kiwi303 Posted June 8, 2008 Share Posted June 8, 2008 I was talking with a garage guy recently who buys old bikes and scraps them for parts. he mentioned running a Toyota 3Y engine in a hilux with 4x 600cc bike carbs, one to each cylinder instead of the stock piece of crap autochoke carb toyota fitted them with. That got me thinking, what would a L series motor be like with individual carbs? straight line equal length tubes out to a motorbike side draft carburettor... If two SU's are good, and 3 Webers are better, what about 6 of them? Anyone done this? should I round up a set of six carbs and hook them up? Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted June 8, 2008 Share Posted June 8, 2008 Well, twin throat side drafts like the Mikuni PHH 40s and 44s will get you *basically* the same thing, just a shared fuel bowl. *shrugs*. Sounds like it could be cool, but the problem I see is you might have issues with the throttle linkage (I don't know how bike carbs are hooked up though. Quote Link to comment Share on other sites More sharing options...
skib Posted June 8, 2008 Share Posted June 8, 2008 you could try it and find out lol it will be interesting to see if you do it Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 8, 2008 Share Posted June 8, 2008 Search here and classiczcars.com. There is a guy doing it with Mikuni bike carbs, supposedly better than the PHH series, although as said above, the PHH's are basically 6 carburetors, each cylinder has its own throat and jets. Quote Link to comment Share on other sites More sharing options...
Dat260 Posted June 8, 2008 Share Posted June 8, 2008 I think that guy's name is Eiji, I posted a pic of his set-up. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 8, 2008 Share Posted June 8, 2008 jeeze. "hey wanna go to the beach today? its nice out... lets go for a cruise" --- "nah, maybe next weekend, this weekend im adjusting and balancing my carbs... all six of them" Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted June 8, 2008 Author Share Posted June 8, 2008 Great so it's workable then. I'll have to ask him to save me a set of matching carbs Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted June 8, 2008 Share Posted June 8, 2008 motorcycle carbs are easy to balance. you just need to have two sets of mercury sticks so you have enough but other than that it would be easy. you have to balance motorcycles all the time. and they ahve had 6 cylinder motorcycles actually i think honda had an inline 6 cyl. turbo actually.. Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted June 8, 2008 Author Share Posted June 8, 2008 I know the GSXR series are 4 cyl with 4 carbs. I almost bought an 89 GSXR250R-SP which is the road legal race bike, complete with larger rear wheel and closer gears. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted June 8, 2008 Share Posted June 8, 2008 Almost all bikes have IR carb setups. They generally don't require constant attention, only when the valve adjustment is changed. Most of the 4 cylinder bike carbs might be bit small for the Z engines. The carbs from a 1000cc twin would certainly be large enough. I have been wondering if using 6 of the Hitachi/SU carbs would be worth the effort. Has anyone done this? Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted June 8, 2008 Author Share Posted June 8, 2008 I did a bit of googling. and found details of 44mm and 48mm mikunis for triple carb setups on Z cars, using a bit of maths, one 44mm is slightly less than two 32mm. and looking on trademe it looks like theres plenty of Mikuni 34mm and 36mm carbs available secondhand. I think I'll have a talk to the guy and see if he can score me a set of 6 Mikuni 36mm carbs Beerman, while googling, I saw the mini apparantly used twin SU carbs for the 1100 engine, 6 mini carbs might work as well. Quote Link to comment Share on other sites More sharing options...
Daeron Posted June 9, 2008 Share Posted June 9, 2008 I did a bit of googling. and found details of 44mm and 48mm mikunis for triple carb setups on Z cars, using a bit of maths, one 44mm is slightly less than two 32mm. and looking on trademe it looks like theres plenty of Mikuni 34mm and 36mm carbs available secondhand. I think I'll have a talk to the guy and see if he can score me a set of 6 Mikuni 36mm carbs Beerman, while googling, I saw the mini apparantly used twin SU carbs for the 1100 engine, 6 mini carbs might work as well. the "40/44" is the bore of the choke, which is exactly the same figure as the "36." Basically, you are not recognizing that the 40 or 44 is multiplied by six, even though it is technically only three carburetors. Six 36mm bike carbs < three 40mm double-choke solex/mikuni/weber DCOE Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted June 9, 2008 Author Share Posted June 9, 2008 so what size mikuni bike carbs should I get? I take it then that the webers and mikunis fitted to the Z's as triple carb setups are double units? I was thinking of them as single units that lead into a double pipe to two cylinders. I've only ever owned two carbed cars, one was a twin carb honda prelude, and the other is the current '85 hilux. Never needed to do anything to the carbs, and other than those, everything else has been EFI. I'm a total noobie to carbs. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted June 9, 2008 Share Posted June 9, 2008 so what size mikuni bike carbs should I get? I take it then that the webers and mikunis fitted to the Z's as triple carb setups are double units? I was thinking of them as single units that lead into a double pipe to two cylinders. I've only ever owned two carbed cars, one was a twin carb honda prelude, and the other is the current '85 hilux. Never needed to do anything to the carbs, and other than those, everything else has been EFI. I'm a total noobie to carbs. This is a picture of my triple mikunis: As you can see, Mikunis and many other triple setups are actually twin throat, so in a sense, (like I mentioned earlier), they are basically six carbs, but each pair shares a fuel bowl. Quote Link to comment Share on other sites More sharing options...
