Dyno do’s and Dyno don’ts

[BigDaddy72]

Have you ever had an engine dynoed?

Chassis dyno or engine dyno?

Good experience or bad experience?

Are engine dyno’s bad or “rough” on engines, or is The operators knowledge the part that is bad or rough on the engine?

Is any of the above valid or true?

I currently have two 496’s one I would like to engine dyno and one that I would like to chassis dyno.

Additionally I will be posting my 572 engine build. I would also like to dyno it.

I like the idea of taking a scientific approach to tuning an engine to its safe maximum capabilities. Removing all guess work.

I created this thread to have input by all and not to hi-Jack or clog up Mark Jones build/dyno thread.

I posted a comment about a local shop that has broke the last 4 motors they have had on the dyno.

I have always been told “engine dyno’s are rough on engines and can brake a good motor that would otherwise have a long life.

What should I or what kind of questions should I ask a dyno shop that I may be considering?

How can I be sure they are competent at their job and my engine does not get damaged because of faulty equipment or user error??

Anyone with any experience/knowledge or opinion please please chime in.

 

[Camar068]

Curious as well cuz I don't want to have to replace what I've got.....and listen to the wife bitch about it. If one EVER burned out during a dyno, I'd never do it again.

 

[Green79Scottsdale]

The dyno itself is not hard on the motor. Where you get into problems is with the tune on the engine. The dyno operator should ask about your combo so he will know what to watch for, I feel specifically about the cam and valve springs, so he gets a good idea of what rpm to cut off at. Dyno operators dont want to ruin your engine. They have a whole array of gauges they will be watching.

 

[Matt69olds]

I have never had a engine on a dyno. It’s on my list of things I’d like to do.

Personally, I can’t imagine a dyno session behing any harder on a engine than full throttle street abuse. On a dyno, you wouldn’t have acceleration or braking forces sloshing oil around in the pan. You would have far more diagnostic info than you would ever have in a truck.

Some people think rings seat better with the engine under a slight load. The theory makes sense. Not to mention being able to fine tune for best performance under repeatable conditions, all around win.

 

[Rusty Nail]

My opinion has to do with what I perceive to be widespread use of too much valvespring seat pressure so builders can blame their wiped cam lobes on new motor oil.

I urge substantial consideration given to valvetrain component selection and proper installation.

How many of the last 4 motors were vortex headed?

 

[RecklessWOT]

I prefer chassis dynos myself. In my opinion, at the end of the day it doesn't matter how much power an engine makes if it can't put it to the wheels. I also feel they give a more real world scenario since they're already set up exactly the way it will be when going down the street after you leave the shop

 

[Camar068]

I prefer chassis dynos myself. In my opinion, at the end of the day it doesn't matter how much power an engine makes if it can't put it to the wheels. I also feel they give a more real world scenario since they're already set up exactly the way it will be when going down the street after you leave the shop

Thanks All for the info....I feel a bit better.

 

[BigDaddy72]

I m not really talking about how an engine is set up.

Any engine that has problems (too much timing, lean, too much spring pressure, not enough spring pressure, ect ect.) will have problems regardless if it’s in the vehicle or on a dyno either engine dyno or chassis dyno.

What I’m referring to is the stress the dyno itself puts on the engine.

I’ve been told it puts tremendous stress on the engine. In effect a load that is not real world ie: what a vehicle would experience in any other condition.

I think of it this way:

The engine starts to rev to say 3000 rpm then such a tremendous load is put on it at wide open throttle that it stops the engine from accelerating and holds it there while the engine labors to start building rpm again.

In my mind similar to putting an extremely heavy load on your truck, then hitting the nitrous button and holding it there as it struggles to reach maximum rpm.

Like purging no2 at idle through the motor, I know of a lot of guys say it’s not going to hurt anything but it’s not something I would do to my engine.

I have only been told this I have no experience as to weather a dyno puts a dangerous amount of stress on an engine.

But it’s stories like that true or not is why I’m asking.

In my mind...

I don’t lack knowledge of how to build an engine or have a lack of confidence in what I’ve built.

I have a lack of knowledge as to how an engine dyno works and a lack of Experience with one and that is enough to scare me away.

But if you don’t ask you don’t know

I want to make an educated decision before I throw a $10,000 engine on one turn someone I don’t know loose on it and hope for the best.

I certainly don’t mean to sound disrespectful to anyone and am not saying any of my statements are true.

So please don’t take offense, I’m not the best at getting my point across in writing.

Hopefully I explained my questions better.

 

[BigDaddy72]

My opinion has to do with what I perceive to be widespread use of too much valvespring seat pressure so builders can blame their wiped cam lobes on new motor oil.

I urge substantial consideration given to valvetrain component selection and proper installation.

How many of the last 4 motors were vortex headed?

I personally don’t know all the specifics and keep in mind this is what I was told I have no proof just second hand information.

It was said they were high dollar big hp motors so doubtful any were equipped with vortec heads.

