A camping forum for VW bus and camper owners.
NEED SOME MORE HP
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Replies to This Discussion
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Permalink Reply by whc03grady on
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The 914 Type IV engine isn't the right choice for a Bus/camper in any case, so you did good there.
A 1979 Bus with the stock setup should easily keep up with reasonable traffic. Its cruising speed is 75mph, and should be able to top 80 in a pinch. If yours is stock and can't maintain 75mph on a reasonably level road, you might have some fuel injection (hopefully you still have intact fuel injection; putting carbs on a fuelie is a big step backward) issue, or you might be looking at a rebuild.
In any case, a car that can't do what it should be able to do (e.g., go 75mph) has something wrong with it, end of story. You'd be advised to fix it toot sweet, before whatever's wrong with it more or less spectacularly destroys the engine.
What's your compression?
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Permalink Reply by Romy on
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Don't put a 914 engine in - although same on the outside, the compression is too high and you'll burn it up.
Small things to increase power (although not by much):
Tune up (plugs, wires, etc)
Electronic Ignition - Pertronix (or Compufire), unless you have a 79 CA which already has electronic ignition
Aftermarket Exhaust (one not made by empi or bugpack)
Take off the screen/mesh that covers the engine fan - it sucks up power
Check your tire pressure
But, as whc03grady hinted, you may need a rebuild. Are you burning oil? FI or carb? If FI, look at your plugs and see if they're gummed up or not. They should be a light brownish color, if they've got oil and gunk on them, something's wrong. Do a compression check as well.
If you rebuild the engine, upgrade to an aftermarket camshaft and get a better pair of heads. If you want to go all out, a one stop sort of place is Jake Raby (aircooledtechnology.com I think). Jake knows his stuff, but the guy is kind of a jerk. I've built both a Raby engine and a cheaper one with just an upgraded cam. The difference in power between the two is only noticeable at high rpm, so for the cost vs reward, and upgraded cam and a good set of rebuilt heads is more worth it. Don't get me wrong, the Raby engine is great, but for the cost of the heads alone I built up the other engine.
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Romy,
I like everything you said except I have to wonder about the wisdom of removing the fan screen. Any resulting power gain would have to be extremely minimal, and certainly offset by the increased likelihood of sucking leaves etc. into the ductwork. Which is bad.
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I agree that it could be problematic to suck in debris, but realistically, there should not be any sort of debris able to get into your engine compartment, unless you left it there (like I've done). It is piece of mind though.
Mine did not have the screen when I bought it, which made it an easy decision for me :). I looked for one and found all sorts of discussions on thesamba, both for and against. It robs a bit of power and creates higher head temps (less flow) but also will protect crap from getting in there.
I have a cylinder head temp gauge (a digital one which is easier to notice changes on than the VDO one) and noticed immediately the one time I forgot and left a paper towel in the engine compartment which got sucked into the fan and blocked about 1/4 of the fan veins.
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Romy said:
I agree that it could be problematic to suck in debris, but realistically, there should not be any sort of debris able to get into your engine compartment, unless you left it there (like I've done). It is piece of mind though.
Since Autumn is nothing more than a certain span of days on a calendar around your parts, you may very well be right. But for many of the rest of us (including the OP, in New Jersey), it's not merely academic that leaves fall from trees by the ton every year, including onto parked and driving cars.
In any case, pace any discussions on the Samba, I can't imagine how the tiny increase in airflow gained by removing the screen is going to affect cooling more than "just barely", and further, how this will possibly have any noticeable effect on horsepower.
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I have not lived in CA all too long, and my Bus dealt with Chicago winters a few times so I am accustomed to quite a bit more than 'a certain span of days'. Also, you may or may not be aware that there are actually deciduous trees here in CA, which fall off in a similar span of time as they do in the rest of the country.
I also can imagine how it would have an impact, slight as it may be. If the fan is harder to turn because there is more drag due to the screen, then yes, power is being removed. If the screen is in place and leaves or debris cover it, it has the same effect as the paper towel I had stuck to my fan.
Since this is just advice being given to the OP, it's his decision what to do, which is why I pointed out that it's piece of mind to leave it in place, for reasons you've mentioned.
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Permalink Reply by 79 TIm on
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thanks for all the hints .I did a complete tune up in it but I didn't do the electronic points . I still have my FI and the bus does not burn any oil. I don't know the compression on any of the cylinders cause I never checked. The bus runs at 70mph but I never push it to 75mph but that does happen
So let me ask ya's if I go with Pertronix ignition and put a header on it will that help some, and if so what header is good and loud,but not to loud
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79 TIm said:
thanks for all the hints .I did a complete tune up in it but I didn't do the electronic points . I still have my FI and the bus does not burn any oil. I don't know the compression on any of the cylinders cause I never checked. The bus runs at 70mph but I never push it to 75mph but that does happen
So let me ask ya's if I go with Pertronix ignition and put a header on it will that help some, and if so what header is good and loud,but not to loud
I don't understand what you mean by "The bus runs at 70mph but I never push it to 75mph but that does happen". If what you're saying is that it can't get to 75, then all you're doing with electronic points and/or a header and/or anything else is just dressing up a dying engine.
