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jt351
16th December 2006, 09:35
Hey guys just wondering if anyone makes a conversion valve for my 2005 883 sportster. I went to my local harley speed shop at first they said yeah, then they called me and said no unless I want to change guides, springs, retainers, keepers etc. I also was doing some searching on here and it was stated that rowe does not make either. Does anyone know who makes 7mm conversion valves. Also the speed shop said that it was stupid to put my bolt-in se .497 cams in without valves cause I cannot take advatage of it, I,m sorry but more duration is more duration, making more use of my smaller valves by holding them open longer.

cootertwo
16th December 2006, 11:51
Yes, Manley, or somebody, does make larger valves for 883 heads. You can get them the same size as 1200, but they are longer, to fit in the 883 heads, without any other modification. Of course the seats have to be changed, and porting would be in order. Check out a J&P catalog, maybe that's where I saw them.

maddog
16th December 2006, 12:26
You should be able to find them by Baisley in the Zippers Catalogue.
www.zippersperformance.com

Gone
16th December 2006, 13:38
Welcome to BEST sporty forum on the internet!

Rowe does make the conversion valves for up to 2003 heads, I know. There have been replies from NRHS on the subject; you might do a search to find the responses.

I have the stock valves in my conversion with N4 cams; I'm happy with the performance.

aswracing
16th December 2006, 15:09
I'm not aware of anyone offering 7mm conversion valves. I went looking for them awhile back and no one had them, so if someone has them now, it's a more recent development.

We could probably come up with them as a new product, I'll look into it. We don't get a lot of call for it because bigger valves are a part of Stage 2 service, and stage 2 service includes all new springs & retainers & guides anyway, so we convert'em to 5/16 stems. But still, it'd be a good product to have.

Keep in mind that you won't be converting to the 04-up 1200 valve diameter, you'll be converting to the 88-03 size. The 04-up valves are larger and they won't fit without a lot of surgery to the head (new seats and considerable sinking, unshrouding, etc).

Intake valve diameters:
883's (all): 1.580"
88-03 1200's: 1.715"
04-up 1200's: 1.810"

Exhaust valve diameters:
883's (all): 1.350"
88-03 1200's: 1.480"
04-up 1200's: 1.575"

The 04-up 1200 valve sizes are too big for the 883 seats, and also there's no room for the valve heads unless you sink them back to normal 1200 depths (883 have a shallower chamber and use a longer valve to match, and the valve heads will get together with large valves). So installing them involves quite a bit of work. 883 heads will accomodate the 88-03 valve sizes on their original seats, though. Be sure to cut out the seat i.d. when you do the valve job or you'll get no benefit from the bigger valve. The valve size isn't what adds flow, it's the size of the hole, all the valve does is plug the hole.

cootertwo
16th December 2006, 15:20
http://www.jpcycles.com/productgroup.aspx?GID=0A6E2335-5FD5-4ECC-ACA5-39D5A4E6444E

jt351
16th December 2006, 20:05
Thanks guys, that's what I thought. So If I don't upgrade valves what part of the heads should I work on to improve them. My machinist said he would clean up the bowls and smooth out the guides. Any particular area to pay attention to for best results, I'm not going all out, or I would have spent $$$ on good heads. Also what are peoples suggestions on starting out on jet size, It still has stock slow and main jet, with a dynojet needle. I believe 45/170 Thanks
specs 1200 conversion, 10:1 cr, se.497 buell cams

Gone
16th December 2006, 21:16
Also the speed shop said that it was stupid to put my bolt-in se .497 cams in without valves cause I cannot take advatage of it, I,m sorry but more duration is more duration, making more use of my smaller valves by holding them open longer.

I get real tired of "sales counter secretaries" at so-called speed shops, giving out half-baked info. Obviously to get the most out of cams, big valves help and porting helps and compression helps and bigger carbs help and air cleaners help and exhaust helps and bigger bores help and stroker cranks help - but the cams themselves WILL flow more air. However, on stock engines, one can not go big or all of your low-end and mid-range will go out the window. A mild set of drop-in cams can be an easily installed first step, before digging deeper into the engine for further gains, such as the NRHS stage 1 or 2 porting and the possible big bore kit.

