Topic: 550 Larger valves

[xedge4lifex]

Who makes them?
Howell talked about putting in some peugeot or renualt valves in his 500 race bike.
do the cb750 valves fit?
how much and where would larger valves be found?

[bwaller]

Check XL250 valves in the Kibblewhite catalogue. Seems to me one of those is an option.

[DavePhipps]

CB650 head on the 550. Bigger valves, better intake tract. Pain to find pistons with the correct CR though.

[mlinder]

I haven't made a measurement yet, but the wristpin to shoulder height on the 650 pistons is maybe 2 or 3 thou shorter than 550 pistons.

bore 550 jugs to accept stock 650 pistons, possibly deck the jugs, possibly a thin cometic gasket may do it.

Install 650 top end.

Takes you out to, I dunno, 565cc?

Profit.


Just sticking a 650 head on a stock bore 550 will probably give you a 'mushroom' shaped combustion chamber. Probably not the best idea.

We will be trying this at some point over the next year. If we do it before you, we'll let you know how it works.

[turboguzzi]

xedge, maybe tell us what you are trying to achieve?

Larger valves per se wont improve flow unless followed with porting that can make good use of them. In the 500/550 minimum cross section is at the seat ring. To enlarge the seat ID you really need to know what you are doing, the stock seat is the main limit to throat side and not much room to enlarge.

TG

[MRieck]

xedge, maybe tell us what you are trying to achieve?

Larger valves per se wont improve flow unless followed with porting that can make good use of them. In the 500/550 minimum cross section is at the seat ring. To enlarge the seat ID you really need to know what you are doing, the stock seat is the main limit to throat side and not much room to enlarge.

TG

Exactly. You'd really have to change the valve angle to get an oversize seat/valve in there to make a noticeable impact on performance.

[xedge4lifex]

xedge, maybe tell us what you are trying to achieve?

Larger valves per se wont improve flow unless followed with porting that can make good use of them. In the 500/550 minimum cross section is at the seat ring. To enlarge the seat ID you really need to know what you are doing, the stock seat is the main limit to throat side and not much room to enlarge.

TG

i keep hearing about guys installing "larger valves" mainly in harley and trumps. ive seen the difference of a machined seat in a valve job and its awesome. rene had a post about putting car valves in a 550 head. i do ALOT of port and polish jobs, and if im going through the effort to smooth everything out i might as well open things up a bit in the engine too. ive often wondered how the 650 pistons and either dropping the stacks, or machining the 550 stacks to accept the 650 sleeves would be a better option. my 550 is just begging for a hemi head.

mostly the reason would be; busting 110 the other day, and wanting more. top end and acceleration, but thats a completely different topic all together

[turboguzzi]

xedge, maybe tell us what you are trying to achieve?

Larger valves per se wont improve flow unless followed with porting that can make good use of them. In the 500/550 minimum cross section is at the seat ring. To enlarge the seat ID you really need to know what you are doing, the stock seat is the main limit to throat side and not much room to enlarge.

TG

i keep hearing about guys installing "larger valves" mainly in harley and trumps. ive seen the difference of a machined seat in a valve job and its awesome. rene had a post about putting car valves in a 550 head. i do ALOT of port and polish jobs, and if im going through the effort to smooth everything out i might as well open things up a bit in the engine too. ive often wondered how the 650 pistons and either dropping the stacks, or machining the 550 stacks to accept the 650 sleeves would be a better option. my 550 is just begging for a hemi head.

mostly the reason would be; busting 110 the other day, and wanting more. top end and acceleration, but thats a completely different topic all together

OK, didnt know you are a porting pro, if your 550 does 110 with ease then i'd say you have a great motor already... compliments on the work.

if you still after rene's valves maybe try PM him directly for a source in Europe? I doubt if you'll find Renault 16V 1400-1600 valves in the US. Maybe in Canada?

cheers

Tg

[kos]

TTR400 is a member of the forum and he lists valves for CB400F's on his site. he also says he he supply any size valve for any SOHC 4 made if you give him specs and or sample.