Electronic ignition is probably a good idea even for those of us not looking for more horsepower, though it does have its drawbacks. It's not gonna make the bus act like a Ferrari all of the sudden in any case.
From what I gather, a header however is something that should be considered in concert with other engine enhancements, like camshaft and aspiration modifications. You'd also have to pitch your heat exchangers.
There really are no one-step, bolt-this-thing-on-and-drive-away-happy solutions. No good ones anyway.
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What I mean by, The bus runs at 70mph but I never push it to 75mph but that does happen is I cruise at 70mph but sometimes (like going down a hill) it hits 75mph . I don't push it or cruise at 75mph . Does that help or even make better sense.
No way am i going to get rid of my heat exchangers I live north east and what little heat I had was helpful. So no header, I can deal with that but I do need a new exhaust , should I stay stock and should I keep or get rid of the catalytic convert or keep the cat. ?
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You'll rarely hear much argument from me about keeping things stock. That includes the exhaust.
The trouble I (and I suspect most enthusiasts) have is the difficulty of seeing the engine system holistically, like the guy who's been wrenching on them professionally for forty years can. There is very little you can do that won't have some effect somewhere else, an effect that needs to be addressed as well. Since I'm not even close to a real mechanic, I like to keep things as stock as possible as it eliminates the variables introduced by employing non-stock parts. Unless you're a very competent mechanic (if not an engine builder), or can consult with one regularly, I fervently suggest you do the same.
Now what I mean by "stock" maybe isn't what's usually meant by "stock". The engine I'll (hopefully) be installing in my '74 soon is a 2-liter built (not by me) from a 1976-77 case. Obviously this isn't the stock setup for a '74 Bus. But it is a stock 2.0L. Since it's an engine that basically would've come from Germany set up this way, I consider it a stock engine--it's just going to be in the 'wrong' vehicle.
But messing around with aspiration (bigger/more carbs), exhausts and headers, popping in a different cam, that's all stuff that needs to take the whole engine into account. (All this assumes you want to keep the bus forever, incidentally. If you just want something to enjoy for a few seasons, then by all means bolt on whatever random assortment of aftermarket parts you've been told will give it more power and be on your merry way.)
The catalytic converter, that's a different story. Like the air pump they put on Buses for a couple years, it was an afterthought slapped on to appease US regulations, not something carefully designed to make the car work any better. It robs some power (I have no idea how much). I don't know NJ's regulations, but it could very well be illegal for you to take it off. I can tell you that for myself, as a resident of a state that doesn't care, I'd yank it out in a heartbeat (if my bus had one) and wouldn't even shed a tear doing it.
What I'm all pendantically and long-windedly trying to say is that: if your bus can't go 78mph like it should be able to, there's something wrong with it; and if 78mph is too slow for you anyway, then choose your next step very wisely. Romy's comments about the Jake Raby (and his famous Camper Special) are dead-on.
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Haha, grady just posted about 50 seconds before me, so this may read a little weird, but whatever....
As grady said, exhaust is something that helps with other enhancements. However, your engine will perform up to the weakest link in your system. If you have a clogged cat or muffler, this will create excessive back pressure which causes your engine to work harder and reduces power.
I'm aware of three options for exhaust that do not require you to remove your heat exchangers. I'll list them in order of price. Note that all will only work if you have your original 79 style heads (square port) or 72-74 heat exchangers. One other thing to ask - do you have a 79 CA or a 79 federal bus? If your heat exchangers look the same on both sides, it's a federal bus. If they look different, and your catalytic converter is tucked up under a head, you have a 79 CA and would have to change the drivers side heater box to a 79 federal in order to use any aftermarket exhaust.
The first is Tangerine Racing - http://www.tangerineracing.com/Type4ExhaustHeaders.htm . Expensive at $550+, but it's a bolt on and go option.
The next requires you to make your own modifications, so is not bolt on, but is mid range pricey. If you get a Bursch exhaust (for a 1.7L or 1.8L Porsche 914 - see http://www.burschexhaust.com/4cylinder.htm) then flips the flanges (cut off, turn over, and reweld on) and extend the pipe a little, it should fit. This is the route I'm going because Bursch exhausts are easier to find used, I already have one, and I don't mind a little work. Obviously this is more labor intensive, but these headers can be found for ~$100 used, vs almost $600 for the Tangerine one.
The last is the Thunderbird - http://www.aircooledtechnology.com/store/product.php?productid=1686.... This exhaust was copied (horribly) by bugpack and empi. This one works ok, but it's not great. It's a good option if you can't find an original exhaust system, (ex: you have a 79 fed and you don't have the crossover pipe because no one make them and they are impossible to find), and don't want to spend the cash/time for the above options. This is what I currently have on my bus.
Honestly I think you should not be worried about swapping exhausts. Take some time and get to know the layout of the engine, make sure everything works correctly. If you engine is on the way out or has other issues, throwing money into an exhaust system isn't going to solve any problems.
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Romy said:
Honestly I think you should not be worried about swapping exhausts. Take some time and get to know the layout of the engine, make sure everything works correctly. If you engine is on the way out or has other issues, throwing money into an exhaust system isn't going to solve any problems.
Said much more elegantly in 52 words than what I was trying to say in 436.
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