29 replies to this topic

[monster_mini]

hi

my dad used to race his austin healy sprite with twin inch and a 1/4s carbs on(and now they are just in a box at the back of the garage so i want them:P)

soo far i know i obviously have to change the inlet manifold, but im sure i have read somewhere there are other parts that need to be changed?

if anyone could give me some guidence and reasons why then that would be great

thanks

nick

[Dan]

The float bowl angle adaptors need to be changed for them to fit the car, all other parts will depend on your tuning.

[samsfern]

The float bowl angle adaptors need to be changed for them to fit the car, all other parts will depend on your tuning.

haha, beat me to it.

[monster_mini]

by depending on your tuning, does that mean the needle ect?

also where would you recomend buying them? and im pretty sure i will need a new inlet manifold too:( any advice on which one too get? im in the process of building a 1293 with stage 3 head, maybe 731 cam, lightened flywheel and then just exhaust if that makes a difference:)

thanks

[dklawson]

Before getting excited about using the AH carbs on the Mini, take a look at them and discuss them with your dad.

I thought the Bugeye (Frogeye) used H2 carbs, not HS2 like most Minis. The older H2 carbs are still decent but they are a bit different to work with and can have problems with their seals leaking. I'm not trying to discourage you, I would just research this a bit further before pursuing the conversion.

[monster_mini]

ok, thanks for the heads up,

well im taking them into the guy that tunes my engine and rebuilds carbs(called d and b carburetta specialists:P) tomorow, soo hopefully he will be able to shed some light on what to do:)

thanks

nick

[monster_mini]

i took them in thismorning, and he said they were cooper hs2's and i should just bolt them straight on:P:)

if i bolt them on to my 998, do you think it will be possible to play with the mixture just by hand to get it atleast running and driveable till i can take it in to be tuned?

any advice? should i strip them and clean them/replace seals and gaskets anyway as they havent been used in 20 years?

thanks

[dklawson]

If they were from an AH Sprite, they will not just bolt on to a Mini manifold. As mentioned above, the float bowls will be at the wrong angle. There are rubber/plastic keyed washers between the float bowl and carb body that must be changed to get the float bowl level. Likewise, the AH Sprite manifold should fit the Mini cylinder head without issue... but it will also be at the wrong angle.

There are some basic things you should do to prepare the carbs for use since they have been in storage for a long time. Assume the float bowls may have gummed fuel in them and plan on cleaning them, the jet tube, and the needle to remove fuel varnish and gum. There are basic settings described in the Haynes and SU manuals that will help you get the engine started. With duals you will need to balance the airflow in addition to the mixture and choke adjustments. It's a bit much to go into here until you've had a chance to read over the steps in a manual.

[monster_mini]

ok thanks for all the help dklawson, i've dug out one of my miniworld mags and it tried to show how to find out which ones they were, but the tag on it has gone, all i have is aug and then i can only make out a hand printed 55 after it, which doesnt come up in any of the spec in the magazine:/ if i could find a carburetter specialist near me, would it be best to take them and the two manifolds i have to them and ask them for advice? would putting any photo's on here help you or anyone else be able to help me out?

thanks

[dklawson]

Pictures do help. Since you brought it up, take a look at the links below and see which looks like your carbs.

Older H2 Carbs from early Spridgets and possibly very early Minis.
http://www.min-e-bit.../mon 21 005.jpg
Note that on the H-series carbs the float bowl is rigidly bolted to the carb and there are large brass levers that lift and lower the jets.


Later HS2 Carbs. Common on many A-series and Triumph engines.
http://www.paltech1....res/3-13004.jpg
Note that on HS-series carbs the float bowls are attached to the jet with an external, spring covered, flexible tube. There are very compact linkages to lift and lower the jets.

[monster_mini]

they're definatly the hs2 carbs:)

i have two inlet manifolds for them and they both give difference angles? how can i check what the manifolds are from?

thanks

[dklawson]

Look carefully over the manifold castings. You are likely to find numbers cast into the manifold. Post those here and someone will be able to identify them for you.

There were a lot of different A-series engines used in rear and front wheel drive cars. Their manifolds were typically a bit different. You may have a Mini manifold, a Spridget manifold, or an ADO16 manifold, all of which are fairly common with dual carbs... perhaps a little less so with the ADO16.

[monster_mini]

ok thanks

manifold one has- 12g299vaf on it

manifold two has- 12a661 on it

they both also have mowog casted into them aswell further round.

hope someone can help:)

thanks for all the help so far:)
nick

[Stevee]

Mowog is Morris Engines and parts :]

[dklawson]

A quick search indicates that the 12G299 manifold is an Austin America part (ADO16).

The second manifold is a 998 Mini twin carb manifold.

See these two related threads:
http://www.theminifo...howtopic=108966

and

http://www.minimania...3/msgthread.cfm
(A table at this link should help you locate suitable casting numbers).