32 replies to this topic

[timmy850]

Would this 1098 be different to the South African big bore 1098 that used the same cylinder block as our 1275 but different pistons and crank?

 

I think all our big bore 1098 engines had the same 12G940 head as the 1275E but with 11 studs and also used the 1275 GTS block to match the 11 studs. Though, the extra 2 studs don't really add anything other that the extra effort to torque the extra studs to a lower setting than the rest.

The regular 1098 was used in the Morris/Austin 1100 and some mini models. It's essentially the same as a 998 but a longer stroke and different pistons. It's long stroke and small bore

 

Very different to the SA 1100, which was big bore and short stroke. 

[CdnAustinAmerica]

Mine made 78bhp.

 

Zounds! What did you do to yours then? A similar build?

 

I also am putting a 1 7/8 stainless header with o2 bung past collector, and single box RC40 to replace the pea shooter factory style manifold, Metro intake. I'm hoping the HS4 single is still enough, I'll be tuning it using the help of a wideband sensor and probably modifying a needle so Dodd would hopefully approve.

 

Thanks for all the help and advice guys.

 

 

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

[whistler]

 

Mine made 78bhp.

 

Zounds! What did you do to yours then? A similar build?

 

I also am putting a 1 7/8 stainless header with o2 bung past collector, and single box RC40 to replace the pea shooter factory style manifold, Metro intake. I'm hoping the HS4 single is still enough, I'll be tuning it using the help of a wideband sensor and probably modifying a needle so Dodd would hopefully approve.

 

Thanks for all the help and advice guys.

 

 

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

 

Followed Keith Calver template. Flat top KC +0.100" pistons, decked to within 5 thou, same CR as you. Piper BP255 cam, KC lifters (cam followers), KC modified 202 head with 28cc chamber and flowed ports. HS6 carb. Balanced crank etc and ultralight MS flywheel. Max power 78bhp at 5620 rpm, max torque 80ftlbs at 4470 rpm.

[CdnAustinAmerica]

 

 

Mine made 78bhp.

 

Zounds! What did you do to yours then? A similar build?

 

I also am putting a 1 7/8 stainless header with o2 bung past collector, and single box RC40 to replace the pea shooter factory style manifold, Metro intake. I'm hoping the HS4 single is still enough, I'll be tuning it using the help of a wideband sensor and probably modifying a needle so Dodd would hopefully approve.

 

Thanks for all the help and advice guys.

 

 

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

 

Followed Keith Calver template. Flat top KC +0.100" pistons, decked to within 5 thou, same CR as you. Piper BP255 cam, KC lifters (cam followers), KC modified 202 head with 28cc chamber and flowed ports. HS6 carb. Balanced crank etc and ultralight MS flywheel. Max power 78bhp at 5620 rpm, max torque 80ftlbs at 4470 rpm.

 

 

 Okay thanks, yeah similar except for your overbore is more, interesting. How did you find the lightened flywheel to behave like?

[whistler]

 

 

 

Mine made 78bhp.

 

Zounds! What did you do to yours then? A similar build?

 

I also am putting a 1 7/8 stainless header with o2 bung past collector, and single box RC40 to replace the pea shooter factory style manifold, Metro intake. I'm hoping the HS4 single is still enough, I'll be tuning it using the help of a wideband sensor and probably modifying a needle so Dodd would hopefully approve.

 

Thanks for all the help and advice guys.

 

 

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

 

Followed Keith Calver template. Flat top KC +0.100" pistons, decked to within 5 thou, same CR as you. Piper BP255 cam, KC lifters (cam followers), KC modified 202 head with 28cc chamber and flowed ports. HS6 carb. Balanced crank etc and ultralight MS flywheel. Max power 78bhp at 5620 rpm, max torque 80ftlbs at 4470 rpm.

 

 

 Okay thanks, yeah similar except for your overbore is more, interesting. How did you find the lightened flywheel to behave like?

 

Need more revs than standard to pull off. More difficult to drive up onto ramps but  you get used to it. Engine revs more easily.

[CdnAustinAmerica]

 

 

 

 

Mine made 78bhp.

 

Zounds! What did you do to yours then? A similar build?

