Thread: Safe max rev on SRXXVE cams

I would like to know if anyone here can tell me what the maximum rev limit for all the stock cams for the SRVE engines without valve springs. If anyone can enlighten me with their experiences let me know. This is what I have figured so far:

SR20VE-7500rpm
SR20VET-7500rpm
SR16VE- 8500rpm
SR16VEN1-9000rpm

Reason I am asking is I will be trying different cam setups on the dyno and pick the one with the most desireable powerband (highest avg in last 4000 rpm), but I want to be able to keep the head stock without upgrading springs. I won't be able to rev much higher than about 8000 rpm anyway since i have no way to tune past that point.

I want to keep the JWT computer, and be able to say the head is stock.

I want over 500whp when pushed, and power as early in the band as possible. This car will be on the track, so I need to make the most dynamic powerband possible.

there are 2 varriants of sr20ve valve springs. One set will start to float the valves with sr20ve cams at about 72-7400rpm, the other set you are ok to about 7800rpm or so.

SR16VE cams are ok to 9000rpm on stock valve springs.

SR16VE N1 cams I have seen motors at 10,500rpm on stock valve springs but not that I would recommend that.

VET cams i'm not sure as i have not measured them and checked the ramp profiling.

20V cams are ok to 8000rpm. These are more aggressive than the std cams and have more lift. Its actually just the intake cam thats the problem for valve float, the EX cam is actually fairly smooth

i dont know why people dont install springs anyway, its just a small price to pay for insurance.
Its all well and good to be able to brag that its a stock top end, but i'd rather install them than lunch a motor.

most people don't install them because they don't know how

That's true. I found a guy in my area who did the job for me in an afternoon. Bought some pizza & wings, chilled for the day and I got BC S&R's installed with my cams even though SR16VE cams don't need it. Now I can upgrade to N1's fairly easily, if the time ever comes. I see it the same though, it's worth having the insurance on KNOWING it's done, you know. It's not necessarily a hard process, just takes some patience and know-how.

I think the max rev is actually partially determined by the rod bearings and if they have a tendency to fail or not at constant high RPM shifts. Just a thought.

how god are the facory retainers ....I see some sites just selling the springs , not the retainers , I thought the retainers were pretty much mandatory

This is true but there are sooo many places online that tell you how to. If you have a few thousand dollars into a motor and you want to make max power, why not install them. It is a small price to pay. I put them on my DD DE when I put the stg2 cams in becasuse i didn't want to drop a valve.

there are a lot of things people cheap out on I know people will still pay $200 for a cam install and a DIY guide has been around since '02 at least when i did my JWT S4 swap

Retainers are not needed. If you are going to be reving high, such as 9000rpm or higher all the time, I would highly recommend the retainers as this removed weight from the valve train. Springs alone is cheap insurance for a miss shift in any event especially in a turbo application where if you press the clutch is slightly too fast you can have a over powered inertia over rev. This is where you are in boost WOT and press the clutch in too fast before lifting the throttle. With the engine making say 500hp at 8000rpm and you press the clutch in, there will be so much horsepower to spin basically just the crank and flywheel, you will easily over rev the motor. In this case the rev limiter does not do much good most of the time.

If you want to keep the stock springs, your best bet is to go with sr16ve cams because of the ramp profiles. They are very smooth and the harmonics that cause the valves to float is at a much higher RPM so valve float is moved up to higher RPMs.

Snickers, How do you know which valve springs you have? My 20ve feels like it would most likely float up 7700 or so. The motor is a 98.