KOS

[Kemp]

The 650 pistons are a bit taller from wrist pin to shoulder than the 550 pistons. I bored a 550 block to 61mm to accept a set of Powroll pistons. Thought I would mock up this barrel on a a crankcase with a 550 piston (58.4mm), Powroll piston(60.87) and 650 piston (59.78mm), just to see what the deck height would look like. The Powroll and 550 stocker have the same wrist pin to shoulder height so they come up to just short of the top of the cylinder (base gst installed). The 650 piston comes above the cylinder about 3mm and hits the head (just rested head on top of cylinder). Two issues the high shoulder of the 650 piston hits head square on and the shallow sqiush angle of the 550 head does not match the 650 piston. The piston would need to have the shoulder machined in at shoulder about a mm or so to make it flat to cyl where it overlaps the head. Then machine the piston crown squish angle down to match head squish. The remaining dome would probably raise compression ratio significantly and might need some modification to it as well as valve cutaway depth. Machining would be similar to that needed to use 750K pistons in 550 as in the Gentlemans Express article[/img]. When I substituted a 650 cylinder for the 550 cylinder and placed it on the the 550 crankcase the result was that the 650 piston was way too low in the cylinder because the 650 cyl is about 5mm taller than the 550 cyl and the 650 crank has rods that are 5mm longer than the 550's resulting in the 650 piston being about 8-10mm below top of 650cyl.

[mlinder]

The 650 pistons are a bit taller from wrist pin to shoulder than the 550 pistons. I bored a 550 block to 61mm to accept a set of Powroll pistons.

Odd, the ones I just measured are just a wee bit shorter from wristpin to shoulder.
Of course, wristpin to crown were higher on the 650.

Thought I would mock up this barrel on a a crankcase with a 550 piston (58.4mm), Powroll piston(60.87) and 650 piston (59.78mm), just to see what the deck height would look like. The Powroll and 550 stocker have the same wrist pin to shoulder height so they come up to just short of the top of the cylinder (base gst installed). The 650 piston comes above the cylinder about 3mm and hits the head (just rested head on top of cylinder). Two issues the high shoulder of the 650 piston hits head square on and the shallow sqiush angle of the 550 head does not match the 650 piston. The piston would need to have the shoulder machined in at shoulder about a mm or so to make it flat to cyl where it overlaps the head. Then machine the piston crown squish angle down to match head squish. The remaining dome would probably raise compression ratio significantly and might need some modification to it as well as valve cutaway depth. Machining would be similar to that needed to use 750K pistons in 550 as in the Gentlemans Express article[/img]. When I substituted a 650 cylinder for the 550 cylinder and placed it on the the 550 crankcase the result was that the 650 piston was way too low in the cylinder because the 650 cyl is about 5mm taller than the 550 cyl and the 650 crank has rods that are 5mm longer than the 550's resulting in the 650 piston being about 8-10mm below top of 650cyl.

[Kemp]

Maybe were not saying the same thing. wrist pin to edge of top of 650 pist I found to be higher than 550, crown considerably higher. Will attempt to post pics! 650 piston is on the left and Powroll is on the rt. The powroll and stock 550 pist have the same deck height or wristpin to shoulder height so that they sit the same in cyl. The 650 is much hiher and sits above cyl even at the shoulder. This last pic is the pistons all connected together via wristpins so that their shoulders and crowns can compare. From left to rt we have 550, 650Kaw (modified to fit 650 head by Soos), 650 pist, Powroll pist (590cc). Here are some more pics of 650 pist in 650 barrel on a 550 crankcase, note how much below cyl top it is because 550 barrel is shorter than 650 and 650 rods are longer also.

[mlinder]

Yeah, that's weird, because when we did the same with a 550 and 650 piston, the edge of the shoulder on the 650 piston was a few thou shorter than the 550 piston...

[paulages]

Another (somewhat) clear picture here (http://forums.sohc4.net/index.php?topic=40414.0) of the 650 shoulder being a little taller than the 550. I know lots of folks have done much  more work on this since then, but when I started my project there was absolutely no knowledge on this site of what 550 and 650 stuff would work together.... I'm glad to see how far we've come.

[mlinder]

Weird. I'll take photos tomorrow night of the 650 and 550 pistons we have at Marcuses..

