Which carb? 87 Motorhome with 460

[Steve Hartman]

I recently purchased a motorhome Class C 26' that has a 460 and a 650
Holley. Supposed to be an efficient economizer, but the truth is this carb
runs really ragged. Further, I'm not so interested in economy that I wish
to risk performance if I need it.

So....for you experts out there, I'd appreciate some feedback on what it
"should" have on it. Of course, it would be nice to know what the stock
carb for this motor was at the time as well.

Thank you, Steve in Montana

[PeterD]

Steve, define 'runs really ragged'... <g>

IMHO, a 650 may be too small for a 460 engine, though that may be a
personal opinion only. You may find it does better with a 900 cfm carb
(whether Holley or not doesn't really matter, does it?) or even a carb
that is slighter larger than that.

But that assumes you are suffering from lack of torque, if the 'rough'
is low end (idle/and low RPMs) then it may be something else.

[Ashton Crusher]

On Tue, 26 May 2009 23:37:48 -0600, "Steve Hartman"
<dumb...@sbcglobal.netcom> wrote:

I'm against holley's, just too many problems. See if there is an
Edlebrock that's listed for it. They seem to work much better IMHO.

[Kevin]

Ashton Crusher <de...@moore.net> wrote in
news:ut4r15pdkq9343rb2...@4ax.com:

>
>

I have never seen a edelbrock run worth a shit on a 460. It would have come
stock with a 600 vaccume sec. holley. If it is running rough it probly has
a intake manifold gasket leaking, a very common problem, fairly easy to
replace. KB

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[Steve Hartman]

Thank you all, and Kevin. When you say intake manifold gasker, are we
talking manifold to block or carb to manifold?

I just pulled the cover on the engine (E-350) and see that the entire engine
is really clean. However, I didn't notice a kickdown rod. Does this engine
have one or use one? I ask because my performance really deteriorates when
my engine lugs in DRIVE and I got to give it gas and it does not downshift
automatically. I have to manually shift to second.

Steve in Montana

"Kevin" <kevyN...@netins.net> wrote in message
news:Xns9C18AD7284614k...@167.142.225.136...

[Kevin]

"Steve Hartman" <dumb...@sbcglobal.netcom> wrote in
news:H2lTl.16481$jZ1....@flpi144.ffdc.sbc.com:

Yes you should have a kick down rod. and the gasket between the
manifold and the heads is the one that leaks. You have to pull the
intake manifold off to replace it. It is a sandwitch gasket that is well
known for leaking. the spray test should tell you for sure. it is
charaterized by a rough idle but runs fine down the road. KB

[Steve Hartman]

My engine idles fine. It runs crummy. But then, it only runs crummy when
it's under load. I really think it's the carb. I think it's a 650 spread
bore. It also has an electric choke which apparently doesn't work. I also
noticed that the carb bolts directly to the manifold. There is no plate, no
valve, no smog on the vehicle at all. Then again, it IS Montana.....

"Kevin" <kevyN...@netins.net> wrote in message

news:Xns9C195D9C8C04Ak...@167.142.225.136...

[Nate Nagel]

if your motorhome is big enough it may be considered a "medium duty
truck" meaning "light truck" emissions requirements may not apply.

nate

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replace "roosters" with "cox" to reply.
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[nothermark]

On Sat, 30 May 2009 22:03:19 -0600, "Steve Hartman"
<dumb...@sbcglobal.netcom> wrote:

>My engine idles fine. It runs crummy. But then, it only runs crummy when
>it's under load. I really think it's the carb. I think it's a 650 spread
>bore. It also has an electric choke which apparently doesn't work. I also
>noticed that the carb bolts directly to the manifold. There is no plate, no
>valve, no smog on the vehicle at all. Then again, it IS Montana.....
>

Sounds like somebody "fixed" it. Maybe you need to put it back to the
stock configuration before you do anything else. If you can really
skip smog testing issues check out non stock racing setups if you
don't want to go stock. The problem often is folks rip out the smog
mods without understanding what they are screwing up. The engine is
tuned to have them in.

[Kevin]

nothermark <nothe...@not.here> wrote in
news:03a62551aoq2olcl6...@4ax.com:

> On Sat, 30 May 2009 22:03:19 -0600, "Steve Hartman"
> <dumb...@sbcglobal.netcom> wrote:
>
>>My engine idles fine. It runs crummy. But then, it only runs crummy
>>when it's under load. I really think it's the carb. I think it's a
>>650 spread bore. It also has an electric choke which apparently
>>doesn't work. I also noticed that the carb bolts directly to the
>>manifold. There is no plate, no valve, no smog on the vehicle at all.
>> Then again, it IS Montana.....
>>
>
> Sounds like somebody "fixed" it. Maybe you need to put it back to the
> stock configuration before you do anything else. If you can really
> skip smog testing issues check out non stock racing setups if you
> don't want to go stock. The problem often is folks rip out the smog
> mods without understanding what they are screwing up. The engine is
> tuned to have them in.

In 87 the pkups had pretty much "stuck on" emissions stuff. If you
really want to wake it up advance the cam timming 4 degrees. KB