Topic: Vanguard 20HP V-Twin Questions

[Tom Fox]

Just picked up a Vanguard 20hp V-Twin and have a few questions!

Did a few searches , got some answers, some helped some need clarification....

What NEEDS to be done to this engine prior to using it as a race engine?

I've read that the valve springs should be replaced with EC ones.

How are the B&S oil filters? Or should another brand be used?

What kind of oil pressure readings should I expect?

Will the factory fuel pump be adequate?

What about the carb?

Aftermarket air filter adapter avail?

I will have to remove the governor internals correct?

Whats a recommended oil viscosity to use?

I do plan on purchasing a ARC flywheel, new valve springs, considering roller rockers and a camshaft...

Is it worth running this engine with the stock cam? I'm trying not to spend  to much ......I like being married!

[mowcephus]

Best advice I know is Send it on down to George.  He's got access to all the goodies to make this engine run up front if you can drive it.

[Squidd]

You put up a "basic" list there...I wouldn't go much cheaper than that...

You can always add balancing the crank to the ARC rods and oversized pistons that go into the sleaves that are pressed in after you bore it out....

And then the oversized valves and seats and start looking at titaniunm parts...Full bearings in pan (more machine work on your crank) and get the cam bearings as well...

[Squidd]

And don't forget the high torque starter...!!!

[Tom Fox]

This is dangerous having an engine that has so many opportunities to modify!!!

I got to "SLOW DOWN" a little on my spending....I want to put a couple IMOWS togethers for my kids, Would love to put a CP together....and the list goes on!!!

I don't mind not being one of the top runners this year, I want to get some seat time in more than anything.

I'm just asking about some BASICS that I can do to this engine to make it somewhat of a race engine.

I'm thinking of spending around $800.00 on modifications for now...so looking for $800.00 worth of advice! Thanks!

[Squidd]

There are a dozen ways to spend $800 two or three times over, but I know what your saying...

There may be varying opinions on this, and end cash flow depends on the actual /usable shape of the motor "as is" and what requires replacement machine work and what can just be "freshened up"..

I'd concentrate the cash on valve train, springs, retainers, valve job, cam and carb...

Gotta breath...

But you gotta have compression and be able to suck air/fuel in and out too... so I'm counting on piston, rod, and cylinder being in "decent" shape, honing, porting and new rings...

All this stuff needs to be lubed to stay together modded or not so some work on the oiling system is in order, generally opening ports, cleaning, seals and crank breathing...

That'll suck your $800 up pretty quick depending on how much you do yourself and how much is sent out or "has" to be replaced...

Next piece after the above would be a Billet wheel...

And then (after you win the lottery) the secondary list I gave you above....

[Tom Fox]

Maybe I'll go back to my original plan of the opposed twin engine! Can't spent to much on stuff that is not avail!!!!!

[Squidd]

Actually..the list above applies just as much to a flatty twin as that OHV....

[Mowindown]

I would suggest sending the heads and carb to George Herrin and let him work his magic (his work is amazing).  Then get a good cam.  While you are in there get a set of ARC rods. That will get you a good start.

[George Herrin]

Dude I am a Vanny guru. Want to go fast you can. Bullet proof and fast will run app. 1200 in parts. Bottom line you skimp in one spot you pay the price elsehwere. Remember the old commercial pay now or pay later, well this applies to the vanny.

Will start inside the motor.
Cam 125.00 to 270.00 depending on who you buy from. I highly recomend Precision or me and its precision.
Longer than stock Rods 229.00 ARC or 225.00 E.C.
Using the longer rods you cut the stock pistons creating flat tops and more compression. 30.00 new rings E.C. 29.00 a set.
Now outside several options. 16hp heads again smaller chamber and more compression new unported E.C. 150.00 ea. ported and all the works, springs and retainers 300.00 ea. Used I have several sets stock 75.00 ea. ported and all my magic touch including dual springs and billet retainers 200.00 each
Billet flywheel 345.00 E.C.
High torque Starter 160 E.C.
two steel push rods to replace aluminum E.C. 4.50 ea.
have that carb built to the hilt to run that beast could run as high as 700.00 depending on level of build.
K&N Airfilter E.C. 42.95
Air filter adapter 39.95
Roller rockers Performance V-twin 325.00 Thats all I would recomend you buy there.
K&N filter for crank case breather 12.95
Gasket set to include very thin aluminum gaskets (more compression) E.C. 48.00

Now if you do all this and don't need to bore and sleeve unless its wore out, if you can drive and ain't skeered you will have a rocket ship.

[DanW]

How about saving a few bucks on that carb work and going with something from a motorcycle... say a 450 or maybe a 250 2 stroke?  Would something like this necessarily cause you to pay later?

[Tom Fox]

Dude I am a Vanny guru. Want to go fast you can. Bullet proof and fast will run app. 1200 in parts. Bottom line you skimp in one spot you pay the price elsehwere. Remember the old commercial pay now or pay later, well this applies to the vanny.

Will start inside the motor.
Cam 125.00 to 270.00 depending on who you buy from. I highly recomend Precision or me and its precision.
Longer than stock Rods 229.00 ARC or 225.00 E.C.
Using the longer rods you cut the stock pistons creating flat tops and more compression. 30.00 new rings E.C. 29.00 a set.
Now outside several options. 16hp heads again smaller chamber and more compression new unported E.C. 150.00 ea. ported and all the works, springs and retainers 300.00 ea. Used I have several sets stock 75.00 ea. ported and all my magic touch including dual springs and billet retainers 200.00 each
Billet flywheel 345.00 E.C.
High torque Starter 160 E.C.
two steel push rods to replace aluminum E.C. 4.50 ea.
have that carb built to the hilt to run that beast could run as high as 700.00 depending on level of build.
K&N Airfilter E.C. 42.95
Air filter adapter 39.95
Roller rockers Performance V-twin 325.00 Thats all I would recomend you buy there.
K&N filter for crank case breather 12.95
Gasket set to include very thin aluminum gaskets (more compression) E.C. 48.00

Now if you do all this and don't need to bore and sleeve unless its wore out, if you can drive and ain't skeered you will have a rocket ship.

I just added all the options up that you have suggested........$2998 for parts only!

I wish we could put a small block Chevy in our mowers...I can get a brand new GM PERFORMACE 350/350 HP for the same price!

Some mods will have to be done...but there is no way I can swing that kind of money all at once

[George Herrin]

What I priced you was the best of the best and with options, and if

Some prices have varying expense you don't need the 700 carb. Do alot of the head work yourself, I.E. port and springs. Save moeny there, We all know speed costs.
Buy essentials
Rods
cam
cut pistons
stock heads used 16 hp heads with your port work just buy springs
billet wheel
K&N filter and adapter for carb and breather
gasket set to include the thin head gaskets
roller rockers
and two steel push rods
Oh almost forgot Walmart oil filter 4967 $2.97
 Or pick from the list what you can afford.
It can get expensive speed always does, how fast and reliable you wanno go depends on how deep your pockets are, Thats ture with any type of racing regardless.

[Tom Fox]

What kind of compression readings will i get with this engine? Thought I'd check that before yanking it apart!

[matt25001149]

im guessing its an 8:1 motor but i know thats not what your lookig for


on another note my kohler vtwin is a 8.5:1 motor and i have 160psi on both sides