Hopefully some final comments from me on this since I only jumped in to correct some misconceptions and answer some questions that were being asked:

1) Its easy to say that a carb gets better fuel mileage or flows more than another, its harder to combine throttle response, fuel mileage, and higher flow to support higher HP in the same carb - and that's what I'm after, a carb that's a good compromise, that will meet a wide range of needs. I welcome others to point out other carb/manifold combinations that will do the same thing, publish results and tuning details, tell us what the costs are or market the parts as easy to install kits for the benefit of all owners of older Volvos.

2) Its comparatively easy to tune a carb for fuel economy at the expense of throttle repsonse and/or power. Its easy to claim a carb is better without even trying the one you are comparing it to.

3) We know that SUs wear out and that the normal rebuilds, depending on who does them, don't completely rebuild the carb, you don't get back a carb that is " good as new" as there are areas of wear that are not replaced. And actual, new SU carbs are very expensive. The HS6 is limited in is flow potential, which is the reason that some who have criticized some of my statements in this thread, have recommended to others, in other threads, that they switch to the HIF carb because of its higher flow potential.

4) I've got nothing against SU carbs. But I get calls and emails every week from people who don't like their SU's, can't seem to get them tuned right, etc. They want to replace them and want to know whether to go for a downdraft weber or a sidedraft weber. Up to now, I have usually recommended to most sticking with the SUs and getting them rebuilt, from now on I will mention the Mikunis as another option, especially where the person has or intends to modify the engine for higher performance.

5) Both Weber and Mikuni recently released carbs specifically as SU replacements.
Obviously they were designed to be improvements over the 50 year old carbs they were designed to replace. I've tried them both, and have done comparisons with the HS6 and the HIF6 on the street and the dyno. If I had to pick one carb among the 4 to use on our modified engines, which I had to, the Mikuni had a wide range of advantages which included the ability to easily tune for near optimum economy, power, and throttle response in one carb.

6) I'm not the only one turning to the Mikuni, do a little research if you have other questions.

7) When I offer a part or system, I do it openly. I let others try it and report the results. If it doesn't work as I think it does they can send it back and that's it. Phil of Vclassics is going to get a set to try in place of a set of DCOE webers on his 122. Shayne from IPD wants to try a set on his 122 inplace of a set of HS6 SUs. I'm sure you all will here what the results are one way or the other. And that will be a lot better than wasting any more time reading what people have to say about them who have never even seen one.

8) The Mikuni can be, and has been ganged into dual and 4 barrell versions to replace weber DCOE carbs on those manifolds and will flow more, support more HP, and normally give better fuel mileage in those applications. I wish I could get away with a set on my 1800 vintage racecar.

9) The Linx manifold is interesting, but I have not seen any data ( dyno tests, etc.) to show that you can get more power, economy, etc, using that manifold. The disadvantages are not only vastly unequal length runners but also the number of right angle turns in the runners. I bought one just to test it, but haven't had the time yet and only believe something when I can see the test results.

10) I replaced the stock carb on my 360 Husqvarna motocross bike with a Mikuni in 1970, so I'm not exactly new at this. And that carb wasn't anything like the flatslide Mikuni we are talking about now.

John
v-performance.com