Pick a REPUTABLE firm such as NRHS or Carpenter then tell them your projected plans. They will give you straight-up advice on how to best do it step by step to ease wallet strain and to get some additional wear and tear on your already paid-for, stock components. The majority of speed shop secretaries only know what the advertising hype in the literature and pics tell them.

cantolina
17th December 2006, 00:13
Hey guys just wondering if anyone makes a conversion valve for my 2005 883 sportster. I went to my local harley speed shop at first they said yeah, then they called me and said no unless I want to change guides, springs, retainers, keepers etc. I also was doing some searching on here and it was stated that rowe does not make either. Does anyone know who makes 7mm conversion valves. Also the speed shop said that it was stupid to put my bolt-in se .497 cams in without valves cause I cannot take advatage of it, I,m sorry but more duration is more duration, making more use of my smaller valves by holding them open longer.

Ahhhhh....

Once again the old "velocity vs. volume" discussion...

.497's are pretty mild.....keep the velocity versus the volume unless you plan on a good deal more work (conversion, headwork, etc.)

jt351
5th January 2007, 12:27
Well I went for it, bought 03 conversion valves guides springs etc etc, my old valves showed a lot of wear so I went for it. I am getting all the work done with porting for 200$. work is slow around the machine shop and I told him to take his time ,oh and it was cash too. The conversion valves are slightly shorter than my stock 883 vales, he said it can be fixed w/ lash caps, but then he was telling me I will need adjustable pushrods, I don't see why as long as I can get valve tip to the original height. anyone done this type of conversion??

jt351
8th January 2007, 19:19
Also Anyone know what kind of seat pressure I need, I am using comp dual springs w/ chromoly retainers and they are good for .6 lift, not sure of the number. but my machinist was going to cut the seat to get it down to 125lbs seat pressure, is that low, I am runnin 497 se cams. thanks

Shu
8th January 2007, 19:53
I thought Kibblewhite made Black Diamond valves for this application.
http://www.blackdiamondvalves.com/Harley_Davidson.pdf


Jetting? Start with a 45 slow jet, 185 main with your dynojet kit. Then you might have to tweak on the needle height to fine tune. With these cams, you are going to want an exhaust that is good at fighting reversion.

aswracing
8th January 2007, 22:10
Nope, they don't have them.

They have stock replacement 04-up 883 valves (7mm stem, 1.580 & 1.350 diameters). And they have the older 883 to 1200 conversion valves (5/16 stem, 1.715 & 1.480 diameters). But not the new stem size in the old 1200 head diameters. Nobody has them, nearly as I can tell. The only way to do it right now is to convert to 5/16 stems, or pay big bucks for custom valves.

Shu
8th January 2007, 22:14
Are the new valve guides the same OD as the old ones? Is this as easy as switching guides? Or do the heads require machine work to fit the new guides?

jt351
9th January 2007, 03:16
they are the same size, he's already got the new/oldstyle guides in and now he's porting them, but my question was has anyone done this and still use stock pushrods? anyone know correct seat pressures? What kind of exhaust is good at fighting reversion? I have gutted Harley pipes with the crossover, I love how it sounds quiet cruising and loud when gettin on it.

addertooth
15th January 2007, 15:06
I gave a look at conversion valves. They are 60 thousandths shorter than standard 883 valves. This shorter length allows the valve seat to be cut deeper to accept the 1200 size valves. If he cuts your valve seat at least 40 thousandths you will only have a 20 thousandths variation in your push rod positioning which is within the limits of what a stock hydraulic lifter can make up. Now for the bad news. The valves are not in the same physical position on an 883 head as they are a stock 1200 head. This means on a high lift/duration cam you have to check valve/piston clearance in the assembly process and make sure you are not heading for a collision. Some people have had to fly cut the valve pockets on the piston crown to ensure an acceptable amount of clearance. Be sure to clay the top of your pistons, this will tell you the story. As far as spring pressure, 125 is stock pressure. But there is nothing magical about this number. Your hydraulic lifters and push rods will accept more, within limits. Look at the screaming eagle catalog at the performance springs they sell, and stay within the seat pressure they advertise. Keep in mind higher spring pressure translates to higher wear on your cams and valve train. It also translates to higher rpms without float becoming a critical issue. My stock valve train spins 6500 rpms just fine with .5 lift 264 degree cams, so how high are you planning to go? Addertooth

jt351
18th January 2007, 09:21
Well I did not clay my pistons, I am using screamin eagle arias forged pistons, they had a decent relief in the reverse dome area, So I assumed there was clearence with my bolt in cams ie the term bolt in cams. they are the .497 cams actually they are out of a 2001 s1 buell, My machinist checked before and after height and added lash caps to come up with the same height, I have not fired it yet cause it is 17 degrees out now and can't go for a run, but It cranks over with no clearence issues, no knocking or bangin, I got my fingers crossed, But sinced I fix Fords for a living I don't think the harley will be a problem.