So, I just picked up the 84 CRX mentioned in another thread and got to thinking about adding a little more power.
I had this thought that motorcycle carbs might be a good idea.
So, my questions are:
I'm not looking to gain a ton of power, just wake up the engine a little.
BTW, the engine in the CRX is the 1.3L
44mm Mikuni carbs rock on a stock or very mild 12a rotary.
End of my knowledge on this subject/
Check redpepperracing.com. There swhould be lots of info there. It's a dedicated CRX site.
Todd
I would imagine the carbs from a Yamaha FJ1100 or similar big bore inline 4 bike would work and give you some excitement.
I have six Mikuni 44mm carbs on a Datsun 240Z.
One issue with MC carbs on a car, is getting proper mixture enrichment from idle, resulting in stumble. Carbs like SU and ZS accomplish this by damping the rate at which the mixture piston rises, briefly enriching the mixture. But MC carbs are typically some variation the slide throttle theme, ie, no accel pump, and no floating mixture piston. A MC is light compared to a car, so it's not a big issue. Careful jetting in car applications can overcome some of this, the lighter the car, the less the problem.
Carter
I have a really good bike-carbs-on-a-car-engine article from the Britsh magazine, Practical Performance Car as a pdf file. I'll email you the article if you want.
BTW they recommend Yamaha R1 carbs in the article
M030 wrote:I have a really good bike-carbs-on-a-car-engine article from the Britsh magazine, Practical Performance Car as a pdf file. I'll email you the article if you want.
BTW they recommend Yamaha R1 carbs in the article
That would be great. Send it to clemsonjwd04@yahoo.com
done
M030 wrote:done
Got it. Thanks.
club4ag.com has some recommendations on putting bike carbs on a 4AGE toyota that might help(pics too). My understanding is almost anything 600cc and up will work. Do a CFM proportion in relation to red line(Ie, 600cc X 13K rpm compared to 1300cc and 7K redline). I always figured smaller (like 33mm or so) would be better, but have no data to back up my hunch.
Watch the CFM as noted earlier. Lots of late bike carbs have accelerator pump circuits to overcome the stumble issue. The Mikuni flat slide units from many late 4 stroke dirt bikes not only have accelerator pumps but linear throttle position sensors as well, meaning you can now go with 3D ignition mapping.
If I remember my old honda knowledge, putting Honda motorcycle pistons from a I think it was a 1100 cc honda into that engine, will bump the compression ratio nicely too.... Might want to confirm that with someone more into hondas though.
Chris Rummel
Rumnhammer wrote:If I remember my old honda knowledge, putting Honda motorcycle pistons from a I think it was a 1100 cc honda into that engine, will bump the compression ratio nicely too.... Might want to confirm that with someone more into hondas though.
Chris Rummel
I believe you're right. However, I'm looking to pull the egine right now. Good reminder for a later mod though.
aussiesmg wrote:44mm Mikuni carbs rock on a stock or very mild 12a rotary.
End of my knowledge on this subject/
Aussie, or anyone else, any more details on MC carbs for a rotary? Links? M030, I'd love a copy of that PDF.
96DXCivic wrote:I have six Mikuni 44mm carbs on a Datsun 240Z.
???? the Mikuni's are singles? or do you mean you have 3 - 2 throat mikuni's???
Yes. Mikuni has single carbs as well. You're thinking of automotive carbs.
www.prirace.com is another guy with extensive experience putting moto carbs on car engines. The set-ups aren't cheap, but you're paying for his set-up knowledge. He used Mikunis for single-carb conversions (replacing the Zenith Stromberg on a lot of LBC's) and Keihins for mutli-carb set-ups.
In reply to Jeff:
Send me a PM and I'll send you the article. Or, my email address is, Dimetres AT gaxcars DOT com.
Anybody else who wants the article, feel free to send me a message and I'll send it along.
Maybe it's time GRM explores the topic with an article?
M030 wrote:Maybe it's time GRM explores the topic with an article?
+1
These look interesting:
http://www.v-performance.com/products/air_fuel.html#mikuni_carbs
