Quote:
Originally Posted by YerDugliness
I am planning a rebuild of my SBF engine soon (a 1989 8.2"/5.0 from a Mustang GT), and as I plan it out, I'm thinking about using some of the available engine treatments. I'd like to hear from others about the engine treatments they have used and liked.
Specs for the new engine will include good forged internals, aftermarket heads, the standard stuff...I hope to be able to rev the engine to 6,500 RPM's on a regular basis without worrying about it self-destructing.
The sort of "treatments" I am asking about include things like nitriding the crank, "teflon" coating the pistons, that sort of thing---and I am most assuredly interested in learning about the multitude about which I am unaware, as well. Not looking for advice on which brand of crank/pistons, that sort of thing.....unless there is a "treatment" you recommend that is only available on a specific brand of equipment and is not available in the aftermarket. I'd also appreciate an explanation regarding why you recommend a specific treatment so that I understand how it will make the engine more powerful/durable  .
Thanks in advance for whatever helpful suggestions you can make!
Cheers from Dugly  |
Piston speed in feet per minute is what limits what RPM you can rev to. The formula for piston speed is:
RPM * Stroke (in inches) * .166
In the case of a 5.0L engine the stroke is 3" (someone correct me on this if I'm wrong):
6500 * 3.0" * .166 = 3237 feet per minute.
In general an engine from that era with stock internals redline will be set at any piston speed between 2 - 3000 feet per minute.
An engine with good quality aftermarket parts (specifically the connecting rods and rod bolts) will rev to between 3 - 4000 feet per minute.
High performance and racing engines in which long term durability is not important will be between 4 - 5000 feet per minute.
If you had good internals in that engine you could easily rev it to 4000 feet per minute and have the engine live a reasonable amount of time. This would correspond to 8000 rpm.
Of course to do this you will have to run correspondingly high quality valvetrain parts and stiff springs to allow it to rev this high.
As far as 'treatments' I don't necessarily think they are necessary on a street engine but if I were to go with anything it would be a low friction coating on the piston.
Ceramic coatings on the top of the piston should be paired to ceramic coating of the combustion chamber in order for it to be effective. However the gain on a street engine may not make it worth it.
You should buy a good forged crank, it may be hardened by nitriding or it may be induction hardened.