just a small debate over what valve springs can be used with jun type 3 cams. a guy i know had these cams for about 2 years in a stock b16 head with itr outer valve springs, portflow inner valve springs and skunk2 retainers. he can take the motor to about 9200rpm with no problems. another guy i know has the same cams and setup in an itr head. when he took the car to about 9000rpm the cam snapped on him! i called jun to see what they had to say about it and they told me to use their valvetrain and only their valvetrain. then i called tom at portflow and he said that itr outers, portflow inners and skunk2 retainers were perfect for jun 3's. who should i believe? any help will be appreciated. thanks!

 

Do a search in the ITR forum. There's tons of info on this in the archives.

 

JUN valvetrain only!!! I would definately not reccommend anything but.

 

believe the manufacturer.

 

 

Yup, Portflow inners shattered my friend's JUN3 intake cam, that CRVTEC went byebye..... It destroyed the pistons, cracked the sleeves, and fucked the head

 

There's a reason why Jun says to use their parts with their cams.

 

especially because portflow valve springs are too stiff... thats what caused a lot of the old Jun3's to shatter. the cams have been re-engineered now so they should be fine with the Jun valvetrain especially because they have progressive spring rates just ask advanracing62.... hes the jun guy....

 

JUN springs = linear progressive.... Portflow inners = NOT... They are cool for OE cams tho... Laterz

 

Get jun springs

 

haha thanks!!! Yeah there's a thread on here https://honda-tech.com/zerothread?id=190828 That tells about JUN's customer service, also notes what springs were used and what happened. There is a first part to the thread (don't have time to look it up now) I was like you at a Point, wanted to get portflows cause they were a little less spendy. Then I got to thinking about it and said "What's more expensive, a motor or valve springs?" I'm sure you know which I chose. HTH

 

will jun3's accept crower "dual valve springs - Eibach edition" with titanium retainers... or they won't... do the Eibach have to much seat pressure or they are not progresive or too stiff.... any imput would be appreciated!!

 

Drop-in installation, no machine work required. Works with stock valves and keepers..... I'm still going to say JUN ONLY!!! If you're going to run coward... I mean crower then use their springs... SK2 use SK2 springs, Toda use Toda springs.. and so on.

 

I have stage 3 cams.... I wanted to test jun'3 but withut having to pull my whole valve train out.. kinda to do back to back dyno testing.. on the same engine and port job.. but was mostly curious to see if the crower springs would handle the lift and duration of the JUN cams... we all know JUN rules but we can't all afford your pocket book

 

A good practice to follow is use the cam manufacturer's springs. Personally, I don't care for the Jun retainers, so if I ran Jun cams, I would run the Jun springs with someone else's titanium retainers. If you are only going to run the cams for a short while to do dyno pulls, you will probably be o.k. with the Crowers, but it is a gamble. Jun cams have broken, and I have yet to hear a clear and satisfactory answer as to what the cause was.

 

JUN cams were breaking because people were using spring rates that were not progressive. Instead they were using Portflow or Crower or Black Diamond etc... The stiffer springs caused the cam to wear extremely fast and also produced stress on the lobes of the cam. Constant stress along with higer heat allows the metal to expand and thusly become weaker. Over time this leads to the cam breaking or shattering in ceartin areas. HTH!!!

 

I don't buy that argument. CanuckMX6 was using the Jun springs and his broke :www.honda-tech.com/zerothread?id=146137
I have noticed that the reports of Jun cams breaking has dropped off quite a bit. Is it possible that there was a casting flaw in the earlier cams that Jun has since corrected? I don't know, but until I hear a definitive answer, I am going to steer clear of the Juns.







[Modified by b19coupe, 9:00 PM 12/16/2002]

 

JUN cams have been re-engineered.......