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Cam Shafts


mbelik

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  • 2 years later...
Will it be ok not to change the springs, as I cant compress them down with the engine still on the bike. :confused24:

 

Quote from Skydoc_17 when he was advicing me when I was having this mod done on my 1998 Tour Classic / same motor as yours :

 

Here's the scoop on the differences in the parts between your bike and the VMAX and the MKII VR:

Your bike's REV Limiter shuts your bike off at 6500 RPMS.

The VMAX's RED LINE is 9000 RPMS but it reaches MAX TORQUE at 7500 RPMS.

The MKII VR's RED LINE is 8000 RPMS.

My thinking is if we can get your motor to REV to 8000 RPMS without valve float you will be into those VMAX Cams for full torque, any higher RPMS than that is just noise and engine wear.

Your bike uses a single spring on the valves and there is NO WAY you will be able to use ANY of the springs, spring seats, keepers, or spring retainers. (the metal is too soft and won't handle the higher RPMS)

Here is a list of the parts that will need to be replaced if you want to run double springs on your stock valves for the VMAX Cams.

 

3 SEAT,VALVE SPRING

26H-12116-00-00 16 pc. SPRING,VALVE INNER

36Y-12113-00-00 16 pc. SPRING,VALVE OUTER

36Y-12114-00-00 16 pc. SEAL,VALVE STEM

51Y-12119-00-00 16 pc. RETAINER,VALVE SPR

30X-12117-00-00 16 pc. COTTER,VALVE

30X-12118-00-00 32 pc. LOCK, VALVE SPRING RETAINER

"Quote ended""

 

There are some people in the club that have had this done or done it themselves and I am one of them that had this done. Have not had the chance to ride the bike myself after this was finalised since I live in Iceland and keep the bike in USA. But my friend Big Tom in Alden NY keeps my bike and rides it around from time to time and he says that he wakes up every morning with this big grin on his face that he just can´t get rid off. Has had it ever since he took the first ride. But the gas milage is pretty scary he says. He takes it on the interstate for work and has not used the fourth gear till now even though the bike has the V-Max rear.

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Can't wait to get this finished should feel like a new bike.

 

Ok so I have the dynatek in and the carby. I have already purchased the springs with all the other bits but having a really hard time getting them in. Are there any tricks with getting them on without taking the engine out or the heads off, that's if I can get the heads off without taking the engine out?

 

Any ideas?

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You can try using an old sparkplug and gut it down to just the base and tap it with a 1/8 pipe tap and attach a hose fitting to it. Next screw the converted plug into the cylinder your working on and connect up the compressor now don't turn on the compressor just yet. Make sure all valves are seated and then turn on the compressor and fill the cylinder with air leaving the compressor connected will hold the valves in the closed position while you swap the springs.

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I guess the pistons are in the upper position so the valves can't fall through. I think I going take the cylinder heads of anyway. I have ordered some head gaskets I just hope that I can do it with the engine in the frame.

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This process is almost as old as cars themselves. When the valves are closed the cylinder holds pressure aka cylinder compression when you remove the springs the internal pressure holds the valves closed.

 

Check out these sites for more info

 

http://www.chevelles.com/forums/showthread.php?t=154278

 

http://voices.yahoo.com/how-change-valve-springs-7013038.html

 

http://forums.corvetteforum.com/c5-tech/3068434-changing-valve-springs-what-psi-to-set-air-compressor-at.html

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Yea no coolant changing or on the floor, no oil changing needed if done recently, cost saving (no need for new gaskets) time saving the list goes on.... Just make sure you follow the sites recommendations of cylinder pressure and use a regulator if you don't have one Harbor Freight has them. One other thing I would also recommend is loosen the oil fill to help bleed off the blow by

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"80-90 PSI inside the chamber hold the valve up. The only problem is that the air compressor has to maintain at least 30-40 PSI to hold the valve up the entire time you are changing each spring. Any less, and you will be removing the heads to retrieve the valve."

 

Now as a side note and also as a just in case I would bring each cylinder to TDC or close to it. If for any reason you loose the pressure the valve will fall into the cylinder with the piston at or near TDC the valve stem will still be sticking out of the head so you can grab it. If you have a compression gauge connect it and turn the engine over it will show you what the cylinder pressure is just stay 10 - 20lbs below that. If you don't have a compression gauge Harbor Fright has them cheep or check any auto supply shop.

 

http://voices.yahoo.com/how-change-valve-springs-7013038.html

3rd paragraph down ....

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You have to be vary careful using air pressure because if the piston goes off top dead venter, the air pressure will slam it down, turning the crank.

The last time I did this was on a small block Chevy engine. I took the spark plug out and fed a soft rope in on top of the piston. I then cranked the piston up until the rope pushed on the valves. To me, this much safer and cheaper. Just make sure you leave some rope hanging out.

RandyA

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Ok so I got one of the heads off and now I'm waiting for the parts to put it together. Wasn't that hard after all. Not sure if I should bother cleaning the carbon off the pistons?[ATTACH]79176[/ATTACH][ATTACH]79177[/ATTACH][ATTACH]79178[/ATTACH]

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