[geoffw]

sho,

Typically I would agree with you, but there is an ENORMOUS amount of mis-information in your post that I have to disagree with. It appears like you are spitting out information you've read on a message board and not facts that youve learned from lengthy R&D and personal experience.

I can tell you that Ive spent nearly 20hrs a week since September, R&Ding these 420s and have gone from a stock 420 to a completely built 440 and pretty much every combination in-between. All of my testing has been done on the same white 1992 Club Car DS with 12" rims and 18" low pro tires, utilizing the same CPP clutches that I started out with. So I can assure you that my R&D was completely relevant to the subject.

Furthermore, I have had direct contact with Charles Mosley (minidragbike), Jeremy Parsons (Parsons Racing Engines), Russell @ NR-Racing, Shane @ Affordable Go Karts, and Tim Iskenderian (Small Engine Cams). These people are some of, in not THE, TOP Clone Engine builders in the country. Each and every one of them has led me in the right direction and they have all contributed to my 440 program in one way or another.

My goal was to develop an engine specific to Golf Carts, that was extremely affordable, yet also yielded massive power gains and maintained reliability and low end torque. The goal was to develop this platform and make it available for HALF the cost of a typical v-twin big block swap.

As of right now, I have 440 engines 2 weeks away, and performance parts 2 months away. I have used Parsons and Isky parts exclusively in the meantime to test the 420 & 440 CLONE engines that I have in house. These are the FACTS:

-Big Engines Like Big Cams , The bigger the cam I put in them, the more OVERALL HP and Torque they gained. I tested 7 cams, starting with a 220 Duration/.280 Lift cam. I ended up with a 260 Duration / .410 Lift cam that Isky ground custom for me. Every time that I went up to a larger cam, I gained more power throughout the ENTIRE rpm range. Iam positive that I could go even larger, however, I feel that the 260/410 cam is a great all-around setup and will serve as a dual-purpose cam so even the kart and lawnmower guys can use it. Eventually I will test some .500 lift cams, the real issue I ran into was clearance with the crank. This cam is .020" away from hitting as it is.

-7000rpm is the limit for the big blocks when it comes to reliability(they dont like to rev), thats the reason I stuck with stock size valves. The stock 35/31mm valves wont make power past 6500rpm anyway, the key to keeping these engines alive is keeping the RPMs down. Keep it at 7k or under and you will not have a reliability issue.

-Stock Clutches are good for stock engines, if you want to make power and use it, you will need to upgrade the clutch first. Stick with CPPs Clutch, its rated to 30hp. Im probably making 32-33 and its holding up just fine. You dont see V-Twin swaps with stock clutches very often! More Power = More Supporting Mods...Bottom Line

-A Built Clone with a Billet Rod, Hard-Face-Welded Camshaft, Stainless Valves, Chrome Silicon Springs, Aluminum or Titanium Retainers. Chromoly Pushrods, and Shaft Rockers, is going to be MUCH stronger and more reliable than stock. The stock rod flexes and deforms under high power, it also is a piss poor design for high speed lubrication and will gall the crank. I ran a stock rod and valves for ALONG time and ALOT of abuse. I didnt have 1 problem until the day I put a cam in it. Even the small cam was such a drastic power increase, the stock rod and valves ate the sheets within 4 hours. Stock valves are junk and cannot withstand the higher valvespring pressures of dual springs, so bottom line is, they dont call it a "Built" engine for their health. Its "Built" so it can RELIABLY take the abuse associated with a high horsepower application. Both ARC and Parsons rods have taken tons of abuse on the go kart tracks which are significantly harder on any engine than a Golf Cart is. 6500+ rpm for 30 mins at a time.

-Dyno numbers mean nothing! I have a drag mustang that makes over 1200HP but it only makes 700rwhp on a chassis dyno. There are too many variables to consider with dynos, so its really a waste of time trying to compare them in any way, especially when considering two different setups. I tune clone'd golf carts based on feel, its not like we are drag racing and trying to get every last .01 of a second. All we care about is that the cart starts easily, idles smoothly, and pulls smoothly through the whole rpm band without issue, and of course...it must pull really hard, and do big wheelies :)

I would continue but Im very hungry at the moment and dinner is ready. I hope to post some good videos this weekend but I just havent had time lately. Im anxious to get the built engine'd cart on youtube. Its way past the point of being safe and is really cool seeing as how you can get soo much power into a stock height cart, no lift kit needed(HUGE advantage of clones over v-twins.).

-Geoff Warner
702-335-4002