Uphill speed with Chevy 5.7L V8

[machias]

Hi all,

This is my first post but I've been lurking and searching around for answers for a while. I truly appreciate everyone contributing and sharing what they know. It's been very helpful.

This past summer we bought a 1988 420RG Minnie Winnie. We've taken it out 3 times and are going down the Oregon coast this coming week.

I've searched around here and elsewhere, and discussions about increasing HP come up a lot for RVs with 350 small blocks. I learned to drive in an '83 Malibu and remember that had terrible power so I guess I shouldn't be surprised. Regardless, I'd like to know if others with an ~10,000lb GVWR rig top out at 35 mph going up a steep hill or mountain, or is something potentially wrong with my powertrain? And to get to 35 mph I'm dropping into 2nd and have the pedal buried. On a level highway I can get up to and maintain freeway speeds, so inclines are my only concern.

The reason I'm worried is because the previous owner said he blew the engine coming cross-country and had it rebuilt. I'm trying to figure out if I'm in for a surprise when I take it in, or is what I'm experiencing "normal"?

The previous owner called this rig "The Slow & Steady", so I'm optimistic there's likely nothing wrong with the engine and I can limit my immediate repairs to the fridge & grey plastic.

[EldoradoBill]

I had a low mileage 85 class B Starcraft conversion with 305 in top shape and 3 speed transmission. It was slow and with 4 people and gear on board you were better off just staying right with the flashers on. I think the nickname of your much heavier rig says it all....

[beaverman]

If your running a SB Chevy with stock exhaust and all the pollution crap on it, that's normal pulling steeper grades ; word of warning, don't bury your foot in it for a long period of time and wind it out, that's probably what blew the original motor, take your time and enjoy the ride, you'll get there eventually.

[machias]

...don't bury your foot in it for a long period of time and wind it out, that's probably what blew the original motor....

That's an excellent point. The previous owner brought it to the Pacific Northwest from Maine and likely didn't have any experience driving it through mountain ranges. Adding a tach just went on my to-do list.

Thanks to both of you for confirming.

[tiinytina]

Fully loaded stop at a truck scale and find out your front and rear axle weights... you may be more loaded than you thought. Only ride with enough FW for travel needs and empty GW and BW tanks before departing 8lb per gallon of water, adds up fast....   and yes.. life in the right lane flashers on vs blowing an engine...  enjoy the ride as well as the destination.... 

[CapnDirk]

Say Machias:  What part of the northwest are you in?  And welcome!

[Froggy1936]

I have a 77 Mini Winnie I run at a little more than maximum 11500 lbs With A (95  5.7 TBI 4L80E w headers ) I never run it up over 4500 RPM I have been down to 2nd gear on some very steep long hills that i could not get a run at But that is an unusual situation! My final deduction is always go with a big block if you are going to run heavy The difference in MPG is very little as the small block has to work a lot harder ! Frank 

[machias]

What part of the northwest are you in? 

Mill Creek so just north of Seattle.

[tmsnyder]

Is 'Slow and Steady' still rolling?   


That 350 is probably only 190hp from factory, almost 30 years ago, so it may not still be putting out all those ponies.


12,000lb, going up a 6% grade at 35mph = 67hp if I did the math right.  That's not counting the wind resistance, and all the losses before the power gets to the wheels.