540 LC Motor SN & HP Ratings

[racerrob6m]

I will be looking at a 81 SRX 440 that has a 540 Vmax motor in it next week.
My questions are as follows & hopefully none of them are considered too dumb:

A) Is there a place-listing to find out what year the motor is based on its sn?
I will be looking at the motor sn to determine its vintage.

B) What were the HP ratings on the 540 LC ??

C) What years were the most dependable?

The seller claims this sled-motor combo was once used in drag racing & was at one point a "610 cc" set up but has been returned to "stock" jugs & pistons.
Was there a "big bore" option out there?

What is the track length on these "oldies"? Were they a 121 or the 116 as on the early Phazers?

And what was the dry wieght rating for these old girls.

Thanks for input & this is a real cool site.

Rob

[tyler440]

A) Is there a place-listing to find out what year the motor is based on its sn?
I will be looking at the motor sn to determine its vintage. Best place is here hahaha it all goes by the first 3 digits of the vin... http://www.vintagevmax.com/serial_numbers.htm or http://www.vintagevmax.com/images/sled- ... efixes.jpg
B) What were the HP ratings on the 540 LC ?? around 86

C) What years were the most dependable? 84+ had the carbs all straighten out but the actual hardware is the all same

The seller claims this sled-motor combo was once used in drag racing & was at one point a "610 cc" set up but has been returned to "stock" jugs & pistons.
Was there a "big bore" option out there? yeah aftermarket companies had big bore kits... they are really in the shadows still tho (ive been watching out for info but not finding much)

What is the track length on these "oldies"? Were they a 121 or the 116 as on the early Phazers? 121 on all vmaxs 81 srx was also 121 but had a slightly different skid, most were retro fitted with the vmax skid it seems

And what was the dry wieght rating for these old girls. 472lbs not sure if that is dry or wet but i assume dry http://www.vintagevmax.com/images/highr ... uarter.jpg they feel feather light tho... especially after you ride something else

[tyler440]

oh and welcome to the site... surf around her for a few hours and you'll find all kinds of awesome info

[racerrob6m]

Hey tyler440:
Thanks for the answers & links. This gives me some food for thought for sure!!

I had the seller give me the sn on the 540 motor & it is a 83 motor. So, I see a number of posts here that the more "solid motors" were 84 & up??

I will be looking at this ole girl later this coming week.
What size were the oem carbs??
He says that the ones that are on this one are 44mm Mikunis.

So, can the 83 540 be a solid reliable motor or is it a "time bomb" waiting to go off??

Thanks again, Rob

[tyler440]

no the 83's are fine motors... the only things that changed from 83 to 84 were the oil injection ratio and the jetting.... if your oil pump has any red paint on it then that has been updated...

stock carbs were 38mm mikunis... a lot of guys put bigger carbs on them thinking that would make more hp but it wont (at least not without significant motor work)

[chrisrider63]

Tyler is right, the 38 carbs are the way to go, in the update porting articles it states that using bigger carbs will not make a difference. Set it up stock and it will be plenty fast, i suggest buying a service manual for the 540.