Daeron Posted June 9, 2008 Share Posted June 9, 2008 Panzer, could you do me a quick favor??? a few weeks ago I tried looking for a picture of the mikuni logo, as molded onto the jet covers of the carbs, via google image search and couldn't for the life of me find one. The Mikue logo doesn't look the same to me, as the typeface embossed on the carb istelf.. I was wondering if you could snap me a high res image of JUST the jet cover (the spot in between the throats there, where it says MIKUNI and email it to me? shawnmcarey at gmail dot com, thanks in advance. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted June 9, 2008 Share Posted June 9, 2008 Panzer, could you do me a quick favor??? a few weeks ago I tried looking for a picture of the mikuni logo, as molded onto the jet covers of the carbs, via google image search and couldn't for the life of me find one. The Mikue logo doesn't look the same to me, as the typeface embossed on the carb istelf.. I was wondering if you could snap me a high res image of JUST the jet cover (the spot in between the throats there, where it says MIKUNI and email it to me? shawnmcarey at gmail dot com, thanks in advance. Sure, no problem. It'll have to wait till later today, but I shold be able to get them to you today or tomorrow. Quote Link to comment Share on other sites More sharing options...
Daeron Posted June 9, 2008 Share Posted June 9, 2008 awesomeness on a stick, thanks. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted June 10, 2008 Share Posted June 10, 2008 Kiwi, The Weber, Mikuni/Solex and Dellorto carbs typically used on the Z cars are 2 barrel carbs. Typically used in sets of three on 6 cylinder engines. This yeilds one venturi per cylinder. The typical set-up does not cross-connect one cylinder to another, thus it is called an "Isolated Runner" system. The size required depends on the displacement of the engine and the RPM of maximum output. In the book "Weber Carburetors" by Pat Braden there is a chart provided by Weber that shows the carb size required based in individual cylinder displacement and RPM of maximum output for a race engine (for an IR system). This chart indicates that for a 2400cc 6 cylinder engine that has maximum output at 6000 RPM the carb VENTURI should be 33mm. This is for a "race" engine. Street engines will likely want to be a bit smaller. To temper this there is also a chart for a single one-venturi carb on an engine with maximum output at 5000 RPM. In this case the carb indicated for the 2400cc engine is 31mm to 35mm dependent upon application. Regarding the motorcycle carbs, it does not matter that they come from a motorcycle. The size is the size and they will flow a similar amount of air as a comparable quality car carb. Also, since they are constant velocity (as are the Hitachi/SU carbs) it is not as much of a penalty if they are too big (compared to fixed venturi designs). Quote Link to comment Share on other sites More sharing options...
Guest Scooterpat Posted June 10, 2008 Share Posted June 10, 2008 The Mikuni motorcycle carbs shown in the image above are aflat slide, smooth bore design. They are excellent and very tunable carbs. Generally they would be set up for use on an inline 4. For someone with the skills and access to machine tools, making the linkage to set up for an inline 6 would be fairly simple. They use a common throttle shaft running through all of the carbs and a single bell crank for the throttle cables. Be careful about buying six separate carbs like the one in the e-bay listing shown above! That is a different type of Mikuni and is not suitable for use on the manner you guys are talking about. If you are going to buy used carbs off e-bay or similar sites, make sure they are for inline multis and are set up for 4 cycle engines. The one in the post above is from a 2 cycle and will have the wrong basic set up for use on a 4 cycle engine. Quote Link to comment Share on other sites More sharing options...
Guest Scooterpat Posted June 10, 2008 Share Posted June 10, 2008 OOPS! Didn't realize that the e-bay thing is an advertisement that changes to a different item each time I come back to this page. But the part about 2 cycle vs. 4 cycle carb set up still applies. Quote Link to comment Share on other sites More sharing options...
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