You wouldn't happen to know who sells the 9.5" pulley would you? I know the ASP 8# is 10.0"

 

1. The Eaton is past its efficiency curve stock. It is way past its efficiency curve with pullies. Can lead to detonation, which is the curse of death for a blown engine.

2. The Eaton is overspun stock. It is dangerously overspun with pullies. Can lead to blower failure.

Don't really need a third reason. It's simply easier to get reliable performance when you are working within the performance envelope of the machine.

I had a VW bus that would raise the front wheels off the ground. But the cams shook so hard that they would rattle your teeth at idle. The heads would have warped and the case cracked over time (neither happened because I forgot to fully tighten a fuel banjo -- RIP).

 

It's a guy thing.

 

I just put a JLP 8# lower on my L, its a bit smaller than 10". I also dont plan on changing to another blower. Hopefully next summer ill do a built block, monster box ,cams, some porting and a 150 shot. That should get me into low 11s.

 

Back in 99 it was said that pullies were a waste of time(remember) because the Eaton is already at it's limits...Hummm looks like we should not put any pulley on our engines...

How many Eatons have you heard of blowing up or failing? Stock Eatons are a dime a dozen these days.. For guys who don't want to ante up for a KB and have a sound vertifiable tune AND their L's are not daily drivers AND they realize the risk I think it's an option while heading for a 11 second timeslip...JMHO of course..

 

We have no disagreement here, Jeff. I never said that the Eaton was at its limit, only that it was already past its efficiency peak. As any engineer will tell you, running a blower past its efficiency peak is not advisable when a larger blower is available. Why ask the Eaton to do more than it was designed to do when a more suitable blower can be used?

I realize that stock Eaton failures are rare, but blown rods from detonation are commonplace. So commonplace in fact that the myth has set in that the rods are "weak."

You can get more HP with pullies to be sure. But you can get even more HP by using the right blower to begin with. As you correctly assert, with a safe (i.e., dyno tuned) chip and the ability to deal with a blown engine, bumping up the boost on the stock Eaton is a viable alternative. But it's still suboptimal. I suspect that you do not disagree.

 

Tim, allow me to pose this question. I just recently purchased a KB to sit atop my stock engine (internally). My reasons for doing this were for efficiency, as I don't plan on running more than 13-14psi of boost on a SAFELY tuned chip....Is it more stress on an engine internally with 14psi and an 11:1 A/F producing 450rwhp or 12psi and a 12:1 A/F producing 450rwhp (assuming no detonation is present at either boost level)?
The combo I was running with my Eaton(12-14psi depending upon air conditions) for the last year or so yielded 400-420 rwhp w/ consistent 12.0-12.2:1 A/F ratios.
Just wondered what your take on that would be as I'm trying to get the KB dialed in as SAFELY as possible.

Thanks in advance,

Rob

 

I agree at 17 or 18K rpms the Eaton is not optimal. With that known though and at those same rpms with a good tune AND at 1/4 mile at a time Big pulleys are an option that will get you into the 11's without spending the extra 3K for another more efficient blower. Not to mention people who are looking for these kind of timeslips usually don't drive their L's everyday.. All I'm saying here is big pulleys are an option that will NOT blow your stuff up. Their are many many people out there running 6 lbs plus pulleys on stock long blocks and they are happy. There are some though that don't have the tune right and will blow a rod...I have seen that.. Running 11's with the stock Eaton is very rewarding...especially when you did not buy another better blower. Like I said these spare tire pulleys are an option that people are and will be doing... I'm speculating that you are in disagreement but that's your perspective and I listen to all views.

 

All I can say is I daily drove my 11 second L w/ an 8# lower and every other bolt-on I could get my hands on for about 10,000 of my Ls 25,000 miles ( @ 5000 miles I got a 4#, then a 6# @ 10000 and a 8# @ 15,000 miles).
I drove in the dead of winter, Long (500 or more miles each way, numerous times) trips and a lot of 1/4 mile passes w/ my stock eaton and stock internals and all on the same tune, thanks JDM(except for the 4#). Yes I have had the same tune for 15,000 miles and in all kind of conditions.

So in my opinion Ford did a nice job w/ the L package, blower and all.

Of course I want more so now the KB goes on and the internals go in.

VINNIE

 

This is what I think. If you want to go all the way out and do 10s get a better blower. But why get a better blower, built motor, and have mild boost and a mild tune?

 

It really depends on what you are doing with the truck. I do not drag race, I road race, so what will survive a 1/4 mile pass is of no importance to me. I need something that will hold together longer than 11 seconds and doesn't require $5/gallon fuel.

If I had a built block, I would use MAD boost, but a mild tune. Boost does not kill engines; detonation kills engines. Cylinder pressure even under extreme boost conditions is much lower than even mild detonation.

 

In terms of cylinder pressure, A/F is only useful in keeping detonation at bay. Thus, assuming no detonation, there would be more stress with the 14 PSIG setup than with 12 PSIG. But, if you keep detonation away, and you keep RPMs reasonable, the stock block is plenty strong for 14 PSIG. Add just a little detonation, though, and all bets are off -- cylinder pressures go through the roof. A detonating 10 PSIG motor is under an order of magnitude more stress than a non-detonating 14 PSIG motor.

I don't see any problem with 14 PSIG from the Eaton. As measured by the Auto Meter electronic boost gauge, I see 10.5 PSIG consistently with my bone stock '02. Many, many people reliably run 4 lb. pullies with no chip. Run too much timing or too many RPMs with a chip, though, and . . .

 

Sweet my post has good info !!!!! hahahahahah!

 

cause I am Nuts

 

Don you dont count !!! You have a fully built motor ! Not a KB-wipple replacement for the Eaton........