So i'm looking at doing a motor build soon and taking suggestions and thoughts from people. I want a build that will spool my Red quick, and be able to rev to 8-8.5k with a 800hp capable limit.

I was looking at going 4G64 because of the extra 6mm deck height and the large bore.

Lets see what you guys can throw together, but this is what I was looking at...

4G64 With new water pump etc...
JE or CP 87mm 10:1 coated pistons
Turbo tuff rods (may look at R&R aluminum rods too)
Lightweight 100mm Crank (Eagle, K1, GSC, SBR etc...)
Balance Shaft removal
ACL bearings
ARP main studs
Billet Gridle

Motor will be balanced, blue printed and align bored

Mikey

 

The 2.4 is an awesome choice! We've been using and building it for years and it spools like a champ! It's also a blast to drive because it can be made to rev really nicely so you get HUGE torque numbers with great power.

That type of motor is right up our alley and I can definitely get you a GREAT deal on a GREAT Motor. I think you just emailed me as well, I'll get you something in writing. You'll LOVE IT!

 

Thanks Marti! I also emailed Mike...

 

Correct me if I am wrong but I was under the impression that the rod ratio of a 4g64 2.4 build would limit the revs to 7500rpms MAX.

 

Out of curiosity, what does it cost to do a build like this? $10k or so with everything?

 

The rod to stroke ratio can be improved by using a stroker piston and longer rod with a 4G64.

But I think in terms of rpm limits, it's simply an issue of piston speed. And I think piston speed is simply based on stroke. And I *think* Buschur and others have suggested you can go higher than 7500rpm on typical 100mm 4G63's..

I've had the rev limiter on my 4G64 at 7900 for over 2 years now and all is well. Hard to say how far to push these things though. I recently bumped it up to 8200 so I could ring things out a bit further. I wouldn't be afraid to go to 8500 for the track but haven't tried it so don't know what would happen.

I think the rpm / piston speed issue puts a beating on the bearings. And I think how well your motor was machined and clearanced in terms of the bearings will play a role in all this.

 

Didn't you guys do a high compression 4G64 rally car? What was the end result with that build?

 

Ryu, You can rev the 2.4L 4G64 a bit higher than a 2.3L 4G63. The reason being, you can make a better rod/stroke ratio because of the higher deck height, the larger bore with a long skirt piston will help eliminate some of the stress on the rods while eliminating piston slap that comes will 100mm strokers, and if you use an aluminum long rod it will also help relieve the stress off the wrist pin Theoretically, if everything adds up, you can make a rev-able 2.4L of 8k+

NO! You can build a decent 2.4 4G64 for 4-6k. A basic 500hp capable 2.4 can be picked up for around 3-4k.

You are correct about piston speed. however the real problem with strokers is the stress put on the rods and wrist pin. If everything is done correctly and balanced from the clutch/flywheel to the crank pulley and within close tolerance plus all the things I just listed.... You CAN make a rev happy 2.4L

Mikey

 

156mm 2.4 can spin 8500. That is the motor I would do Mike, but 10:1 on pump/meth is gonna be on the edge. I would do it if you are going to switch to E85, but otherwise a 9:1 should work pretty well.

aaron

 

Interesting. I never really considered the idea of using stroker pistons to increase the rod ratio. Seems like a good 93oct/red combo for my beater car.

 

Thanks Aaron, would you suggest going 156mm Aluminum rod? I would like to go E85 but now that is hard because there are no stations in the area. I may have to look at a 9:1... Lets keep in touch on this

Mikey

 

So improving the rod to stroke ratio effects the max rpm of the motor? Why is that?

 

i rev my 2.3 to 8500 all the time. i think more like 9000 would be pushing it! gotta have good rods though.... manley turbo tuff's would get it done!

 

Aluminum rods and a 100mm arent likely to play together. I'd do a steel rod motor (but good rods) and 9:1.

Sideloading on the cylinder wall increases as R/s goes down. Those 2.5 and 2.6 4G64s are rated to a max of 7500. The 2.5 that ACP had in his rally car was supposed to only redline at 6500. It had a R/s of 1.415 and failed. The 2.4 4G63 that Paul had back in the day was 1.47 and failed at a little over 7200.

It gives some reliability back. You still face piston speed issues vs material strength but you can push it a little further than having a short R/s.

 

off topic but whats the benefit of going with a 2.4 over a 2.3? Second another off topic question but i know JohnBradley is doing a long rod 2.2. I just wanted to know how high you could rev one of those motors and how much hp it can hold.