99 Black Bird T/A

iTrader: (4)

For me it's more of I don't want to deal with it more than once a year period. I usually drive ~20,000 miles a year so say 25,000 miles min. My 99 T/A only saw 6,000 miles last year so at that rate valve springs every ~2-3 years seems very reasonable to me for a decent heads and cam car.

Cal

iTrader: (1)

I agree . . . Besides the reasons already mentioned, any time you increase the stroke of a motor, piston speeds increase, and that increases cylinder wear and lowers the rpm the engine can turn before it throws a rod. And increasing the bore will make the block weaker and more prone to flex under stress. Having said that, the C5R 427's seem to be doing pretty well.

Slowhawk

iTrader: (12)

I voted 10-15k for my setups.Figured they get week from the passes I do and it's cheap insurance to change them.

TTopJohn

Thanks y'all - I knew all that, but considered them problems with easy solutions.

piston/rod angles? Don't go any bigger than 4.00 stroke

Dropped Sleeves? Don't buy an all bore engine for a few years, wait until they've sorted that issue out and let someone else be the guinea pig.

Increased piston speeds? Lower the redline, or keep it at 6000rpm. Or put it at 6500, but don't go there often.

Block more prone to flex under stress? Sounds like a non issue for a N/A application - and if you're on boost you're going to lift a cylinder head before you flex the block.


There may be reliability/longevity issues with stroker's and all bores, but you don't encouter them with a mild setup.

99 Black Bird T/A

iTrader: (4)

The Darton thread in this section makes it appear that the wet sleeves will work without issue IF you have the right CNC machines and programs to do super precise machine work and a top notch machinist in a controled enviroment. So I think it might be sorted out...guess we'll see over the next year...

roy

50,000 to 75,000 min for me, Road race and auto cross and see a lot of miles . It has to a certain degree of reliability for me, not max power.

99-LS1-SS

Explain to me how increasing the stroke increases the piston speed. To me it seems like increasing the stroke only increases the distance that the piston travels instead of the speed at which it travels. The extra torque that you get from a stroked motors is from the piston being in its power stroke longer than the engine with the shorter stroke. I agree with the statement about throwing a rod at a lower RPM with stroked motor but, I don't agree with your explanation. If I am wrong then someone explain why I am wrong. Just curious. I am not trying to criticize you in anyway I just want to make sure that I understand what you are saying.

Cal

iTrader: (1)

As you mention, increasing the stroke increases the distance that the piston must travel. The amount of time that the piston has to travel this distance is determined by engine rpm. So at any given engine rpm, the piston must travel farther in the same amout of time that the stock setup had, therefore it must travel faster to do that. This also means the piston must accelerate through it's travel harder since the piston changes direction, putting more stress on the rod and rod bearings due to higher inertial loading. If the engine is both bored and strocked, the pistons also have more inertia than before (due to higher weight,) compounding the situation, so you could expect less life from the rod bearings in a 427 even if it isn't driven hard. But don't get me wrong, I still want a 427 LS engine inspite of this!

v8maro

iTrader: (4)

i voted 15-20k.

I already broke 2 at less than 5k, and it sucks.

I would really like to see some springs on my DD car last that long.

-Steve

boomcase

Im gonna say 5 to 10k , that is what I hope for on my next set of valve springs, My last set of 02 ls6 springs did great for 400 miles LOL now I invested in some manley springs and ti Retainers . Im pretty hard on the car and I spray it so Id be happy with 5 to 10k.

killer01ws6

I said 40 to 50K but I would be happy and cross my fingers for 40K.
I will be going with the TR230 cam with dual springs and Tit Rets. I know allot of people say that dual springs are over kill for a 575/563 lift cam..... but I want over kill so maybe I can get 40K

2001CamaroGuy

iTrader: (6)

I personally don't want to have to replace any sooner than 20K (10K is NOT acceptable to me).....I have 25K on my 987s (TR224/224) and when I rebuild (soon) I will be replacing them.