When should I put the car on the dyno for the tuning after the new motor is in? The builders want to dyno tune it right away and I've heard that's not a good thing. It will definately need some driver friendly tuning before it leaves.

 

Give it a couple of heat cycles, and hit the dyno.

 

I'd give it at least 1000 miles before strapping it down

 

Why? There's nothing to break in in a roller motor. No need in possibally washing out the rings due to improper tuning if there's no reason.

 

When I had my motor built, I was told to get at least an oil change in it before strapping it down..

Why would the rings get washed out? Granted you add more fuel to the combustion chamber to cool the cylinders to keep them from detonating but you don't need to pour fuel in them.

A break in tune is just that. Get the car to start and let everything seat, then let er rip.

Just my opinion...

 

IMO no real reason to run it 1000 miles. most people are not building a high performance motor to DD it. they are there to race it/beat on it.

 

this has been discussed a lot in the internal engine forum...

http://www.mototuneusa.com/break_in_secrets.htm

do a search for more topics on this subject.

 

A couple heat cycles and hit it hard !!!

 

Get a couple heat cycles varying engine rpms, lotsa 2000-4500rpms acceleration and then engine break back down, check for leaks, change the oil, WFO on the dyno!!

 

Put a couple miles on it, check for leaks, strap it down!

 

I know if you ask 4 engine builders, you will get 5 opinions.

But... my engine builder said to do the initial fill with straight 30 wgt. Gently take it up to 70 MPH and then motor brake the car by downshifting through the gears. Do that 10 times at least was his instructions. Then put 500 moderate, varied RPM miles on it. Change oil (to what I normally use). Then drive it like I stole it.

I did the whole 70 MPH downshift thingy about 20 times and have put only 100 street miles on it due to weather, cops, etc. But I respect his opinion and plan on following instructions.

 

This helped me out and made up my mind. Which it also makes senses. My last 3 LS1s I broke 'em in hard and they all seemed to be good running cars for me. I don't see why this one would be any different. Thanks.

 

Think about it like this... most of the hi-perf or race engines that we have built just like thousands of others, the starter on the dyno is what cranks them for the first time. They are run a few cycles to break them in, change the oil and then run em. So even though you are on a chassic dyno the engine doesnt know the difference. Sleep well.

 

You will love the torque this new motor makes. You need to get some tires!

 

On My 347 I Turned It On And Rolled It On The Rollers Did Some Tweacking On The Tune And Then Hit It With Full Pulls On A Mustand Dyno And It's Still Holding Up Damn Good.