6 replies to this topic

[whistler]

For those who are wondering what power you can expect from a 1098 engine with a little effort. 

I built an overbored 1098 from a template mentioned in an article by Keith Calver who, along with his friend Graham Russell in Oz, have had some remarkable results with small bore engines for those who can't access a 1275 lump.

Bored out for 0.100" Calver pistons, CST2005 head, Piper BP255 camshaft, HS6 carb and AC Dodd 1.3 rockers. Minispares ultralight flywheel with standard clutch.

Modified Maniflow LCB (to avoid hitting rubber cross CV joints) and Maniflow RC40 system.

45D distributor converted to electronic and curved by H&H Ignition.

Gearbox is a 4 synchro with magic wand conversion and A+ straight cuts. Final Drive is 3.4:1.

The objective was to have a mk1 with an engine that looked right for the period.

The only modern upgrades I made were disc brakes, a right hand tank and rosepetal wheels.

Went for a final rolling road check and power run today.

 

Posted previously on FB and Mk1 Forum.

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[bpirie1000]

Good effort well done.. also looks lovely...

[KTS]

that's pretty impressive !

 

interesting that your drag loss was 8bhp less than mine (with helical gears) measured on the lynxae maha.  I'm wondering how much, if any, of that could be straight cut vs helical gears....

[Bjarnetv]

Very nice! 

I'm building a very similar engine, so its going to be interesting seeing where I end up compared to this. (probably a bit lower since I'm using Hepolite STD size mg1100 pistons instead of oversized flat-tops)

what needle did you use for the HS6?
I know the profile will have to be modified in the end, but there isnt much info out there on HS6 carbed minis, so im not really sure what to needles to start with before sending it off for tuning.
 

And how does it drive with the lightened flywheel?
I was thinking of keeping the standard flywheel in mine to keep it easy to drive, but a lightened one is of course mighty tempting.

[whistler]

that's pretty impressive !

 

interesting that your drag loss was 8bhp less than mine (with helical gears) measured on the lynxae maha.  I'm wondering how much, if any, of that could be straight cut vs helical gears....

Not a question I'm qualified to answer but I would guess so.

[whistler]

Very nice! 

I'm building a very similar engine, so its going to be interesting seeing where I end up compared to this. (probably a bit lower since I'm using Hepolite STD size mg1100 pistons instead of oversized flat-tops)

what needle did you use for the HS6?
I know the profile will have to be modified in the end, but there isnt much info out there on HS6 carbed minis, so im not really sure what to needles to start with before sending it off for tuning.
 

And how does it drive with the lightened flywheel?
I was thinking of keeping the standard flywheel in mine to keep it easy to drive, but a lightened one is of course mighty tempting.

The lightened flywheel (Minispares Ultralight) takes some getting used to for starting off. Makes it difficult to drive onto car ramps (high first gear as well) but apparently it does aid acceleration.

The needle for my setup in the HS6 was a BDL which is the standard needle for an MG Metro in a HIF44. The HS6 having the same output diameter but only 40mm inlet diameter. Have to a different air filter plate as well. Currently using a Pipercross HS6 foam air filter from Minispares. I had a cone filter on but the noise was too much for my delicate ears. I was fortunate that the BDL needle fuelled the engine perfectly without needing thinning.

[Java_Green]

For those who are wondering what power you can expect from a 1098 engine with a little effort.
I built an overbored 1098 from a template mentioned in an article by Keith Calver who, along with his friend Graham Russell in Oz, have had some remarkable results with small bore engines for those who can't access a 1275 lump.
Bored out for 0.100" Calver pistons, CST2005 head, Piper BP255 camshaft, HS6 carb and AC Dodd 1.3 rockers. Minispares ultralight flywheel with standard clutch.
Modified Maniflow LCB (to avoid hitting rubber cross CV joints) and Maniflow RC40 system.
45D distributor converted to electronic and curved by H&H Ignition.
Gearbox is a 4 synchro with magic wand conversion and A+ straight cuts. Final Drive is 3.4:1.
The objective was to have a mk1 with an engine that looked right for the period.
The only modern upgrades I made were disc brakes, a right hand tank and rosepetal wheels.
Went for a final rolling road check and power run today.

Posted previously on FB and Mk1 Forum.

I am new to these different variables. The obvious one, I can figure, but could somebody clarify?