 

I also am putting a 1 7/8 stainless header with o2 bung past collector, and single box RC40 to replace the pea shooter factory style manifold, Metro intake. I'm hoping the HS4 single is still enough, I'll be tuning it using the help of a wideband sensor and probably modifying a needle so Dodd would hopefully approve.

 

Thanks for all the help and advice guys.

 

 

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

 

Followed Keith Calver template. Flat top KC +0.100" pistons, decked to within 5 thou, same CR as you. Piper BP255 cam, KC lifters (cam followers), KC modified 202 head with 28cc chamber and flowed ports. HS6 carb. Balanced crank etc and ultralight MS flywheel. Max power 78bhp at 5620 rpm, max torque 80ftlbs at 4470 rpm.

 

 

 Okay thanks, yeah similar except for your overbore is more, interesting. How did you find the lightened flywheel to behave like?

 

Need more revs than standard to pull off. More difficult to drive up onto ramps but  you get used to it. Engine revs more easily.

 

 

Thanks! I decided to keep my flywheel as is after deliberation and asking a few others, where I live there can be frequent stop and go traffic and it will be a daily driver so I'm keeping the low rev ease of use, might also keep my idle smoother with the cam.

Its going in soon and I'll have some fun profiling a needle, carb has an AAA in it which was a bit rich before so hopefully a good starting point but I'll borrow a few to play with.

 

 If anyone could weigh in on a needle(s) to start with that would be great, maybe something that worked in a similar setup (single HS4 in recently rebuilt condition), or at least a friendly way to mount it in a drill chuck, don't have access to a lathe.

[timmy850]

Mine is:
1098 +080 flat top pistons
Heavily modified 12G202 head (bigger valves, porting, chamber mods)
Running about 10.5:1 compression
RE266SS cam
Lightened stock flywheel
3.44 diff
Maniflow freeflow exhaust manifold

I have a HIF44 on a metro manifold, BCE needle, yellow spring and 20/60 oil. I’d think a single HS4 wouldn’t be enough for my engine

[gazza82]

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

12A185 is off the first Mk1 Cooper S according to Mr Calver's site.

[CdnAustinAmerica]

Mine is:
1098 +080 flat top pistons
Heavily modified 12G202 head (bigger valves, porting, chamber mods)
Running about 10.5:1 compression
RE266SS cam
Lightened stock flywheel
3.44 diff
Maniflow freeflow exhaust manifold

I have a HIF44 on a metro manifold, BCE needle, yellow spring and 20/60 oil. I’d think a single HS4 wouldn’t be enough for my engine

 

HIF44 and 38s are rare here, nearly all British imports stopped in 1980. I'll try and get one later. Also not a lot of HS6's either, most places that would have had lots of carb bodies have closed/sold/scrapped their inventory.

There was a british garage here that changed owners and they scrapped something like 150 carburettors.

Edited by CdnAustinAmerica, 09 November 2024 - 07:28 PM.

[timmy850]

If anyone is curious that 12A185 head looked very similar to a 202 once I got it apart, so if you can find one it might be a good option.

12A185 is off the first Mk1 Cooper S according to Mr Calver's site.

For some strange reason, they had a 12A185 on the small bore engine that was nearly identical to a 12G202. Then there was a 12A185 big bore head on the very early Cooper S.

[timmy850]

Mine is:
1098 +080 flat top pistons
Heavily modified 12G202 head (bigger valves, porting, chamber mods)
Running about 10.5:1 compression
RE266SS cam
Lightened stock flywheel
3.44 diff
Maniflow freeflow exhaust manifold

I have a HIF44 on a metro manifold, BCE needle, yellow spring and 20/60 oil. I’d think a single HS4 wouldn’t be enough for my engine

HIF44 and 38s are rare here, nearly all British imports stopped in 1980. I'll try and get one later. Also not a lot of HS6's either, most places that would have had lots of carb bodies have closed/sold/scrapped their inventory.
There was a british garage here that changed owners and they scrapped something like 150 carburettors.

