Ironhead stroker with electric start???

[Luke Nosewalker]

We're putting a starter on a 76' sportster and I was curious if the stock sportster starter would work with a stroker motor? Does it have enough balls? Or do I have to suck it up and buy a hi-torque starter?

[rukwikenuf]

ya know, i was thinking about this since you sent me that PM.....i don't think that it'd matter. mind you, i am no pro, and i am on my first Ironhead, but it seems to me that the starter shouldn't have to work any harder with a stroker motor if the compression is still close to stock. if you have upped the compression, i'd say try the one you have...........then maybe get the hi-torque one.
just my .02

[Larry T]

I'll agree, if you have a stock starter try it first. But if you don't have anything to start with, I'd buy the high torque starter to begin with. A lot of early Harley starters were pretty marginal even on stock engines.

[Luke Nosewalker]

Did you get a chance to check out that starter?

Originally Posted by rukwikenuf

ya know, i was thinking about this since you sent me that PM.....i don't think that it'd matter. mind you, i am no pro, and i am on my first Ironhead, but it seems to me that the starter shouldn't have to work any harder with a stroker motor if the compression is still close to stock. if you have upped the compression, i'd say try the one you have...........then maybe get the hi-torque one.
just my .02

[Destralo Roach]

Just so ya know, it takes the stock starter every thing it has to start a stock Ironhead, the same for shovels! so if you modify the motor, you should get the best starter you can, and get a gellcell bat or one of H-D's AGM bats for the amp load, as the acidcore bat will puke acid out of the breather tube when you start the bike!

[rukwikenuf]

naw, haven't gotten it wired yet. i think im gonna swap frames and finish up that gas tank before i bother wiring anything. truth be told, i rue the day that i have to wire that bike, electrical diagrams and me don't mix!

[triumphead]

I have a ironhead stroker and a allballs starter doesn't even turn it over !!!

[Destralo Roach]

Originally Posted by triumphead

I have a ironhead stroker and a allballs starter doesn't even turn it over !!!

well maybe you need to back off the timing or install compreleases....

Roach.

[shovelinit]

I have a 96" shovel and a stock starter, unless the timing is way far advanced I dont think there would be a problem. Imo

[waiteitei]

Originally Posted by Luke Nosewalker

We're putting a starter on a 76' sportster and I was curious if the stock sportster starter would work with a stroker motor? Does it have enough balls? Or do I have to suck it up and buy a hi-torque starter?

Short answer is yes it will work

The standard starter motor is the same as on a big twin so if will spin over a 1200 or 1340 big twin a 74" stroked iron head should be ok

However if you are running hi comp pistons it will be at its limit, you will need motor to be in perfect working order and a good battery to make it happen

Have 74" stroker kit in my 77 sportster and the standard starter motor starts it ok

[Rusty-Shackleford]

There is not much value in comparing starting a big twin and a sportster.

Do you have a already kicker on this Sportster? If so, kick and push the button at the same time. You will be surprised at how well this works.

[waiteitei]

Originally Posted by Rusty-Shackleford

There is not much value in comparing starting a big twin and a sportster.

they have the same solenoid and starter motor so the ability of the starter motor to turn over a 1200/ 1340 motor compared to a 1000 motor stroked to 1200 is possibly a very valid comparison

however if there is logic behind your statement ie primary drive ratios or compression ratios I would be interested in finding out.

[bobscogin]

Originally Posted by rukwikenuf

ya know, i was thinking about this since you sent me that PM.....i don't think that it'd matter. mind you, i am no pro, and i am on my first Ironhead, but it seems to me that the starter shouldn't have to work any harder with a stroker motor if the compression is still close to stock
just my .02

The laws of physics would argue with you on that answer. An engine is an air pump. When you increase the displacement, you increase the *volume* of air it's pumping even if the compression ratio hasn't been increased. That's more work being done and that means more horsepower is required out of the starter. I'm not saying the stock starter won't work, just saying that the laws of physics require more power out of it.

Bob

[waiteitei]

Originally Posted by bobscogin

The laws of physics would argue with you on that answer. An engine is an air pump. When you increase the displacement, you increase the *volume* of air it's pumping even if the compression ratio hasn't been increased. That's more work being done and that means more horsepower is required out of the starter. I'm not saying the stock starter won't work, just saying that the laws of physics require more power out of it.

Bob

exactly right, on freshly rebuilt motor before it is run in the standard starter motor will struggle, however once motor is run in and friction from new bore / rings has settled down the standard motor will suffice if everything is in order, ie decent gauge starter wires , batter in good nick and starter motor working as it should

[rgf]

Originally Posted by triumphead

I have a ironhead stroker and a allballs starter doesn't even turn it over !!!

change the cams to ones with more overlap then you can start it with electric starter and it gets more hp.

[Destralo Roach]

Witithgit.. the shovel pistons are way different than a Ironhead piston.. one of the reasons why sportys will break your leg rather than throw ya over the bars like a shovel will....


Roach.

[twistedtee]

Originally Posted by Destralo Roach

Witithgit.. the shovel pistons are way different than a Ironhead piston.. one of the reasons why sportys will break your leg rather than throw ya over the bars like a shovel will....


Roach.

WTF

[Destralo Roach]

Have you seen them side by side.. the sporty piston has a very steep angel for the top... think of it sparking before top dead center... the bang hits the front of that hill and pushes the piston backwards Fast!!

Not so bad on a high comp shovel.... Hence why I retard the timing on the sportys.....

Roach.

[waiteitei]

that is an inherent fault of a hemi head with hi comp piston, which is why twin plugging is so effective on these types of engines, all of the fuel mixture is being ignited at the same time rather than one side of the cylinder being shielded from an offset sparkplug by the piston crown

[flatman]

isn't there a piston porting thread on here or am I remembering it somewhere else?