slotting the holes a bit. I haven’t tried it yet, but they did look reasonably close

These slim stub stacks should fit:
https://www.ebay.com...0-/173528483220

http://www.minispare...assic/SS51.aspx

According to Vizard the cross section radius of the stacks should be much greater (which is where you then run into clearance problems on one side) I may make my own custom ones by casting them in resin.

[Turbo Phil]

There’s plenty of stub stacks that will fit inside a cone. I did some testing on the flowbench of several different ones, have a read of this.

https://www.theminif...220-stub-stack/

Phil.