RV Cams?

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I tend to agree with guys that say it's sort of a package deal. But there may still be a way to bump up power economically.

Your truck should have HEI ignition. One thing to try first would be to find a spring kit for ignition advance and allow the ignition to advance a little faster right off. Lousy for emissions, good for snap. The total high RPM advance should remain close to the same, but with the right springs it can come in earlier than the smog curve that it has now. This won't help much on a high speed hill, but the truck will run better in town stop-and-go and other lower RPM's.

At 80K you might find an earlier set of used higher compression heads, give them a valve job, regain lost performance and bump up compression at the same time. (As an alternative, there used to be some new cast iron heads that sold for a little over $300 a pair, but I suppose those days are gone.) Bumping compression ratio will depend on how the smog engineers robbed it though. If the pistons are dished, the earlier head chambers won't be much less volume. But if the pistons are fairly flat-topped, the earlier, closed chamber heads may bump up the compression quite well. Maybe up to 9.5:1 would be good for towing, as compression ratio mostly affects torque. As Turtle noted earlier, the intake runners will also be larger. Used early heads should not be too expensive, and it's mostly for regaining the lost pre-smog torque mind you.

I assume it has a Rochester Quadrajet carb, and almost all of them flow 750 feet. I think there were some 850 feet units. This is significantly higher than other carb brands, yet works because the front barrels are small and work well at low speeds. The rear barrels are humongous, but only open at high speed, so the carb does not stumble easy, even at the large total flow. They are also more fuel stingy than other carbs, until the back barrels open anyway. The current jetting is probably a little lean, and if you can enrichen the mix, you will find a lot of power by doing so. There is a richer happy medium, than you have, where both power and fuel economy actually improve before economy goes the other way again.

An RV cam should improve power if you can first bump compression and intake runner volume. But even an old 327 flat tappet cam would an improvement over what you have. If your engine has roller lifters, the cam can be improved a lot. But I don't think 1985 did offer rollers.

If you can get some older heads cheap, the "tow tune" should not cost too much. Revamping the 350 will still allow for better fuel economy than a 454, or even a 383 or 400 smallblock. Yet the power increase can be pretty remarkable.

Good luck in your quest.

Wes
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FishOnOne wrote:
Pull the old engine and drop in a new Chevy crate engine. Don't waste your time and money with a cam swap on an old engine.

Link

I think this is a good idea if the budget is there and the rest of the truck is in good condition. My vote would be for a chevy crate...383 (400 crank in 350 block) tuned for hauling. Think GM used to have an engine like this is their catalogue,

Pull the old engine and drop in a new Chevy crate engine. Don't waste your time and money with a cam swap on an old engine.

Link

I tried many tricks but I never did get anything pull until I bought a 454. now I have a druamax diesel and I love it. pulling a small camper up mountain at 15 or 16 miles an hour is not much fun.

dodge guy wrote:
Yes the RV cam will work as expected! They work great and do improve power and torque. Cam, intake and exhaust will do wonders! An if you really want to upgrade the heads and you will be real happy!

The guy wants 85 to 135 more HP out of a small port low compression smog motor an a cam change "will work as expected"? :h

How does that work? If you can pull that off I need you to come over and tune some of my race engines for me. :E

Bearsfanatic85 wrote:
Down Home, Your kidding right? I mean seriously, all im looking to do is raise the Hp rate from 165 to around 250 to 300 which for a small block chevy really only means headers/dual exhaust, intake and cam. Like I said i dont want a race truck I just would like to be able to stay above 35 going up hill. My question was directed to anyone that may have done something similar and if so what were the specs on the cam.

I could never settle on a little bit. :)
Call the mfg they can fix you up on a cam and headers properly matched to everything else.
However, I don't think you are going to see the result you want. Moving an RV or anything you like torque. It is what twist the universals off.
I think you might be a lot more pleased with a crate RV designated tune motor. GM crates weren't that expensive but... You gotta decid on a budget.

Ron3rd wrote:

Bearsfanatic85 wrote:
The truck only has 80,600 miles on it, But the 350 is only rated at 165 hp

True, it's a dog of a motor. Had the same thing in my 85 C20 Crew Cab. We called it the gutless wonder but only pulled a very small motorcycle trailer with a couple of the old 3 wheel ATCs back in the day. For any serious towing with this era of truck, you need the 454.

The 350 is not a 'dog' of a motor. It's (sbc) the most commonly used performance 'built' engine since the mid 50's.

Just about any mid '80's' engine....including Toyota engine were down in power due to the way emission engineering was managed at the time.

The 350 basic block has a lot of potential to build it into a great powerhouse....depending on the internal and external components selected ...depending on the needs.

Performance parts are generally the most reasonable priced...due to the great demand this engine has from performance minded individuals.

Bearsfanatic85 wrote:
Down Home, Your kidding right? I mean seriously, all im looking to do is raise the Hp rate from 165 to around 250 to 300 which for a small block chevy really only means headers/dual exhaust, intake and cam. Like I said i dont want a race truck I just would like to be able to stay above 35 going up hill. My question was directed to anyone that may have done something similar and if so what were the specs on the cam.

I would call Edelbrock or some other well established performance company and talk with one of their consultant's.

They can suggest cam, headers, carb , intake manifold, etc... that would work for your goals.

I understand you are looking at low and mid range power increase....mostly torque.

A Chevy 350 is a great engine and can be configured for anything from high revving sports racing...to a torquey truck engine for hauling.

You have indicated clearly what your needs are and also are not looking at spending huge bucks. I would think a performance company would be well able to recommend what for the most part, would be add on performance parts (except for the cam which as you know is an internal job)and keep it within your budget. The good thing about a performance consultant...is that if they are good...will advise a matched set of parts...matched to get the power and type of power (ie; power band) you want.

If the new parts are too pricey...then look for similar used parts on the internet.

My suggestion. Other may have better ideas.

Yes the RV cam will work as expected! They work great and do improve power and torque. Cam, intake and exhaust will do wonders! An if you really want to upgrade the heads and you will be real happy!

If you are using the stock timing specs try advancing the timing until it pings on acceleration and then retard it a couple of degrees. Those old smog motors usually can run with a lot more timing.