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Discussion in 'General' started by bigkelk9, Oct 4, 2017.
Cut the cylinders and put the .600 cam in it.
I made the fixtures to cut these cylinders properly.
Correcting the rocker boxes here in this video.
Honing the cylinders with a deck plate and a base fixture in my Sunnen 616.
So tell me, I haven't heard one positive thing about the 600 yet, what do u find better about it then the 585 that I think I'm going to go with.. last minute game changers?
My bike rocks. At a roll in first gear it will hike up the front wheel and carry it. It's insanely fast.
If you want any power out of these engines, you must cut the cylinders.
You're hearing from people that have no clue and understanding about how camshafts work with compression and other variables.
From what I’ve been reading, the 585 is great if you aren’t upping compression. It has less overlap giving you more dynamic compression. Now, if you cut the cylinders down and run the 585 you may have pinging issues due to the lack of overlap. With the raised compression, the 600’s extra overlap brings the dynamic compression back to a safe level for pump gas, and makes use of the extra static compression with more lift/duration.
There may be something there, I know shit but I remember few years back in AR when it was seriously hot, I rode a long day and have shaved cylinders and 585, I had to kill the engine with gear... bloody diesel K9.
Andy, should I now go 600 after your mods too?
....I said he would have to cut the cylinders if he wanted to go with a 600. Since he already boxed them up and never measured the deck height it's a little hard to cut them when he doesn't know by how much.
Very impressive and I also would love to see a K9 riding a wheelie! Wow! How kool is that!
That sounds about right. If you could have pulled a degree or two of timing, it probably would have helped. Although these big twins aren’t my area of expertise, cam theory is the same for all internal combustion engines. I was actually shocked at how few cam options there are. I’m used to Chevy big and small blocks that have literally tens of thousands of options available. Woods has some neat cams, but most of the ones I have looked at have some pretty aggressive ramp profiles. Mix that with the offset rockers on these big bore engines, and you have potential problems. Mainly just excessive wear, but aggressive ramp profiles are harder on springs, pushrods and valves and seats as well as the rockers. Most of the S&S cams seem to be fairly gentle on the valvetrain though.
I could talk cam theory all day, but it looks like you have a pro who knows his stuff handling your parts. Let him know what you want and take his advice.
These pistons are .048 to .052 in the hole. That is ridiculous. There are some serious gains by reducing the piston to deck clearance and tightening up the quench. From memory these engines in the Big Dog frame as they came from Big Dog are 9.52 with a .039 gasket. By bringing the deck clearance to around .005 rather then .052 and using a .035 gasket, it drives that compression ratio to 10.77, and with the 600 cam and premium fuel, they do just fine. It's the camshafts intake events that bleed off the cylinder pressure, and as always your camshaft events should match your compression ratio.
Tapio, your heads and cylinders where in my shop, although I did not have your short block in my shop. When we spoke, you mentioned to me that, "you think that they might have been cut, but wasn't sure". When I picked up the heads and cylinders, your k9 was already at your local motorcycle shop. I never cut your cylinder bases.
To answer your question, I would definitely need to know where the piston sits in relation to the top of the cylinder when the piston is at tdc. This can simply be done by removing the front cylinder head. You can re-use the Cometic gasket that is on your engine.
Just for future reference, when you see something posted by SMCT, you stand at attention and listen to what he has to say. This man knows what he's talking about.
Did you catch the last paragraph in that reply? Not many people get the “pro” title and even fewer get the straight up “take his advice” recommendation from me. Even fewer that I don’t personally know get that recommendation. There is a lot of respect from me in those two sentences.
In with ya...tighten up the quench. Hopefully some day I'll do that.
These S&S motors we have are EPA so they did detune to pass them.
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I'm guessing you use the MLS Cometic Gaskets?
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I am on a deep discount with Cometic and the head and base gaskets for these S&S engines are cheap in comparison to what we use in the shop, so I bought a bulk of different head gasket thicknesses. The base only is offered in one thickness which is .019. That will allow those who don't want to take the cylinders up and off, to just replace their current .039 head gasket with a .023 or a .027 head gasket.
It wasn't a thing about making a business out of it, or making money on it. It was more or less that I could help others with their problems and frustrations, and have the parts to ship to them if need be. These engines are quite simple. Not to much to them. One simple philosophy and you'll be on the right track and enjoying these motorcycles. They are stunning looking bikes, and once you get a few things taken care of (faults of poor engineering decisions) you will be very pleased.
If you haven't changed out the factory gaskets at this point, you will be. The factory garbage base gasket tends to blow out and distort (Oil leak at cylinders base). It's apparent that any way Big Dog could cut corners, they did. Very unfortunate.
Okay; I have a 2000 Bulldog with a 107" and a 600cam. Should I be looking at a base gasket change and/or a tighter quench.? Any problems I should expect.?