Vmax engine for my 1985

[pegscraper]

Thanks again for that site, Squeeze. What a pile of information. I ended up having to register after all so I could see pictures. There were too many of them I wanted to look at. True to form, I've already turned up a modification I didn't know about that I will now have to do this winter - R1 coil on plugs. I have never been nuts about how long the plug wires on this bike are, especially the rear ones, but didn't think there was anything that could be done about it. And while the front coils are nicely protected from weather up under the tank, the rear coils are in a pretty lousy location, down where they get road grime and water thrown on them. But I couldn't see room to mount them anywhere else. Now there's a nice solution. Big sigh. It never ends.

[Squeeze]

Thanks again for that site, Squeeze. What a pile of information. I ended up having to register after all so I could see pictures. There were too many of them I wanted to look at. True to form, I've already turned up a modification I didn't know about that I will now have to do this winter - R1 coil on plugs. I have never been nuts about how long the plug wires on this bike are, especially the rear ones, but didn't think there was anything that could be done about it. And while the front coils are nicely protected from weather up under the tank, the rear coils are in a pretty lousy location, down where they get road grime and water thrown on them. But I couldn't see room to mount them anywhere else. Now there's a nice solution. Big sigh. It never ends.

 

Room under the Tank .....

 

well, i smell a 'Rat' there :crackup:

 

Seriously, i'm happy if you're happy. Coil on Plug is not a new Invention, Ford had it, several Bike had it since Years. But i agree, with your desperate Seek for Room this might be the Way to go. But don't expect too much out of that Mod. The Spark will be somewhat crispier, and this helps burning down the Fuel more efficient, but Wonders are very seldom nowadays.

[pegscraper]

Yes, they've been around a while on some vehicles. On this bike, there's no room under the tank for the stock coils except way up front. They'd be even farther away than they are now. The jury seems to still be out on the advantages, probably because it's winter and no one is riding much. Some are claiming quicker starting, smoother running, slightly better mileage in the highway. They're also very inexpensive. I just don't like the location of the stock rear coils. They get wet and beat up by road grime. I've had problems with mine after extended rides in the rain. And the plug wires are not serviceable. The whole coil would have to be changed. COPs have no plug wires. Whatever the reason, the VMX boys seem real happy with them.

Edited December 19, 2008 by pegscraper

[GaryZ]

Thanks. I had already seen that one. I've been looking for one that could at least be perused through without having to register.

 

The easiest ways for more power on a 1st gen are going to be VMX cams and a V boost system. You could also get the 35mm VMX carbs, where the Venture has 34mm carbs. You may or may not feel much difference there though.

 

Reviewing the specs I found that the Vmax also has 1mm larger valves. The smaller VR valves are probably better for the VR when using Vmax cams . . . Higher intake velocity at lower rpm. I am concerned that the Vmax cams and V-Boost will hurt the low-end torque needed to move my 750lb VR with my 260lb butt and my 138lb passenger. Anyone have this set-up and can comment? I would rather not hear speculation.

[Squeeze]

Reviewing the specs I found that the Vmax also has 1mm larger valves. The smaller VR valves are probably better for the VR when using Vmax cams . . . Higher intake velocity at lower rpm. I am concerned that the Vmax cams and V-Boost will hurt the low-end torque needed to move my 750lb VR with my 260lb butt and my 138lb passenger. Anyone have this set-up and can comment? I would rather not hear speculation.

 

Maybe this Write-up may answer some of your Questions ?

 

It's not mine, i just made it up for further Reference.

 

The V-Boost Setup won't hurt the low End Torque because it's not operating at low RpM. The Vmax Cams are a tad sharper, but riding both Bikes, i'm sure such a Setup won't dissapoint you.

Edited February 26, 2009 by Squeeze

[GaryZ]

Thanks for the pdf. I had read that a while ago and missed the last statement. He believes the torque curve will move 2000 rpm up from stock. I guess the question remains . . . How much torque is left for normal riding?

[Squeeze]

Thanks for the pdf. I had read that a while ago and missed the last statement. He believes the torque curve will move 2000 rpm up from stock. I guess the question remains . . . How much torque is left for normal riding?

 

Enough

 

 

 

Of Course the sharper Cams might have a somewhat negative Effect on the low End Torque. But this sure won't hurt the rideability. With a sharper Engine you shouldn't ride around heavy loaded and asking full Power at 2k RpM anyway. This is bad for the Crank Bearings and asking for much more Stress is a Killer for them. You gotta keep in Mind, a V4 Motor, even with a Balance Shaft never will be absolutely balanced. If you lug the Engine and accelerate at WOT from 2k RpM, you put very heavy Stress on the Main Bearings at a relative slow rotational Speed. This ist like a small Hammer beating on it constantly. If you ask WOT at 3200 RpM, the Crank is much more rotational SPeed and the Stress on the Bearings is reduced by a good Amount.

[GaryZ]

Thank you for your speculation, I do appreciate all input.

 

Any one out there that has made this conversion want to share?

[pegscraper]

I do have VMX cams and adapted a V boost system to fit my bike. No speculation here. So what if the valves are 1mm smaller. They can still use all the lift they can get. More breathing efficiency is always good. The VMX cams are just not that big anyway lift-wise or, duration-wise either. They're about the same size as what was in the XS1100s and what is in the FJR today. Do those bikes lack any low end torque? The Venture cams are borderline too small. I run the V boost valves manually with a choke lever from a V Star 1100. If I want, I can have it wide open at idle speed and all the way up. I can tell you this set up has no trouble hauling around this 800 lb. bike with two passengers who weigh a good bit more combined than you two do (and that's all I will say about that). Does the guy in that pdf have any real proof that the powerband will move up 2000 rpms, or is THAT speculation? There's nothing to be afraid of here. But in the end - you're of course welcome to do what you like.

[GaryZ]

Dear Pegs,

Thank you for your input on the Vmax cams/V-boost installed in a Venture engine. Your tone suggests that I have in some way hurt your feelings. I assure you that was not my intent.

[GaryZ]

I found Vmax cams on ebay and they should be on the way. My plan is to install them in a 1987 VR 1300 engine with 41,000 miles on it, and stuff it in my 1985 VR.

 

I will let ya'll know how it works . . .

 

Thanks for all the info!