I imported the HIF44 as there aren’t many here either (Australia) and especially hard to find with the mini specific brackets etc

The 1.5” carb should work decently, but may be a restriction at the top end

[whistler]

 

Mine is:
1098 +080 flat top pistons
Heavily modified 12G202 head (bigger valves, porting, chamber mods)
Running about 10.5:1 compression
RE266SS cam
Lightened stock flywheel
3.44 diff
Maniflow freeflow exhaust manifold

I have a HIF44 on a metro manifold, BCE needle, yellow spring and 20/60 oil. I’d think a single HS4 wouldn’t be enough for my engine

 

HIF44 and 38s are rare here, nearly all British imports stopped in 1980. I'll try and get one later. Also not a lot of HS6's either, most places that would have had lots of carb bodies have closed/sold/scrapped their inventory.

There was a british garage here that changed owners and they scrapped something like 150 carburettors.

 

I use a HS6 on my 1098. These were used on a variety of larger engined cars, often as twins. The main difference between the HS6 and HIF44 is the air filter end is 40mm and the HIF44 is 44mm. The other end is 44mm on both.

[CdnAustinAmerica]

 

 

Mine is:
1098 +080 flat top pistons
Heavily modified 12G202 head (bigger valves, porting, chamber mods)
Running about 10.5:1 compression
RE266SS cam
Lightened stock flywheel
3.44 diff
Maniflow freeflow exhaust manifold

I have a HIF44 on a metro manifold, BCE needle, yellow spring and 20/60 oil. I’d think a single HS4 wouldn’t be enough for my engine

 

HIF44 and 38s are rare here, nearly all British imports stopped in 1980. I'll try and get one later. Also not a lot of HS6's either, most places that would have had lots of carb bodies have closed/sold/scrapped their inventory.

There was a british garage here that changed owners and they scrapped something like 150 carburettors.

 

I use a HS6 on my 1098. These were used on a variety of larger engined cars, often as twins. The main difference between the HS6 and HIF44 is the air filter end is 40mm and the HIF44 is 44mm. The other end is 44mm on both.

 

 

I've gotten my hands on an HS6 from a 60s Volvo based on its tag, converted the float to be at the proper angle.

Did you modify your needle at all?

Also curious what you used to mount it, I got an hif44 plate/heat shield although I'm not sure of the best way to do the reurn springs. I will probably swap the linkage from the HS4 on mine, it has the Canadian linkage which pulls directly down on the throttle instead of over the top pull up, has a very short accelerator cable. I don't have the  linkage for anything else.

Edited by CdnAustinAmerica, 16 November 2024 - 08:16 AM.

[whistler]

 

 

 

Mine is:
1098 +080 flat top pistons
Heavily modified 12G202 head (bigger valves, porting, chamber mods)
Running about 10.5:1 compression
RE266SS cam
Lightened stock flywheel
3.44 diff
Maniflow freeflow exhaust manifold

I have a HIF44 on a metro manifold, BCE needle, yellow spring and 20/60 oil. I’d think a single HS4 wouldn’t be enough for my engine

 

HIF44 and 38s are rare here, nearly all British imports stopped in 1980. I'll try and get one later. Also not a lot of HS6's either, most places that would have had lots of carb bodies have closed/sold/scrapped their inventory.

There was a british garage here that changed owners and they scrapped something like 150 carburettors.

 

I use a HS6 on my 1098. These were used on a variety of larger engined cars, often as twins. The main difference between the HS6 and HIF44 is the air filter end is 40mm and the HIF44 is 44mm. The other end is 44mm on both.

 

 

I've gotten my hands on an HS6 from a 60s Volvo based on its tag, converted the float to be at the proper angle.

Did you modify your needle at all?

Also curious what you used to mount it, I got an hif44 plate/heat shield although I'm not sure of the best way to do the reurn springs. I will probably swap the linkage from the HS4 on mine, it has the Canadian linkage which pulls directly down on the throttle instead of over the top pull up, has a very short accelerator cable. I don't have the  linkage for anything else.

 

I had my needle sorted out on a rolling road here in South Wales. The needle that they fitted was a BDL which didn't need modifying. I used an MG Metro inlet manifold and abutment plate and made a small bracket to fit to the bottom of the plate for a return spring. I fitted a Piper Foam air filter for a HS6.

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Edited by whistler, 16 November 2024 - 03:12 PM.

[CdnAustinAmerica]

Which spring did you use?

Edited by CdnAustinAmerica, 25 November 2024 - 08:44 AM.