3 replies to this topic

[cheesebadger]

Engine build options... (something a bit different)

 

My current engine is a standard 1098 with 12G295 head with twin HS2s, with unknown cam (could be standard). This engine was in the car when I bought it 4 years ago. It has served me well, but now its time for a fresh engine...

 

I would like to do something different, so thinking small bore rather than standard 1275 block. Also much easier to find for a reasonable price!

I currently use the car for weekend fun, but could be interested in track days in the future. The car is a mk1, so i'm not sure it would be suitable for all out competition work (although it is not original enough to worry about keeping it 100% standard)

 

Option 1)

I have got hold of a pair of Hillman Imp pistons from a friend. I could build these into a 1215cc lump as detailed in Vizard. This would be a period relevant mod, that would create a nice torquey engine for A-road driving.

 

Option 2)

I have also found a SC12 supercharger as used on a number of kits in Aus. I was thinking of doing a custom 1098 +40 blow through supercharger setup. This would create plenty of torque, and would be great fun, and a challenge to build!!!

 

Option 3)

Combine both options, but I would be worried about the strength of the block for forced induction give the larger overbore required for the imp pistons. I'm less keen on this option due to potential reliability issues...

 

Anyone built either of these engines in the past? Or anything similar? Any advice?

Any other opinions appreciated...

 

Cheers,
Rich

[Gr4h4m]

I have a small bore +sc12 and it's a great combination.

[cheesebadger]

I have a small bore +sc12 and it's a great combination.

 

I have read through your build topics a few times. Part of my inspiration when I got offered the SC12 in the first place...

From memory, are you running suck through?

 

Are you utilising the factiry clutch on the S/C? What rpm have you got it kicking in at?

 

I am starting to lean towards a small bore S/C but not using the imp pistons as I think the walls would be too weak. Can you recommend a good source of small bore pistons that are suitable for forced induction? Forged or Cast?

 

Cheeers, Rich

[Gr4h4m]

Well in answer to your questions:

I run suck through, with megajolt, and a simple water injection kit. The sc clutch is factory and switches on with the ignition and stays on.

The best pistons I could find where the graham Russell available from Keith calver. Getting your cr to a reasonable point is a little harder as mine were flat tops, but check with Keith as depending on the size they might do a dish?
I did run the kit since 2007 on factory pistons from 1969 at 7-10psi, no issues. Fueling and ignition play a big part in keeping everything together.

Just upgrading everything to run the sc injection kit...