[classic bike tuner]

hallo xedge4lifex

valves can be found here  you need to modify them but the stem is 5,5mm
the are to long and to bigg  [31mm] and after shortening the tip needs to welded with stellite
you can go to 29mm in the standard seat

http://cgi.ebay.nl/RENAULT-CLIO-LAGUNA-MEGANE-K4M-K4J-INLET-VALVES-x8-/140422771966?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b1d974fe

for bigger bore you can use cb 550sc or cb650sc nighthawk pistons [60mm] me4 and me5

and i am new here on sohc4

gerrit

[paulages]

hallo xedge4lifex

valves can be found here  you need to modify them but the stem is 5,5mm
the are to long and to bigg  [31mm] and after shortening the tip needs to welded with stellite
you can go to 29mm in the standard seat

http://cgi.ebay.nl/RENAULT-CLIO-LAGUNA-MEGANE-K4M-K4J-INLET-VALVES-x8-/140422771966?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b1d974fe

for bigger bore you can use cb 550sc or cb650sc nighthawk pistons [60mm] me4 and me5

and i am new here on sohc4

gerrit

Welcome Gerrit! I assume you've used these valves before... if so (judging by your name) your contribution on this site is appreciated. 

[Flying J]

Is there any modification to run the superhawk pistons? obviously boring but anything else? Any idea what the final CC will be or the compression?

[Howell]

hallo xedge4lifex

valves can be found here  you need to modify them but the stem is 5,5mm
the are to long and to bigg  [31mm] and after shortening the tip needs to welded with stellite
you can go to 29mm in the standard seat

http://cgi.ebay.nl/RENAULT-CLIO-LAGUNA-MEGANE-K4M-K4J-INLET-VALVES-x8-/140422771966?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b1d974fe

for bigger bore you can use cb 550sc or cb650sc nighthawk pistons [60mm] me4 and me5

and i am new here on sohc4

gerrit

Welcome Gerrit! I assume you've used these valves before... if so (judging by your name) your contribution on this site is appreciated.  

Welcome Gerrit,

Certainly yes Gerrit has used those valves before.
He's the tuner of our engine and the mechanic for many other CB SOHC riders in Holland.
These valve's are fit in our engine.
Gerrit is the man with the golden hands.

See the picture:  G.L.Classic Bike Tuning

[kos]

Anyone looking for pistons for 500/550 Honda SOHC fours, I have some now that you might be interested in.
Designed for race use, compression ratio 61mm 11.5/1   2 compression rings with three piece oil control ring, forged JE Pistons weigh less than 142 grams. PM me if interested.


KOS

Mark@m3racing.com

[Flying J]

Those look nice but im going to guess they are well out of my price range.

[classic bike tuner]

Is there any modification to run the superhawk pistons? obviously boring but anything else? Any idea what the final CC will be or the compression?

60x60x50.6x0.785x4=571,9824 cc
compression is slightly higher as stock 
with the stock cam no modification but take care with piston valve clearance

[xedge4lifex]

Maybe were not saying the same thing. wrist pin to edge of top of 650 pist I found to be higher than 550, crown considerably higher. Will attempt to post pics! 650 piston is on the left and Powroll is on the rt. The powroll and stock 550 pist have the same deck height or wristpin to shoulder height so that they sit the same in cyl. The 650 is much hiher and sits above cyl even at the shoulder. This last pic is the pistons all connected together via wristpins so that their shoulders and crowns can compare. From left to rt we have 550, 650Kaw (modified to fit 650 head by Soos), 650 pist, Powroll pist (590cc). Here are some more pics of 650 pist in 650 barrel on a 550 crankcase, note how much below cyl top it is because 550 barrel is shorter than 650 and 650 rods are longer also.

awesome post, this is also something i had been wondering about for a while now. 550 crankcase with the gsxr or 650 connecting rods and 650 pistons with the 650 head, think that would give you a couple more mm? the 650 pistons, head and cam would be an awesome hop up while utilizing the stock 550 bottom. especially keeping the kicker. great post

hallo xedge4lifex

valves can be found here  you need to modify them but the stem is 5,5mm
the are to long and to bigg  [31mm] and after shortening the tip needs to welded with stellite
you can go to 29mm in the standard seat

http://cgi.ebay.nl/RENAULT-CLIO-LAGUNA-MEGANE-K4M-K4J-INLET-VALVES-x8-/140422771966?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b1d974fe

for bigger bore you can use cb 550sc or cb650sc nighthawk pistons [60mm] me4 and me5

and i am new here on sohc4

gerrit

YESSSSS i have two spare heads i can toy around with, and ill definitely end up getting these valves, and try to get everything cut in. thanks so much