what rpm can it take?
 

How high can and should I turn my engine? I have plans on getting it on the dyno soon to see where it starts to lose power. But I am curious so I had to ask. Here is the combo,92' 302, 0 miles,tfs trackheats,tfs stage 2 cam,ATI damper,frpp hyd lifters,all stock internals+arp rod bolts,hi vol oil pump,victor jr,proform 650 carb,1.6 tfs roller rockers,blue pump+adj reg,6an lines,all msd stuff,c4,4.10's. I only was planning on around 6k but can I run this thing higher? or will I bring it home in pieces...? :confused:

Re: what rpm can it take?
 

Don't think you'll gain anything after 6000-6500.

You didn't say it was balanced either. The dyno will show you where the power starts to fall off, you'll be surprised how low it maybe.

Re: what rpm can it take?
 

He may be right about the power falling off at or before 6,000, but you can definately wing it higher then that before you have to worry about her coming loose. I would imagine you wont need to go much above 6,200 to see the best results, but the dyno will tell for sure. Your valve springs may limit your top rpms before you would have to worry about the engine coming apart.
Ryan

Re: what rpm can it take?
 

That Victor Jr. will want to breath. I'm betting that you won't see peak HP until after 6400. I used to spin a similar motor (50-oz balance included) with a Stealth intake to about 7100. Valvetrain stability will be the key. Remember that volumetric efficiency improves with RPM, so spin that sucker as high as you can.

Re: what rpm can it take?
 

Jeff, would the hyd lifters be my problem with valve float. I just put in a new set of ford racing lifters when rebuilding the engine. The tfs trackheats are equiped with better springs (I guess). Now that it's all said and done I should have done a few things different. But I did'nt want to get in over my head.

Re: what rpm can it take?
 

Obviously the dyno tune will tell you what you need to know. But I'd shift at about 6K rpms if I were you. My combo is in my sig. below. I shift at 6K. If I bring it up to 6300 my valves start to float. I'd imagine yours would float around the same rpms as mine.

Re: what rpm can it take?
 

Hydraulic (and especially hydraulic rollers) are a significant limiting factor regarding engine speed limit. I've seen this on engine dynamometers and heard it by word-of-mouth from local gearheads. I can't say I've ever had my motors up that high since I've usually built mine for low-end torque and reliability...plus there's that darn 6250 RPM limiter on the Mustang's EEC-IV. :(

It makes perfect sense if you have ever had a hydraulic roller in one hand and a regular hydraulic in the other. The mass difference is amazing (relatively speaking), and if you've ever seen the internals of an engine while it's running, you'll better appreciate the abuse engine parts must withstand. Imagine having that lifter in your hands and shaking it back and forth about 3000 times a minute (equivalent to 6000RPM). Honestly, that's not even close to the stress the lifter undergoes, but you get the idea. :D

Hence why I'm going solid roller when my project takes off after college. :rolleyes: :cool:

Re: what rpm can it take?
 

I went with a solid roller cam for that reason too. Still figuring out what the engine wants as far as RPM goes, but to date it still pulls HARD at 8,000! :D Not sure I want to push it any harder than that, but no valve floating issues, just "scared" about a V-8 turning that hard.

Re: what rpm can it take?
 

Done right, the hydraulic rollers are NOT a limiting factor. I used to routinely spin STOCK lifters to 8500 rpm with higher spring pressures (and more duration) than most will run even with a solid roller cam. The Victor Jr. intake and carburetor combination wants to breath, RPMs is how you do it and RPMs are where you build volumetric efficiency.

Put it on the dyno and see where peak power is at. If the valves start to float before you get to peak power, then make some adjustments in the valve train. Set the preload at no more than 1/4 turn and a simple set of restricted pushrods should solve the majority of lifter-related issues. Valve float is generally related to the springs though, but there's always another set of springs that will solve that problem.

As far as spinning stock parts, I used the same stock crank for all of 2002 and 2003 in my Street Warrior motor, one year at 50 oz-in and one at 28 oz-in, shifting at 7200-7500 all season, both seasons. One year in a stock block, one year in a B-50 block. Crank never broke, sold it when I bought a Scat crank and as far as I know the guy who bought it is still using it.

Re: what rpm can it take?
 

Jeff, you're right; valve spring pressure is vital to the stability of the engine as speed climbs. However, you probably also realize that most people don't want to change valve springs (one of the most overlooked parts, imo). Also, that higher valve spring pressure creates more drag on the engine, which is why I like the solid rollers so much. Consequently, if you're spinning in the 7k+ range, that drag becomes inherent to the territory you're in, right? :p

I suppose while we're on it, this is kind of like the whole question regarding the "maximum lift" you can have on (insert cylinder head manufacturer name here) heads. It's not about the lift, it's about the timing of the events that's important. So, you're absolutely right on about the duration, which is typically closely linked to the ramp rates of high-rev cams. :D

Re: what rpm can it take?
 

gentlemen, you all have me wondering now how high I should be shifting my 331, 28oz balance, Trickflow stage 2 cam, double valve springs custom pushrods, extrude honed Vortech intake, ported TW heads, aluminum flywheel, 4.10 gear, aluminum DS, full exhaust, the works, crane ignition is adjustable and is set for a rev limiter now at 6200, think it would be safe or smart to open it up to lets say 6500? I know the dyno would be the smartest but relatively speaking I should be ok right?

Re: what rpm can it take?
 

Without a dyno to go by, is it still pulling nicely when you shift at 6200?
Ryan

Re: what rpm can it take?
 

yet to find out, still breaking it it....

Re: what rpm can it take?
 

After you get it broken in, test it with a G-Tech to get a hp/torque curve read out. Not as good as a real dyno test, but will give a good idea as to what rpm the power starts to nose dive. Borrow the G-Tech from a buddy if need be.

Rev

Re: what rpm can it take?
 

Dude, them strokers like to SPIN! Right now I'm launching at 6000 and shifting at 7500. After you get it broken in, take it out and beat on it. Especially with an aluminum wheel, that thing is gonna rev FAST, and more importantly, it's gonna like it! :D

Re: what rpm can it take?
 

Broken in = 20 minutes at 2000 rpm at low load. After that it's time to let 'er wail! If the oil is warm, stand on it and see where it starts to drop off.

Re: what rpm can it take?
 

Now that the break in period has been brought up, How long should a new motor be broke in? Everyone has their own version. I have run my new motor for 15 minutes on the first start up and total time is about 40 minutes. Most being on jack stands with the wheels turning. (new tranny too). Also changed oil once and opened a couple of oil filters to check for debris. Found nothing abnormal. I am wondering if I make a few laps down the track at slow speed (to make sure the wheels are going to stay on) if everthing checks out can I hammer on it? or should I get some good run time first? :)

Re: what rpm can it take?
 

I was told 500 miles with non-synthetic oil for parts and seals, after 2k you can go synthetic. I hear lots of different things though.