What is the HP rating for a stock 1968 to 70 Toronado 455?

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UV520
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What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby UV520 » Mon Feb 17, 2020 10:31 pm

Hello Everyone,

I hope you project(s) have been going well.
It's been a long time since I was last here. Life has kept me from my projects.
But now I'm able to get back at it and I want to play catch up as fast as I can. Grin

I'm designing a hydraulic cooling system for my odd ball project and I need to find out what is a true HP number for a factory 68 to 70 Toronado 455.

Is it 375HP or 400HP?

FYI - 25HP more produces 63,611 more BTUs of heat... And this is why it is important to find out.

Thank you a head of time.

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Otto Skorzeny
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby Otto Skorzeny » Tue Feb 18, 2020 6:15 am

What do you mean by true hp? None of the figures published by automakers in the 60s can be considered accurate.

They were theoretical numbers based on engines without accessories or transmissions. Basically it was the engine performing no work at all. In reality, the actual "to the wheel" power output was much less than the published numbers.

What is the downside if you assume the higher number in your project?

UV520
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby UV520 » Tue Feb 18, 2020 7:41 am

Otto Skorzeny wrote:What do you mean by true hp? None of the figures published by automakers in the 60s can be considered accurate.

They were theoretical numbers based on engines without accessories or transmissions. Basically it was the engine performing no work at all. In reality, the actual "to the wheel" power output was much less than the published numbers.

What is the downside if you assume the higher number in your project?


This overheating issue has kicked my butt and I spent the first couple of years trying different things.
I believe there might even be a post on here about some of it.

To answer your question: "What is the downside if you assume the higher number in your project?"
Similar to a house HVAC. If the system is over built it will not work properly. Plus it will also cost more.
If it is under built, it will have to work harder and may end up being a waste of time and money to install and not solve my problem.

Maybe I can ask the engineer who is helping me if it really matters. But he is the one asking what the HP is...
I've found ratings of 375hp and 400hp...
FYI - The 25hp different equals an additional 63,611 BTUs of heat to have to deal with.
The overall cost to begin with is over a thousand to get a good hydraulic cooling fan setup.


NOW, I could throw stuff at it, by using other manufacturers' parts and try this and that.
But I've been there and done that.

I've even gone to great lengths to have Computational Fluid Dynamics preformed in regards to the air flow around the coach it self and through the engine compartment and radiator.
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UV520
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby UV520 » Tue Feb 18, 2020 8:33 am

Here is the big old 455 in the back and note the radiator is behind the power-plant and all that heat too.

My 455 Tornado power-plant. Still not 100% sure what year it is.

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New Flex-a-Lite radiator and fan installed. (Taken in 2014)
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Mocking up a doghouse, that I built, in front of the radiator to keep the engine heat away from passing through the radiator. (Done in 2014)
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Otto Skorzeny
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby Otto Skorzeny » Tue Feb 18, 2020 9:25 am

The two HP ratings are for the standard Toronado engine and the W-30 option which was higher performance. You probably don't have the car that the engine came from otherwise we could look on the build plate on the firewall.

Again, though, does your guy want the hp rating to the wheel or the hp of a naked engine running on an engine stand?

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Otto Skorzeny
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby Otto Skorzeny » Tue Feb 18, 2020 9:29 am

What do you know about the particular engine you're using? Did you rebuild it before installing it?

Incorrect timing (vac advance, stretched timing chain, jumped tooth, etc.) could cause the engine to run hot. There could also be clogged oil galleries or water galleries causing overheating issues.

What engine did this camper originally come with?

Since GM used the Toro drive train in its own RVs, I'm not worried that you're overtaxing the unit. I am concerned that being in the back of the vehicle instead of the front may be significantly reducing airflow to the radiator

Are you familiar with Applied GMC? If not, contact Jim and talk to him about your situation. His company restores GMC motor homes and he knows everything there is to know about this engine. He may be able to help you.

https://www.gmcrvparts.com/aboutus.asp

UV520
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby UV520 » Tue Feb 18, 2020 6:35 pm

Otto Skorzeny wrote:Again, though, does your guy want the hp rating to the wheel or the hp of a naked engine running on an engine stand?


The engine HP... That is how the BTUs are calculated...


Otto Skorzeny wrote:What do you know about the particular engine you're using? Did you rebuild it before installing it?

Incorrect timing (vac advance, stretched timing chain, jumped tooth, etc.) could cause the engine to run hot. There could also be clogged oil galleries or water galleries causing overheating issues.

What engine did this camper originally come with?

Since GM used the Toro drive train in its own RVs, I'm not worried that you're overtaxing the unit. I am concerned that being in the back of the vehicle instead of the front may be significantly reducing airflow to the radiator

Are you familiar with Applied GMC? If not, contact Jim and talk to him about your situation. His company restores GMC motor homes and he knows everything there is to know about this engine. He may be able to help you.

https://www.gmcrvparts.com/aboutus.asp


It is a stock 1968 to 1970 Tornado power-plant. My guess is that it is a 69...
I already know, with all the testing, that it's not getting enough cool air flowing through the radiator - because the radiator is in the back.

UV520
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Re: What is the HP rating for a stock 1968 to 70 Toronado 455?

Postby UV520 » Tue Feb 18, 2020 6:37 pm

Anyone know the HP of a stock 68 to 70 Tornado 455? Would I be safe in saying that it is 375 or less?

Thank you..


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