How tall are the Pistons on a Shovelhead 74?
The 74″s are 3 7/16″. The 74’s can be bored to 3 1/2″ but I think that the height of the cylinders is slightly shorter. This could be addressed with shims or by getting a set of 80″ jugs to match the 80″ pistons. The pistons come in “low compression” (7.5:1) and “high compression” (8:1). I have the low compression in mine and I prefer it.
Are there aftermarket cylinders for a Shovelhead?
Aftermarket cylinders are available in 3 1/2″ and 3 5/8″ from places like S&S and Custom Chrome. If you go to 3 5/8″ you would have to bore the crankcases to take the extra bore.
Is the V-twin Shovelhead 74 or 80 the same?
The cylinder heads are the same except that heads from 80`s haven`t got any cooling fins on top (between the rockerbox) and all heads from 1974 on utilize long reach threads. I know cause i got one short thread 1972 motor and OF COURSE I`ve had to repair these darn threahs already grrrrrrr
How big is the crank on a Shovelhead?
S&S makes cranks for the Shovelhead too. You will need to address the issue of cylinders as well. The 80’s are stock at 3 1/2″. The 74″s are 3 7/16″.
What causes a Harley Davidson engine to ” fire “?
The engine is still spinning but the incoming fuel rate is very low, until just enough builds up in the combustion chamber to “fire” on the exhaust stroke of the engine. Don’t “change the plugs” like some people suggest, it’s a waste of time and money.
What was the problem with my Harley Davidson?
After about 15 mins she showed up and said her bike would not stay running. At each stop, it would stall but would always start after the fact. It died in the driveway. We tried to troubleshoot the problem but have been unsuccessful so far. Checked the fuel pump, getting gas, changed the plugs and checked the wires for leaks, no leaks.
Why is my fuel pipe popping on my Harley?
Because most aftermarket pipes produce “lower back pressure”, to add to the popping; aftermarket pipes also tend to lower back pressure this will cause the fuel/air mix to lean out. So don’t worry about that popping you sometimes hear and enjoy this year’s riding season.
How can I reduce the popping on my Harley?
You can reduce/ remove the popping by adding fuel percentage to the tune. If you have a Harley Race tuner then any dealer can do this be adding 5%-10% extra fuel. This will decrease your fuel range and also cause your spark plugs to need to be replaced more frequently.