Engine dyno - do or don't?

[Yelcamino]

To save you all the trouble of going through this entire thread, here are the results of my dyno day on 12 Oct 07:

AFR headed 468:
Peak HP - 619 @ 6200
Peak TQ - 570 @ 4800

Brodix headed 460:
Peak HP - 505 @ 5300
Peak TQ - 555 @ 4000

The print outs from the dyno are on the last page of this thread.





Original post:
This is probably a dumb question, but if you had the opportunity to run your engine on a dyno before you installed it in your car, would you do it?

The cost is reasonable, I'll get a full 8 hours on the dyno for $400.

[Tiger]

Sure Herb,

it will make you run it in, tune it and discover eventual leaks before even putting it in the car.
and yeah if you have coated headers dont use them :o)
and compared to Europe, that is CHEAP!

[Bow Tie 67]

Ditto, that way you know its dialed in.

[68sixspeed]

do it-- it's a lot less stressful having the builder fire it off, do the correct break-in, watch for oiling issues, leaks, etc. I'd much rather find a pan or main seal leak on the dyno than in the car too.

[wiedemab]

We broke my engine in on the dyno and then did some baseline pulls with a carburetor before putting it into my Mustang. After getting it into the car I had it tuned with an SCT chip on a chassis dyno. I'd rather find any issues before installing it if I could - I recommend it!

[GetMore]

In my opinion, it is not required for a street motor. Also, it will not load the engine the same way the car will when driven on the street, so tuning on the dyno will still require some fine-tuning when in the car.
Also, it's $400 that you could spend elsewhere on the car.

Now, having said that, if you're willing to spend the money I am sure you will find it worth it. You will be able to check for leaks and problems while it's still easy to work on it, you will get the basic tune set, so you can just drop it in the car and drive, and you will have an accurate rating for the power output-no imaginary power numbers for you!

Some things to find out:
Do they tune the engine for you, or do you need to do it yourself?
Will it cost more for them to tune it? ie: Will they charge for the parts?
What can they tune? Have you/they got parts for your carb and distributor?

BTW, if you're running a flat-tappet cam I think your best bet is to take it to the dyno. Their experience should ensure that it starts right up and runs right, so you won't have to worry about wiping a lobe.

[Lowend]

For $400 I'd do it. If thing thing has a leak, or eats the cam it is a lot easier to deal with NOT in the engine bay.

[Yelcamino]

Ok, ok, you guys conviced me. I called the shop and the $400 gives me the option to do the tuning or they will do it for me. Considering they set up engines for NASCAR, I think I'll let them do the tuning!

Here's the coolest part... I'm pulling the engine from the El Camino to put it in the Chevelle. The 454 I just built is going to go in the El Camino. Since both engines will be out at the same time, the dyno shop said I can bring in both engines, run the newly built one, get it broken in, adjusted, and do some power pulls and if there's enough time left, I can also run the second one, all for $400!

I'm on the calendar for 12 Oct.

[Chad-1stGen]

So how is an engine broken in on a dyno?

Is this as good for the engine as mile driving the first 500 miles or 1000 miles?

[Lowend]

A better question is
"What is engine break-in?"
What exactly is breaking in... after the first hour of run-time the engine has done all the break-in its gonna do

[Yelcamino]

Break-in is to ensure the rings seat, cam and lifters successfully unite (doesn't apply to either of mine as they're both roller cam equipped), and to set baseline timing/jets/valve adjustments. If there's more to it than that, I wasn't aware.

According to the dyno shop guy, the first thing that's done is to run the engine for about 45 minutes. Then they check all the settings, adjust the valves, timing, re-jet the carb if needed, then run the engine again (can't remember how long he said for the second run), and then check the valves once more. He said by that time the engine should be fully warmed up and that's when the power runs start. He said they'll do three baseline runs, make adjustments, and do some more runs until max power/tq is achieved.

I'm not testing different cams or intakes, so I would think I should have plenty of time to get both engines on the dyno!

[go-fish]

I am going to be dyno-ing my blown 408" around Nov. All I am going to bring to the session is a Wilson Manifolds carb spacer. I might buy another intake between now and then. I have a single plane and may try out an Air Gap dual plane. My rate is slightly higher but like you, I just want to have a pro break it in, find potential probs., and get an accurate bragging #.
I agree with everyone else, if it's there, go for it. Plus, you're getting a deal.

[Tiger]

Cool Herb,

that is cheap I'll put my engine in an envelope and mail it to you toghether with a $400 dollar bill, then you can do a pull or two on my engine as well and put it in your suitcase if you ever move your A** and come to Europe.
after all its a smallblock so it should fit.

[Scott Parkhurst]

Consider this...

You have a new engine. You bolt it in, turn the key, and it won't start. Or, maybe it won't even turn over.

Is it the engine, or something else in the car?

If you dyno it, you know the engine is fine, and should start easily and run well. If it does not, then you know it is something else in the car.

If you do not dyno it, you've got a lot more work to do diagnosing and double-checking everything you thought was done already.

If the leaks and adjustments aren't enough encouragement, maybe the 'not starting' scenario will cement it.

I am quite sure I will dyno test every engine I ever build from now on. It's the best $400 (or so) you can invest into your car, IMO...

(...but, I'm an engine enthusiast too!)

~SP~

[Yelcamino]

Looking back over the years, these two engines are the 12th and 14th engines I've built. They will be the first engines I've ever had run on a dyno so this will be a new experience for me and one that I'm really looking forward to!

As you guys have mentioned there are a lot of pros to the dyno and very few cons, if any. I've experienced the leaks and not starting issues in the past and I've overcome all of them so that's not a big deal to me. The real reason I want to do this is because I'm tired of guestimating hp & tq. I want to know what my engines are actually producing!

So, the evening of 12 Oct I'll be posting the results. Hopefully they're good!

[fishtail8]

Going to the dyno also makes bench racing sessions, and racing sessions more exciting when the guy next to you brags about having 500hp. Then your car, which you know only makes 400hp, whups his!!! We dynoed my 406 with stock rockers and no carb spacer, then swapped to 1.6 rollers and a spacer, ended up finding out we added 35hp... Try some different aircleaner lids if you get a chance. One of the lide with the domed top seems to help a bit....

[Yelcamino]

Trying some easily changed parts suchs as carbs, spacers, and air cleaners sounds like a good idea. I have three carbs and two styles of air cleaners I can try. I was also thinking about getting one of those tapered carb spacers from Wilson Manifolds. Who knows, maybe one of these things (or a combination of things) may yield a substantial power improvement.

[Mike Holleman]

Well we know for sure that the Elky engine makes enough power to remove all the teeth from third gear in a TKO500. Maybe soon we will know exactly how much power it takes to do that. I am curious about one thing, why the engine exchange?

[Yelcamino]

Well we know for sure that the Elky engine makes enough power to remove all the teeth from third gear in a TKO500. Maybe soon we will know exactly how much power it takes to do that. I am curious about one thing, why the engine exchange?

Hey Mike,

I'm swapping engines because the Elky is what I call more "showy" than the Chevelle. I figured I would put the more docile engine in the Elky and use it as cruiser/car show car and the uncivilized engine could go in the Chevelle and I'd use that to beat on.

[Jims78elky]

Absolutely do it Herb!

To get the new engine dialed in and tweaked would save you
a huge amount of time..and you definitely know what it makes.

Leaks..bugs,burps..agravation all gone for $400.00 let them
take care of it for you,drop it in with no grief,or any issues.

Very cool!


-Jim