cavracer21
Active Member
are bigger springs required for the .600 cam?
bigger springs with .600 cam?
- Thread starter cavracer21
- Start date
Chopper Dave
SIICK!!!
I know Gas runs the .640 springs......with his .600 cam......when I get ready to do the .600 cam next year......I am going to go with the .640 springs also....:up:
It depends.....my 06 with S&S rockers was ok to run .600 lift according to big dog corp. If I pulled off my heads to put on the .640 springs I would definitely shave down the cylinders or buy the shorter true 117 S&S cylinders. I would check the springs and if in doubt put in the .640 springs.
jwoolf
Well-Known Member
Does anyone know how much you can safely take down the cylinders? I guess the compression was like, 10.2:1 on S&S vs. our 9.6:1.
Can we take our further down than that to like 11:1 or 12:1?
I'm not ready to do it just yet but, I will at some point do one or the other. Also, who are the guys really familiar with doing this stuff etc.
I guess for now, I'll add the .600 and leave the rest alone till I do all of it at once. I think I'm going to leave my springs till I do all the head/cylinder work at that point, I'll change everything out.
If I were you and I was only going to do the cam and not head work, I'd change the springs too but, if you're thinking about doing something else later, you may or may not want to consider doing all the other stuff at once.
The 640 springs are meant to go with the .600 cam so, they're the right thing to use; however, the word is that you can get by just fine without them too so, for me, I'm going to just drop the cam in for now and do the rest down the road. ( at least till I change my mind again ) LOL
Can we take our further down than that to like 11:1 or 12:1?
I'm not ready to do it just yet but, I will at some point do one or the other. Also, who are the guys really familiar with doing this stuff etc.
I guess for now, I'll add the .600 and leave the rest alone till I do all of it at once. I think I'm going to leave my springs till I do all the head/cylinder work at that point, I'll change everything out.
If I were you and I was only going to do the cam and not head work, I'd change the springs too but, if you're thinking about doing something else later, you may or may not want to consider doing all the other stuff at once.
The 640 springs are meant to go with the .600 cam so, they're the right thing to use; however, the word is that you can get by just fine without them too so, for me, I'm going to just drop the cam in for now and do the rest down the road. ( at least till I change my mind again ) LOL
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Black Dawg
Active Member
My 07 came with dual red stripe springs. I suspect these are the 640 springs without the 3rd spring (probably deemed overkill with the stock lower lift cam). I'm running the 600 without issues with this spring.
As far as how much to take down the jugs, you really need to measure your deck height to determine that. But it's about .040 or .045. Getting it close to zero deck will bump compression to 10.5:1, which is about the limit for pump fuel using the 600 cam.
The 640 cam needs even more compression however. To achieve that you'll need to mill the head too. You might be able to run pump fuel with this combo since the 640 will bleed off some cylinder pressure.
As far as how much to take down the jugs, you really need to measure your deck height to determine that. But it's about .040 or .045. Getting it close to zero deck will bump compression to 10.5:1, which is about the limit for pump fuel using the 600 cam.
The 640 cam needs even more compression however. To achieve that you'll need to mill the head too. You might be able to run pump fuel with this combo since the 640 will bleed off some cylinder pressure.
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cavracer21
Active Member
thanx for the advice guys, just picked up a cam off ebay for $100.
The 05 bikes are the ones with suspect springs I think and I thought 06 with TP rocker boxes. Not 100%. You would not want to go to 11:1 and definitely not 12:1. The stock 117 compression of 10.2 is ideal for the .600 cam.(I guess thats why S&S made it that way.
When and if I do it I will take big dog cylinder specs and subtract S&S specs and mill them that amount or just buy new jugs whichever I think is the best route.
jwoolf
Well-Known Member
My thoughts were to just drop the cam in for now. If I do need the springs, I'll do that too but, I guess my initial thoughts were to not worry about that yet.
What I'd planned on doing is waiting till I need a top end and just shave the jugs and the heads and change the rockers and lifters and port and flow the heads. Hone and change the rings and at the same time drop the .640 or something else that will turn on at that compression ratio.
I read today somewhere that on the stock cyl you have .55 on our bikes and, it's .15 on the S&S. If that is true then by taking .40 off the jugs, you'll end up with the S&S 10.2:1 compression. At that point you can go more by shaving the heads too. How much, I don't know yet.
I also read that the S&S lifters are suspect of oil flow and should be changed out if you have the chance.
Please tell my if I'm full of shit but, that's the info I got so far.
What I'd planned on doing is waiting till I need a top end and just shave the jugs and the heads and change the rockers and lifters and port and flow the heads. Hone and change the rings and at the same time drop the .640 or something else that will turn on at that compression ratio.
I read today somewhere that on the stock cyl you have .55 on our bikes and, it's .15 on the S&S. If that is true then by taking .40 off the jugs, you'll end up with the S&S 10.2:1 compression. At that point you can go more by shaving the heads too. How much, I don't know yet.
I also read that the S&S lifters are suspect of oil flow and should be changed out if you have the chance.
Please tell my if I'm full of shit but, that's the info I got so far.
jwoolf
Well-Known Member
Ok, cool, so what replacement parts did you use, I'm sure you changed everything out. I'd like to not to have to re-invent the wheel here. I know your set up works. Man, I'm tryin' to get to where you've already been.
Also, where to I send the jugs and heads when I pull the stuff?
See, I have the ability to do this in March but, I'm not sure I'm going to do it all right now. I've got other stuff to do to it too. I'm looking to get the low fruit right now. I should be able to put a .600 in it now but, I have plans for other stuff.
I've got to buy the OL a Harley this March.
Nomad2day
Longhair Redneck Geek
Perhaps someone can answer this question for me.
On the 07 Bulldog EFI models, I think they only have a single spring and have no idea what lift they can handle. I have not opened mine up to see yet. I think the stock cam in these bikes are only a .536.
Can someone shed some light on this for me.
Thanks,
Neil
On the 07 Bulldog EFI models, I think they only have a single spring and have no idea what lift they can handle. I have not opened mine up to see yet. I think the stock cam in these bikes are only a .536.
Can someone shed some light on this for me.
Thanks,
Neil
Chopper Dave
SIICK!!!
I thought the stock cams for the 06 and 07 models were .569 comp cam...
I think only the EFI models are different.
Chopper Dave
SIICK!!!
oh.....gotcha Ray....I think only the EFI models are different.
Black Dawg
Active Member
Neil,
You are correct. The EFI bikes appear to have come with the new S&S "Sidewinder" single coil "bee hive" type spring. I believe max lift is only .580 or so. If you pull the valve cover off they are easily identified by the small valve spring retainer.
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