Stock heads/rotating assembly, hot cam/vlave springs- how far can you go?

AJ/FormS said
I just wanna say this
Backroad hooligan driving used to be my passion too. But I kept it below 50 mph, cuz our ditches are often,mostly; deep and steep; And I know what a sudden stop feels like at 30 so I wasn't interested in finding out anything more than 50.
That said, my backroads are gravel, and I had 3.55s with a 4-speed. So for me 50=4200,40=3360. So for me, power at 5500 didn't mean spit.
But for you with 4.10s and a 1.45 second gear , 50=3900 @5% slip, even 60=4650@5% slip, so again, power at 5500 don't mean spit.
Those 4.10s will hit 5500 at about 71 mph. So if you're blasting gravel backroads at 70 plus mph , you're either waaay braver than I ever was, or IDK what either,lol.
But on hardtop, Ok I concede the point.... but then the question is; how long are you expecting your engine to last, blasting at 5500?
I did that one time, and said goodbye to #1 rod bearing. Another time #3 went out.
Have you done any oiling mods to her?

You know a 318LA-2bbl cam will rev to upper 5000s right. It just takes the complimentary valve gear. I mean it won't make much power up there, but it will rev to there.
Be careful what you wish for; Rumble posted a well-thought-out answer.

Ripping around on gravel roads sounds like an absolute blast. I'm with you on pulling it back a bit where the consequences of a mistake get scary...I'm definitely not braver than you. I know my limits and the limits of the car and that has always kept me safe (so far!) but I'm no professional driver!

I hear your point about how useful power may or may not be at a particular RPM...that's very valid depending on the application. For me, the local backroads that I enjoy are all paved. I have this one amazing up-hill country road with a series of three chicane like turns in it. Getting down the rhythm of the road, keeping the engine right in the power band, ready to blast off on each corner exit has been so much fun. Being an up hill stretch allows me to put down more power longer before going into orbit. It's a great piece of road but so far, the Dart just doesn't have the punch to make that road as much fun as it has been in other cars. I'd love to be able to hold 1st gear a bit longer and do more than just make noise above 4.5k.

How long do I expect the motor to last? Well, I didn't think that 5500-6000 was overly stressful for this rotating assembly and I didn't anticipate any premature mortality for the engine. I don't plan to hold those RPM for prolonged periods of course but your reports about losing rod bearings are worrying.
So far, I am on the stock oiling system...am I gathering that this is a significant vulnerability.

RustyRatRod said
Crate engine companies work within some fairly restrictive parameters. The end result has to satisfy the customer, while making the company a decent enough profit to cover all their costs involved and make money on top of that. So, you can bet there is room for improvement. I'll use Blueprint, for example. None of their engines come with any type of solid lifter camshaft. We all know which can make more power, everything else equal. They do that, ultimately to cut down on errors the customer might make and to help assure a good, successful installation and engine break in and good, dependable service. Lets face, it a hydraulic cam engine has room for fewer things to go wrong, since valve adjustment is generally not done except after initial break in and all of Blueprint's engines are pre-run, so all of that has already been done.

That being said, as I've said a lot before, "whatever" engine you build will have some power somewhere left on the table. That's just "how it is". To me the question would be can you come up with a better all around package, including dollar spent, verses value and reliability. Maybe......maybe not. It all depends on "how good" the crate engine company is. IMO, Blueprint is now probably one of the best.

Good points here. I guess the idea is to be slightly less conservative than the engine makers and reclaim a piece of that performance that was left for the sake of durability but not so much that you smoke your engine.

Often you'll see this with late model cars. Tuners are confident enough to go slightly more lean with AFRs or they're willing to raise a redline a little. It would be a risk for the OEM to tune this way but individual owners may know enough to push the limits.

JunkyJimmy said
I did a cheapy 5.9 many years ago, $100 running core with 185000 on the clock. Both heads had cracks Ray Charles could have seen, a few exh guides were a little loose, cam bearings were toast. Everything else looked good. Ball honed it, cam bearings with 1/8" holes, simple valve job, hot pressure washed it all. Reused heads, valves, rockers,oil pump, and rest of short block. Pistons were all 053" ish in the holes. China air gap,Oregon regrind, 1121 head gaskets, hughes springs and retainer kit, pushrods, fuel pump thingy, $35 timing set. Napa cast rearing kit, homemade pan and pick up,spent maybe 2 hours smoothing out the pockets and took 3/8" off bottom of intake guides. Old girl runs like a beast for what it is, kind of wish I would of put valves in it, but didn't want to spend the dough, have a little over $1000 in it with some elbow grease. No machine work except for the valve job. Turns low 6s all the time,(rpm). Really thought it would have spit the bit along time ago.

This is encouraging...
It sounds like the stock oil pump is holding up which is good to hear. Does your custom pan/pickup offer any advantage over the car style (LA?) type pans that most of us use? IIRC, these pans do not have a windage tray...

roccodart440 said
IMO it's worth getting the RPM airgap. I believe it's the best option. Even if it's "nearly as good" it's worth having the best on there. PLus there is the air gap as an advantage as well.

I hear you on this. I suppose that this manifold can be transferred to the next motor anyway.