predator 670 vs vc460

[curdog71]

Originally Posted by raydhd

I have the VC 460 with the stock cam and rod with the 1.3 rockers.I have run about 12 hours with a red line of 5000 rpms.Are you over revving it? with stock tires I was at red line in less than 30ft.With 20 inchers slightly more.Now with the 24s I was going scary fast at 4000 rpms.

I have 22 inch tires and it will rev to 5500, I was told by Geoff that this engine is good to 6000... i dont run it hard very often but do like the quick burst every now and again, just dont know yet what is causing it to break the valve springs yet.... havent heard back from Geoff yet...

[slonomo]

With your setup you should be using the double springs, is that what you have?

[curdog71]

no dont have the double springs, VC built the engine and I did ask if thats what I needed and I was told no...

[Field6565]

Originally Posted by curdog71

no dont have the double springs, VC built the engine and I did ask if thats what I needed and I was told no...

If you broke the valve springs twice I definitely recommend using the double.

[curdog71]

I agree with you but i was told I didn't need them... VC told me I was the only one having this problem and they haven't told me why they were breaking... they did say that they went to a better spring then what was previously used...

[curdog71]

I haven't installed the new engine yet, it will be here today, kinda scared to run it since I've had so much trouble out of it...may just scrap that idea and buy me a different engine like the vanguard. Not sure what to do, im kinda in a bad situation because they said I don't have any warranty on this new engine because it is a complete replacement..

[jeff70]

Originally Posted by curdog71

I haven't installed the new engine yet, it will be here today, kinda scared to run it since I've had so much trouble out of it...may just scrap that idea and buy me a different engine like the vanguard. Not sure what to do, im kinda in a bad situation because they said I don't have any warranty on this new engine because it is a complete replacement..

Not to diss anyone, but if they won't offer any warranty on a complete replacement I would sell it and look elsewhere. I have had a few companies I used to work with that had this policy, Notice I said used to work with.

[curdog71]

I totally agree with you jeff70, Vegas Carts have just completely blew me off after I started having major problems, I know they are a site sponser and so forth, I ordered my engine and complete installation kit from them at a cost of 1400.00 dollars, never complained about the price I just saved up and paid it when I got the money, made my order on jan 26 and got my installation kit and engine in a timely manner, but not the 780 drive clutch it was on back order for two weeks...I get everything installed and i'm waiting for the clutch while my warranty is ticking away, had a few MINOR issues with the engine and VC was quick and speedy about sending me what I needed...keep reading... one small issue was the soft cheap aluminum starter/gen pulley that I received with the installation kit, it did not last long and cracked, they were very helpful at getting me a new one, and when I received the new one it I realized they had upgraded to a better quality one... next minor issue was my fault because I jetted the main jet too big and wasn't sure were or what to buy so I called and asked to buy one and they volunteered to send me one no questions asked, OK...this is were the trouble begins, I finally get this thing running right were i can break it in nice and easy, after about 20 or so hours of babying this engine around I can see what it has got.. well after a few runs over 5000 rpm and many checks of valve lash it breaks a valve spring in half, and drops exhaust valve on the piston, valve is bent and the piston survives with only a scratch, so I call VC and they kindly send out a new replacement head, at this point I was really happy with their service department, just not happy with the engine being down and my warranty ticking away again...well after a week or so I get this thing back together and get a few days out of it and the same thing happens again, valve spring breaks drops valve and dents piston this time...VC is concerned at why this is happening and tells me this is very very rare thing to happen, I send entire engine back for a replacement one, more down time, lots of work and warranty is still ticking away.... I call and check to see when they can get the new one out and they tell me they are waiting on new style valve springs from comp cam, I'm thinking good deal better springs may hold up longer, well 3 weeks later my engine comes in, which was today....I was told I have no warranty on this new engine because it is a complete replacement engine, even though my original warranty still has a few days left, I don't have the 1.3.1 rockers on my new engine, I have the stock rockers now and I had 1.3.1 on my original engine....I have sent several emails to VC since friday to find out what they think the problem was with the springs breaking since I was told I was the only one having this problem, just being cautious with this new engine since it doesn't have ANY warranty and making sure it wasn't something that I did and don't want it to happen again, because i'm really tired of the breakdowns and all the work that I have put into this...... no response from them at all...I did call today and talk to a sales person not a tech and he told me they cant get the 1.3.1 rockers anymore, I ask him why I was the only one having this problem and he said I just got some bad springs, hmmmmm....twice in a row bad springs and as many engines they sale Im the only one having this problem? I just feel that Ive been blew off because of the problems ive had with the engine, I did get it installed today, started and idled it for a few minutes, just wondering if anybody else has had problems with their valve springs?
any advice will be appreciated thank you.....

[sho305]

I have his 1.3 rockers on a stock cam 420 and no issues yet. Another guy did have problems got it fixed and sold the cart, I think that was before he had 460 engines. I don't know, you could always buy springs from NR racing or similar Kart place. 1.3 rockers will certainly be harder on the springs. I wonder about mine it seems to not be pulling the top speed but since I am messing with clutch tuning I can't say its not my clutching. It still pulls hard at normal rpm. I would guess you have nothing to worry about with stock rockers.

I would tell people to break them in for a while, like 10gal gas minimum. It took a long time to break my 420 in, I could feel it loosen up and run better. People that stick a rod do it by high rpm before its broken in, usually. I kept it under 4K for some time, didn't put the 1.3 rockers in until the next summer.

[slonomo]

I have the same setup as you and have never broken a spring. Just sayin.