| Author | Message | ||
     Harold |
I have had 2 different engine builders give me a different answer. One says it doesn't make a difference in power with twin spark plugs on flat tops, since there is nothing to get in the way of the flame. The other said he has pulled one plug wire off a twin plug, and the bike ran different at idle, suggesting more power was available with twin plugs. Do any of you have any feedback on this? | ||
| Sportyeric |
An engine with twin plugs will require less spark advance (as the spark only has to travel half the distance.) So if you pull one spark plug lead it will idle differently until you re-adjust the timing. A waste of money, as far as I know. | ||
| Sloppy |
For street applications - if you need multiple spark plugs then you have a poorly designed combustion chamber... | ||
| Phelan |
As stated, it's not necessary. My '03 XL1200S had dual plugged lightning heads from the factory, and a fancy ignition, but the same heads were ran from the factory in the '96-'98 S1s (not S1W) with one plug with no problems. | ||
| Harold |
All of you match the answer that the guy who is doing my work also said. The other guy does drag race motors, but not near as many as Wes. I will be posting a dyno sheet in around 2 weeks. | ||
| Phelan |
You talking about Wes at CycleRama? | ||
| Preybird1 |
What is your squish band going to be at? Flat top pistons and what heads?  My bike was done by land speed racers. Please post your dyno sheet i would be very interested in seeing it!  | ||
| Harold |
Yes, I'll be taking it to Wes at CycleRama. I don't know what he is going to do with the squish band, it's all in his hands. The heads right now are stock thunderstorms in my 98 S1W. The before dyno chart is in a recent post of mine, "What's next with my 88ci". It did I think 98.6 ft/lbs, but only 88 hp or so. I am expecting at least 115 hp, but hoping for 120. | ||
| Phelan |
If using the pistons and cyls you already have, most likely the squish will be left alone @ 15* in the stock T-storms. | ||
| Kalali |
Russ, come on, stop bragging... | ||
| Sportyeric |
It took a bit of re-reading. I was going to say that if you have a Thunderstorms heads, you don't have flat-top pistons. However, the 88 inches would be a flat-top piston, wouldn't it. And the squish to be set is the question of how tight, not at what angle. Sounds like a fun ride shaping up. What's a reasonable price to pay for a dyno run or three? | ||
| Preybird1 |
Kalali I not trying to brag sorry. I Was just showing my experience with my build. that 88" will be a monster! I was going to go bigger but i didn't like the idea of the case splitting and the labor\time to remove the motor. | ||
| Harold |
Russ, You have got a real flat torque curve. If you look at mine, it drops like a rock after 4K. After the work, I am hoping to get one like yours, just moved up about 10 ft/lbs, which would yield around 120 hp. | ||
| Kalali |
"I not trying to brag sorry. I Was just showing my experience with my build" I know you are not....I was just pulling your leg... |
