mines5

Hi, i have heard alot of good things about jun 264 cams and i am about to buy them but i have a query regarding them.
On JUN's website and else where i have seen that it is recommend running upgraded valve springs with JUN 264 cams for 4g63 engine as their lift is 10.5mm and the stock springs can handle total of 11mm lift. Compared to HKS 272 which has 10.8mm lift do not require valve spring upgrade and people haven't complained about valve float problem. What is the reason behind this ? i want to install JUNs without changing stock valve springs.

If anyone has used JUN 264s , what is the response ? i intend to use them with stock turbo however i might change to a different turbo.

Thanks.

kpr

iTrader: (6)

these cams are almost antique now, what used to be consider high lift no longer is, thats why Jun says needs springs, these were designed 10+ years ago. Even HKS was updated cams, the 272 are discountinued.

Bottom line, get GSC s1 and make more power

94AWDcoupe

iTrader: (125)

jun cams rocked compared to HKS cams. they were much more aggressive that HKS 272. the jun 264 did not get much recognition on these forums. but the jun 272 is still an awesome cam after all these years. I have used the jun 264 on the early 4g63 and it was an awesome cam. a mild spring upgrade is all that is needed. I would bet gsc1 are mild compared to the jun 264 and will not make more power.

Faisalm

I love that JUN272... One of the best cams I've installed.

Back to the JUN 264, I would go another route if you're not going to upgrade springs and retainers, something like a GSC S1, although it won't make as much power as a JUN 264 probably, it will meet your requirements of no spring upgrade.

If you do get a spring upgrade then don't even think of the JUN 264...

mines5

I am just worried about the valve float scenario, currently i am on a strict budget .. I want to upgrade to JUN 264s but without after market springs.

Did you hear from any one that he used JUN cams with stock springs and dropped a valve ?

mines5

The whole point is why do they require a valve spring upgrade? they are lesser in lift compared to hks 272 , their duration is also less but still upgraded springs?

mines5

Why opt for GSC S1 they also idle harsh but dont require spring upgrade. i am getting JUN cams in 1/3 of the price of GSC S1 but i want to make sure that while saving some money i dont get into a deeper problem.

Faisalm

Are you going to be reving past 8000 RPM? If not, that lift shouldn't cause any issues with stock RPM limit, so you're good to go...

English Racing installed a GSC S2 cams I believe it was on stock springs and retainers and didn't have any valve float issues, but they recommended not to go beyond 8300 RPM on stock springs.

evo8426

iTrader: (27)

Instead of rushing to buy cams and install them, save up the extra $250-300 needed for springs and valve spring tool. Rushing on a part this expensive you do not want to do it twice because of being impatient.

94AWDcoupe

iTrader: (125)

lift and duration specs says nothing about "ramp rate" . it is the ramp rate that determines if you need a spring upgrade. a good cam will snap the valve open quickly and hold it open longer and return it quickly. stock springs loose control on the fast ramps.

you might get by on stock springs if you keep the rpm down. 7000-7500

mines5

I will definitely not go beyond 7000 rpm as stock turbo's efficiency starts to decline after 5500 rpm. Although i have 10.5t hotside but still illdecrease the limit to 7000 or may be 200 rpm less. Depending upon the loads and response i am getting.

mines5

So what u mean is that HKS 272's ramp rate is lesser than JUN 264s even though its duration is larger..

mines5

You are right .

mines5

Is there any difference in USDM and JDM evo 8 cams and cylinder heads?

EvoX320GSR

You should wait for discount season too! Black Friday, maybe a 4 th of July blowout...