How much can I expect?

[Mindless]

I suppose this question is directed at you guys who have built a couple of 1150 engines in your days (Ray among others).

As you may or may not know, I'm doing some winter upgrades on my EF. Cylinders have been bored up to 77mm to accept a 1230cc 10.25:1 Wiseco piston kit. Cylinder has been skimmed about .2mm to get a nice and smooth surface. And the head is currently in England at Roger Uppertons place getting a makeover with a nice race port and bigger valves as well as re-cut valve seats and a 1mm skim.

So the spec of my engine will be as follows:


Keihin FCR39's with 35mm velocity stacks. Set up pretty much perfectly (Erik Marklund of MC Xpress commended me on it), only need a few steps down on the main jets.

WebCams .348" set at 108 degrees on both IN/EX.

Full race ported head with a 1mm skim, 29.5mm intake valves, stock exhaust valves, competition valve job (recut seats).

1230cc bore with 10.25:1cr (around 11-11.5:1 with the skim of the head and cylinder).

Complete DYNA2000 ignition system with grey coils and suppressor wires.

40mm stainless 4-1 exhaust.


How many ponies could I expect? When talking with Upperton he seems quite confident that this setup could make up towards 150-155 horsepower at the wheel, maybe even more. What do you think about that estimate? Exaggerated or fair?

I won't be disappointed if the bike makes just 145rwhp since it made 125.51rwhp with 70000 miles in it. Only performance mods I had done then was new valve seals, a quick clean of the valve seats, new cams and new carbs.

[rapidray]

It should be somewhere between 145 & 155 hp at the rear wheel. Also, if you are street riding this bike, you would be better off with the cams at 106 int. & 108 exh. MUCH stronger midrange & better scavenging. Ray.

[Mindless]

It should be somewhere between 145 & 155 hp at the rear wheel. Also, if you are street riding this bike, you would be better off with the cams at 106 int. & 108 exh. MUCH stronger midrange & better scavenging. Ray.

Kind of what I've suspected then.

As for how I ride it: it varies. It will probably see a good 10 days on the track in the coming year. I'll be riding it on the street mostly though.

I've been thinking about altering the cam timing since the overlap is massive right now with the duration on these cams. I was experiencing some trouble in the higher gears with the bike losing power, would rev to the red line in all gears but 4th (only up to 8500ish) and 5th (5000ish).

Naturally the stock head restricted the engine a lot but I suspect the cam timing played a big part too.

Anyway, thanks for your input Ray.

/Viktor

[posplayr]

Kind of what I've suspected then.

As for how I ride it: it varies. It will probably see a good 10 days on the track in the coming year. I'll be riding it on the street mostly though.

I've been thinking about altering the cam timing since the overlap is massive right now with the duration on these cams. I was experiencing some trouble in the higher gears with the bike losing power, would rev to the red line in all gears but 4th (only up to 8500ish) and 5th (5000ish).

Naturally the stock head restricted the engine a lot but I suspect the cam timing played a big part too.

Anyway, thanks for your input Ray.

/Viktor

I usually don't run to redline, but doing my recent jetting escapades, I was going over 9500+ in 4th on a 6% grade (uphill) and I was not letting up. 1166, 95 cfm ported head, 0.340's, 4:2:1, 105/107, 36mm CV's ; 210 lbs in birthday suite but has full gear on.

You thing that is due to cams?

[Mindless]

I usually don't run to redline, but doing my recent jetting escapades, I was going over 9500+ in 4th on a 6% grade (uphill) and I was not letting up. 1166, 95 cfm ported head, 0.340's, 4:2:1, 105/107, 36mm CV's ; 210 lbs in birthday suite but has full gear on.

You thing that is due to cams?

Large cam overlap can do a lot of things but I suspect that the head and exhaust are the main culprits.

The exhaust ports on the EF head are notoriously tiny. My middle finger struggles to get into the port and thinking what a small hole like that has to breathe at 9000rpm. Well, it just doesn't work. Added to that a set of 35mm downpipes, it's possible that the resistance is so big on the exhaust side of the engine that it just can't rev higher.

We'll see how it preforms after a big port and new pistons. Hopefully these bugs will have disappeared.

[rapidray]

My middle finger struggles to get into the port

Is your finger bigger than your Johnson??? The 1150 exhaust ports are NOT small!!! Ray.

[Mindless]

Is your finger bigger than your Johnson??? The 1150 exhaust ports are NOT small!!! Ray.

Might have exaggerated a bit.

I think they're quite small though.

[headsbikesmopars]

You guys are funny..LOL,LOL.