MOD Motor RPM

[Route666]

Imagine a 4.6L DOHC MOD motor, with a billet crank (1500hp), forged (900hp) rods, and some forged aluminium pistons, along with aluminium valves, brass valve guides, titanium retainers, higher tension springs, and whatever camshafts were required.

The standard stroke is retained.

All the important fasteners are ARP bad boys.

Also, it has Jet Hot LFC (low-friction coating) on the piston skirts, valve stems, and camshafts, and Jet Hot TBC (thermal barrier) on the valve heads and piston tops, not that this would really help rpm anyway I would think.

anyway, my question is:

What rpm would I be able to attain with such a setup? I would like to build a engine capable of 9000rpm, and limit it at 8000.

 

[SVTour99]

damn you must have some bills.....

 

[Route666]

lol not so many bills as yet, give me a couple of years, and I'll have all the money I need for this car. It's all plans so far, but its better to plan something than to waste money doing it and find out its wrong and have to end up spending twice as much to get the job done.

 

[khaine]

skip the forged rods, and go to billet rods...
make sure you get good springs for the valves and good bearings

I'm sure there are other things that I'm forgetting, but I have a 4.6L DOHC motor that lives up around 8000 rpm, and has taken a trip to 12000 by accident once...

 

[Route666]

Yeh I've heard billet is the way to go, what about pistons, what are the best to get? I figure aluminium, cos theyre light, but can you get billet pistons lol it sounds silly to me.

 

[khaine]

well I have forged pistons in mine, the billet ones are more expensive and not really required unless you want to spend lots of money for no good reason :-D

 

[Route666]

True, I suppose I'll be rebuilding the engine to freshen it up before anything forged breaks anyway, so I understand your point, thanks for the info. It's good to hear that everything survived at 12000

 

[GR8WHITE]

Your valve springs will be your biggest issue. Cam profile will also determine if spinning 9K is worth it or not. That is if you plan to be naturaly aspirated. If you're planning on boost, then the cam won't be such an issue. If you plan on the best valves go titanium, much stronger and a little lighter. An SFI rated billet aluminum flywheel will be mandatory since the stock cast iron one will not withstand much of the 9K range long. ARP 2000 hardware for the ultimate strength, and a girdle on the bottom just for good measures.

PS. Really agree with the billet rods and crank idea!

 

[Route666]

Originally posted by GR8WHITE
Your valve springs will be your biggest issue. Cam profile will also determine if spinning 9K is worth it or not. That is if you plan to be naturaly aspirated. If you're planning on boost, then the cam won't be such an issue. If you plan on the best valves go titanium, much stronger and a little lighter. An SFI rated billet aluminum flywheel will be mandatory since the stock cast iron one will not withstand much of the 9K range long. ARP 2000 hardware for the ultimate strength, and a girdle on the bottom just for good measures.

PS. Really agree with the billet rods and crank idea!

Would like titanium valves, and when I originally started planning this motor, I found that I could only get custom-made manley items, and that was a little too much for me. Now, I'm thinking I'll be able to have the custom items made, and I'll love the extra strength.

Mains girdle, agreed, I've already got this written down too, and the billet flywheel

As for the cam, the motor will eventually be FI, so I'm not worried about having a massive hardcore cam profile, with the 5.0 cammer, the lift is .510 I think anyway, so its not too bad. The springs that it comes with are bee-hived, but they're probably not strong enough for that sort of rpm, as the max power of the standard motor is at 6700rpm.

More input on parts, mods to put on this motor to strengthen it would be much appreciated. Thanks for the help so far too, this car is becoming more and more a reality to me :thumbsup: