440 motorhome build- 30 degree intake seat?

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HiPer Express
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Re: 440 motorhome build- 30 degree intake seat?

Post by HiPer Express »

Mike Godboldt was talking something about lift% of valve diameter vs seat angle, higher percentage = steeper angle. So 30 degree might be best for very low lift ? And flat diesel heads because even 21st century design 4 valve diesel heads use 30 degree.
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Re: 440 motorhome build- 30 degree intake seat?

Post by mgoblue9798 »

CamKing wrote: Mon Jan 10, 2022 11:54 am
mgoblue9798 wrote: Mon Jan 10, 2022 11:42 am
Thank you for chiming in Mike. Have you had customers run your RV cam with a 413 or 413 heads? About what rpm would max torque be with your cam?
I'm not sure about those heads, I would have to check with my customers.
From memory, I think peak torque is right above 3,000 rpm.
One more question- with 9 to 1 compression, flat top piston level with deck, .039 quench, closed chamber heads and sodium exh valves would you anticipate any problems running 87 octane?
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Re: 440 motorhome build- 30 degree intake seat?

Post by agertz1 »

Durability: Three possible items, Water vapor injection at critical peak pressure/temps. Oil cooler ? Use a forged crank ! Many motorhome engines
were not.
Good Luck, Art.
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Re: 440 motorhome build- 30 degree intake seat?

Post by CamKing »

mgoblue9798 wrote: Mon Jan 10, 2022 12:59 pm
One more question- with 9 to 1 compression, flat top piston level with deck, .039 quench, closed chamber heads and sodium exh valves would you anticipate any problems running 87 octane?
With the right intake centerline, it will be fine.
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Re: 440 motorhome build- 30 degree intake seat?

Post by mgoblue9798 »

agertz1 wrote: Mon Jan 10, 2022 1:45 pm Durability: Three possible items, Water vapor injection at critical peak pressure/temps. Oil cooler ? Use a forged crank ! Many motorhome engines
were not.
Good Luck, Art.
Thank you sir. All those pieces and a good heavy duty trans cooler will be installed.
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Re: 440 motorhome build- 30 degree intake seat?

Post by mt-engines »

HiPer Express wrote: Mon Jan 10, 2022 12:03 pm Mike Godboldt was talking something about lift% of valve diameter vs seat angle, higher percentage = steeper angle. So 30 degree might be best for very low lift ? And flat diesel heads because even 21st century design 4 valve diesel heads use 30 degree.
People do their best to overcomplicate something.

If you have to reinvent the wheel to make 1.0hp/cu in find another hobby.
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Re: 440 motorhome build- 30 degree intake seat?

Post by HiPer Express »

mt-engines wrote: Mon Jan 10, 2022 9:44 pm
HiPer Express wrote: Mon Jan 10, 2022 12:03 pm Mike Godboldt was talking something about lift% of valve diameter vs seat angle, higher percentage = steeper angle. So 30 degree might be best for very low lift ? And flat diesel heads because even 21st century design 4 valve diesel heads use 30 degree.
People do their best to overcomplicate something.

If you have to reinvent the wheel to make 1.0hp/cu in find another hobby.
Sorry, it was Billy Godbolt , from Compcams. Sounds legit, lift under 20% of valve diameter, use 30 degree seat, 20-40% use 45 degree or something between, over 40% 50 degree and close to 50% 55 degree.
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Re: 440 motorhome build- 30 degree intake seat?

Post by mag2555 »

Surly this is not the whole story with these seat to lift recommendations posted above!

They have to be tempered with looking at how efficient the level of port air flow stays in relation to its minimum port area
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Re: 440 motorhome build- 30 degree intake seat?

Post by Walter R. Malik »

Mummert wrote: Mon Jan 10, 2022 2:01 am Adding low lift flow to a head will act very much like adding low lift duration to the cam. If you think the seat duration on the camshaft is too small flatten the seat angle. If you think the cam has to much duration at the seat steepen the valve angle up.

Exactly ... a 30 degree seating angle can take some advantage of using an aggressive, small flat tappet camshaft.
It is all a combination to get where you want to be.
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Re: 440 motorhome build- 30 degree intake seat?

Post by 408swinger »

Whatever the outcome please let us know how it performs . I plan on building up the 440 in my 78 Fireball C-Class and am trying to learn how to accomplish optimal torque / rpms / heat dissapation / mpg etc . ( without going deisel)...

Should I stroke it ? What cam ? Alloy Heads ? Compression ratio ? Oiling mods ? Cooling mods ?
Will it run on 87 ?

This all makes building a WFO drag motor look like childs play ! Lol
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Re: 440 motorhome build- 30 degree intake seat?

Post by mgoblue9798 »

408swinger wrote: Wed Jan 12, 2022 2:32 pm Whatever the outcome please let us know how it performs . I plan on building up the 440 in my 78 Fireball C-Class and am trying to learn how to accomplish optimal torque / rpms / heat dissapation / mpg etc . ( without going deisel)...

Should I stroke it ? What cam ? Alloy Heads ? Compression ratio ? Oiling mods ? Cooling mods ?
Will it run on 87 ?

This all makes building a WFO drag motor look like childs play ! Lol
Yeah there are a lot of recipes out there for strip and street motors, but RV stuff not so much. My original thought was to keep it a 413, but the less than 7 to1 factory compression ratio aint gonna cut it and pistons are high as giraffe's balls for them. 440 will make 500ftlbs easy with cam, compression, and headers. Keeping mine at 9 to 1 actual measured compression to run cheap gas. With you on the diesel as this is a front engine rig I don't want to listen to it for hours on end.

I will have dual gas tanks, one with non ethanol 90 octane to run the generator. I can switch feeds if needed to get out of trouble with the 87 pulling in the mountains. Also plan to run MSD with a timing retard dial. Spray mist bar across the front of the radiator if needed.

Camking (Mike Jones) has the best off the shelf grind for a big block Chrysler for an RV. Short duration with modern faster lift profile and most area under the curve by a long shot for a 202@ .050 cam. Shooting for at least 8mpg as a target for mine pulling a toad truck and small boat combo behind it.

As far as heat goes with Mike's cam, 9 to 1 with quench, and headers engine temps will be way down. Guy on here that goes by the handle Wyrmrider has some good info in his posts about big block mopar stuff.

If I find the 413 heads strangle my 440 too much, then it is just a matter of bolting on a set of stealth heads with good valves. Would like to save that money and spend it elsewhere on the rig though. Same thought for the stroker kit in my mind. If you do stroke it how much do you gain without spending more on a set of good heads as well. Same slippery slope spending problem we have will all our projects.

I am sorting through the rig at the moment getting it back road worthy as it sat for a while before I got it. I'll get a baseline with the 413 727 combo currently installed now for fuel mileage, rpms, etc before pulling it for the 440 and probably 518 trans.

I'll post my results as I gather them.
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Re: 440 motorhome build- 30 degree intake seat?

Post by HDBD »

This is a highly loaded industrial engine essentially. Me personally I would use a wide 45 deg seat and stop dwelling on nuances that can be addressed with the proper cam choice.
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Re: 440 motorhome build- 30 degree intake seat?

Post by agertz1 »

If you want torque... I just happen to have, (2) new 4.5" cranks. One is Molnar, 8 bolt and one is 440 Source?/ 6 bolt. I will never need them.
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Re: 440 motorhome build- 30 degree intake seat?

Post by 408swinger »

agertz1 wrote: Wed Jan 19, 2022 7:04 pm If you want torque... I just happen to have, (2) new 4.5" cranks. One is Molnar, 8 bolt and one is 440 Source?/ 6 bolt. I will never need them.
Art.
How would that long stroke work in a heavy load /high heat application that might run for 8hrs constant ? What would be the pitfalls?
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Re: 440 motorhome build- 30 degree intake seat?

Post by piston guy »

Air doesn't like to turn so it makes complete sense than the 45* angle would flow more air as the valve gets "out of the way" of air flow. Race engines use 55* seats for more flow yet. Changing a 428 Ford CJ to 45 intake valve/seat was worth 12 hp by itself for me. The trouble with a flow bench is the valve is not in motion like it is in the engine and you also can't simulate piston induced reversion because of that.
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