28 replies to this topic

[iamweasel]

sweet
Twins it is. Now to find some! Seem to be quite a few on eBay - I'm just worried about getting stuck with a pair that need loads of work
Anyone know of any other places I could pick up a good 2nd hand pair?
oh - quick question: Now that you mention the rolling road - how much does that usually cost?

[minivanman]

For my 2p's worth I would say have a HIF38. As has been said they are much easier to set up and give pretty darn good performance. I had a HS4 with a standard filter until last week. I finally got my HIF on it and K&N filter, and all I can say is WOW! Everything is better - acceleration, exhaust note, top end, startup, its all completely different.

[fikus01]

rolling road round my way in essex is about £50 - £60 per hour and they take about 2 hours per car plus parts!! depends how easy it is to setup ur car!!

my first time at a rollin road was only £80 but the carb was spot on already!! they chucked in a new set of plugs, points, condensor, rotor arm, cap, leads as my stuff was all ancient and i figured they'd know wheat best to put on if it was needed!!

Edited by fikus01, 16 October 2006 - 11:00 PM.

[Austin]

Just a quick one.............
A hif44 is too big for your 998, no use whatsoever. the hif38 will work well with your engine, as will twin 1 1/4 SUs. both are likely to give similar performance, the twins may have a small advantage with better responsiveness due to higher air speed through the carbs. Set up properly, the twins should use no more fuel than the hif, maybe even less. Also, the myth of twin carbs 'going out of tune' all the time is completeley untrue. Once setup they will not need tuning any more often than a single.

[iamweasel]

Yeah, in the article on servicing twin 1 1/4s in MiniWorld November, they said the twins shouldn't go out of tune easily - unless something is worn.

I can't find an HIF 38 on eBay, so twin 1 1/4s seem to be the only realistic option to me at the moment. Plus I could follow that miniworld article and service them myself...

Thanks again for everyone's input

[Retro_10s]

i was preetty sure... minidave (?) sells HIF38's for about a tenner.

[fikus01]

apoligies for my lacking of brain power!! i've heard it mentioned several times that twins need re-tuning for summer / winter!! i did find this strange but accepted it as the norm for minis!! having done some reading i have some logic to the myth!!

if the carbs are mechanically identical then there is no problem with having them tuned once and that being it!!

on the other hand if they werent a matched pair and maybe the springs or damper pots werent working the same a lot of places will just thin the oil in 1 of the dampers to correct this rather than seek the cause of the problem (sticky or worn parts)!! im guessing that in that case with two different effective viscosities of oil in the damper they would perform differently with hot and cold weather!!

mite just be worthless rambling but it makes sense to me!!

[dude]

apoligies for my lacking of brain power!! i've heard it mentioned several times that twins need re-tuning for summer / winter!! i did find this strange but accepted it as the norm for minis!! having done some reading i have some logic to the myth!!

Sorry to but in, but this is kind of true.
Did anyone notice the drop in fuel prices last month?? This is due to the difference in the summer fuel to the winter fuel. The petrol suppliers had too much summer fuel left, so they flog it off cheap to the garages, thus cheap fuel for us. Different octane levels and all that rocket science stuff. I wont go into it, but i have worked in the oil industry before, and the fuel differs in a big way when it comes from the treatment plants from summer to winter. You think the smoke from tailpipes in winter is cause its cold, but its not much colder than some late summer mornings, its more smoky cause of the refinement procedure.
So different fuel octane levels mean different set ups for the carb....

But apart from that, i dont know much about carbs, just i got an old pair of weber 45s my 1275gt had back in the 80's that i want to clean up and put on my SPi (after the removal of the injection system) and people have been telling me that they wont work, theyre too powerful.....
They worked in 88.

They will work again....!!!

[Austin]

Yes, this may well be true (i have no idea so would not like to say), there is also the fact that colder running conditions, altitude differences, and many other factors decide the carburretion requirements. however there is no reason for any of these factors to affect twin carbs any more than a single. Interesting about summer/winter fuels though, ive never heard this before.

[iamweasel]

i was preetty sure... minidave (?) sells HIF38's for about a tenner.

only a tenner? any idea how I could get hold of him? I did a search and there are a few 'minidave' variations...

My car needs something for its asthma problem

[dude]

Twin carb, single carb all the same, need resetting in the winter and summer months.
Outside temp is not really a problem (your engine runs at more or less the same temp wether cold weather or hot, it just cools itself more efficiently at 100 mph in the winter...!! ) but the carb needs setting up due to the richness of fuel variations at different times of the year.
Just keep an eye out for the season changes and a drop in fuel price, then a sudden hike in the cost.


Sorry to be an anorak.....

[iamweasel]

Twin carb, single carb all the same, need resetting in the winter and summer months.
Outside temp is not really a problem (your engine runs at more or less the same temp wether cold weather or hot, it just cools itself more efficiently at 100 mph in the winter...!! ) but the carb needs setting up due to the richness of fuel variations at different times of the year.
Just keep an eye out for the season changes and a drop in fuel price, then a sudden hike in the cost.


Sorry to be an anorak.....

This whole "different fuels for different seasons" is quite interesting. Never had any idea about that sort of thing. I grew up in South Africa, where temperatures don't vary that much. and petrol prices only ever go up!

Got myself a pair of twin 1 1/4" SUs which I'm gonna service and get my machanic to set up for me. So hopefully soon I'll have no more carb woes

If anyone's looking for an HS4 for spares, let me know. the mechanic said it had a lot of wear (didn't say where though). I'll see when it's off...

[iamweasel]

so I got myself some twin 1 1/4s (AUD 69 L&R).
I'm in the process of cleaning and servicing them, but stupid stupid me dropped one and broke the plastic bit of the jet

So have to buy a new jet for the right-hand carb (£13.50). I figure if I'm buying a new jet, I might as well replace both (about £30 incl p&p from minispares), but... for £40 I can get a twin SU service kit from minisport. but - another £40 I've already spent money on heat shields, filters...
I bought a "service kit" off ebay for twin 1 1/4" SUs, but it didn't have jets. Actually I'm pretty sure it's not even for 1 1/4" SUs

carb woes continue...

[fikus01]

For my 2p's worth I would say have a HIF38. As has been said they are much easier to set up and give pretty darn good performance

hate to say he told you so, good luck all the same!! twins do sound nice when running well