Because I have no personal experience with this shop I don’t want to and wouldn’t imply that the statements are fact.

Just what I was told “stay away fro them.....”

 

[OldBlueDually]

@BigDaddy72 will the dyno people break in your engine, or is it already broke in? I would want to be sure it is broke in properly before any dyno pulls are done with it. I have never had one done.

I would ask if they are going to break it in & do an oil change before a dyno run. Also is a specific cam/ring break in additive in the oil?

I found out with mine (not a fresh build, just cam/spring update) that I cannot prime the oil pump in the engine (manufacture wants lifters to build up their own pressure), that I need to use an additive in the oil for the cam, I cannot use my center valve springs right away, and need to run it at 2,000 to 2,500 for 30 minutes just to break in the cam properly.

Then dump the oil, add the center valve springs, then drive it. If yours requires any of this I would be curious to know if they do that.

 

[OldBlueDually]

I m not really talking about how an engine is set up.

Any engine that has problems (too much timing, lean, too much spring pressure, not enough spring pressure, ect ect.) will have problems regardless if it’s in the vehicle or on a dyno either engine dyno or chassis dyno.

What I’m referring to is the stress the dyno itself puts on the engine.

I’ve been told it puts tremendous stress on the engine. In effect a load that is not real world ie: what a vehicle would experience in any other condition.

I think of it this way:

The engine starts to rev to say 3000 rpm then such a tremendous load is put on it at wide open throttle that it stops the engine from accelerating and holds it there while the engine labors to start building rpm again.

In my mind similar to putting an extremely heavy load on your truck, then hitting the nitrous button and holding it there as it struggles to reach maximum rpm.

Like purging no2 at idle through the motor, I know of a lot of guys say it’s not going to hurt anything but it’s not something I would do to my engine.

I have only been told this I have no experience as to weather a dyno puts a dangerous amount of stress on an engine.

But it’s stories like that true or not is why I’m asking.

In my mind...

I don’t lack knowledge of how to build an engine or have a lack of confidence in what I’ve built.

I have a lack of knowledge as to how an engine dyno works and a lack of Experience with one and that is enough to scare me away.

But if you don’t ask you don’t know

I want to make an educated decision before I throw a $10,000 engine on one turn someone I don’t know loose on it and hope for the best.

I certainly don’t mean to sound disrespectful to anyone and am not saying any of my statements are true.

So please don’t take offense, I’m not the best at getting my point across in writing.

Hopefully I explained my questions better.

I am so fricken offended Just kidding

If I had that kind of coin stuck into an engine, I would even want to know if their parents were ********. You have a large amount of time and money in the engine, you can ask any questions you want of what may happen with your engine and how the dyno works.

There is a guy around this area that builds/dyno's engines for a living and I know a lot of his customers, they all have praise to say about him & his shop. Even then, I would still ask a few questions about how the engine would be dynoed.

 

[BigDaddy72]

The 2 496’s are custom hyd rollers from jones cam designs.

The 572 is a custom solid roller from Bullet Cams

The 468 I built a few months back was another off the shelf solid roller from Herbert Performance.

I really don’t run any flat tappet stuff anymore.

Not that I think there is anything wrong with flat tappet cams they were used for many many years and still have a place.

 

[BigDaddy72]

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Ah may as well include a couple pics who doesn’t love a few engine pics.

Solid roller with 11:1 cr massaged 781 heads 468

Hyd roller 9.25 mildly massaged 781 496

10.2:1 hyd roller afr 265 heads 496

Picture #2 and pic #4 is the same engine. Pic 4 is after final paint.

Of course most of you have seen them lol!!

 

[BigDaddy72]

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dart 572 for my 68 camaro.

I’ll be assembling it this week or next week. Depending on my work load.

454 currently at my buddy’s machine shop. That’s the one for the youngest boys 55 gasser project.

 

[CoggedBelt75]

I’ve had my truck on a chassis dyno twice. Both times were tuning sessions only. Once with the carbed engine of unknown builder that was in it when purchased. The other with the current engine which I built but with an electronic bug catcher. I have heard horror stories myself and was hesitant to trust anyone doing this. I knew nothing about either shop that was located in OKC.

The 1st time, the session lasted an hour. They ran it no harder there than I did on the street. Actually, I probably ran a bit harder. In the end, the re-jetting and tweeking the timing under varying speeds resulted in a 32 hp increase.
With the second, it lasted most of the afternoon. I’m no skilled engine builder, but I’ve assembled enough in my lifetime to be confident in that department. The parts were over the top so wasn’t a concern there. He thrashed it pretty good too. All held up and he knew when to back off and let it rest.

With me, neither operator was any rougher than me. A couple of full pulls from both, just short bursts. Kinda like I do on the street. I would like to do it again with the dual carb setup but not wanting throw the money at it or feel like I need to as I’m pleased with how I have the tune now. Could they get more out of it? I know they could. But like Kevin @RecklessWOT has already said, power is useless if it can’t be planted to the road.

May not be of help help or answered any of your questions. Just my experience with one.