Do I need Heat risers in Southern California?

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Momboy007
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Joined: Fri Apr 01, 2016 6:56 pm

Do I need Heat risers in Southern California?

Post by Momboy007 »

Hello All,
I continue to work on my little buggy and have been reading concerning the Heat risers for the exhaust. Do I need them in Southern California? My headers do not support them if I need them.
I am running a EMPI 3031 Pict 1 and just can't seem to get it tuned correctly. I have checked the valves, timing, oh yea and I have a breakerless dizzy.

Any advice would be greatly appreciated

Rick
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jsturtlebuggy
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Re: Do I need Heat risers in Southern California?

Post by jsturtlebuggy »

From what I getting from your other posts that you using the buggy at Big Bear, which is high altitude and yes you may need heat to the carb to keep it from icing up.
Any idea of what jetting is in the carb?
How is the distributor timing? What setting at idle?, and what is timing at full advance?
Just installing a new carb without first checking it out and knowing what jets are in it can cause problems with it running correctly.
Do you have any idea of what the cylinders compression is? and has engine ever had a leakdown test done to see what shape engine condition is?
Joseph
Manx Club #1095
Having fun with Buggies since 1970
Worked in VWs in shops since 1970
lastmanx
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Re: Do I need Heat risers in Southern California?

Post by lastmanx »

I don't use heat risers and I live in Massachusetts but I stop driving by November. its to cold for me. what carb air filter are you using? it makes a difference. those short chrome ones can effect it. look at the stock vw oil bath filter and notice it has a 3 inch stack inside that creates a sort of fog cloud of air fuel above carb that makes it run. I add a 3 inch piece to extend those short filters. I understand you may not have body clearance : which is why they were invented. look at a early stock bus or karman ghia they used a vw piece at a 90 degree angle to compensate for height restriction. or your answer could be like above answer suggests;jetting. if you have no air filter at all, that is the problem. hey aren't custom cars fun! don't give up you'll figure it out .keep smiling.
Momboy007
Posts: 78
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Re: Do I need Heat risers in Southern California?

Post by Momboy007 »

Hello All,
My Buggy has a 3 inch body lift, so I do have room for a 4 inch riser without issue on my Buggy, It is using a spun aluminum air filter with a paper element located inside. I do not drive this buggy in the cold, it has always (since I bought the vehicle from Turn Key Manx earlier this Year, never been below 72 degrees outside.
I did pull the carburetor that was sold with the car, a 34 Pict 3, and installed the less complex EMPI30/31 Pict 1, thinking the problem would go away, still there. I know for a fact the motor is fresh and has less than 6K miles on it since being completely rebuilt. I will find out what jetting is in it next time I go to Big Bear
Thanks again for all your help,

Rick
lastmanx
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Re: Do I need Heat risers in Southern California?

Post by lastmanx »

does the filter stand off by a 3 or 4 inch tube? try that if not. and exactly what is the issue that made you change carb
Momboy007
Posts: 78
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Re: Do I need Heat risers in Southern California?

Post by Momboy007 »

LastManx,

I do have a 4 inch pipe between the top of the carb and the filter, but no exhaust risers.
YOU are the reason I changed carbs!!!!, I had a 34 Pic 3 and it ran like Poop!!, so I changed it mostly on your recommendation


Rick
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5150bossman
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Location: So Cal

Re: Do I need Heat risers in Southern California?

Post by 5150bossman »

Do you "need" heat risers? Short answer is no. Will they help your buggy run better? Maybe. As it was once explained to me, If you are running a single carb, the manifold runners are much longer than the ones for dual carbs. As such, on the longer runs for the single carb, the fuel that is atomized and going to the combustion chamber tends to re-condense into little droplets that are harder to ignite than properly atomized fuel. The heat from the heat riser transfers the heat to the atomized fuel and helps keep it atomized making it easier to burn. This is an added benefit over just keeping the carb from icing up.
lastmanx
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Re: Do I need Heat risers in Southern California?

Post by lastmanx »

changing the carb was a good move. sorry I can't remember your exact issue. are you saying that the engine is the same running like poop? you can fine tune the carb using the adjustment screws, which is sometimes necessary with different exhaust (not stock). forget heat riser, most risers rust on the inside becoming clogged and therefore don't
work correctly anyhow. stop comparing your buggy to a stock beetle because it is not stock. if it still runs like poop your issue is not the carb, and you need to look elsewhere. cross the carb off the list and move on to finding the real problem. are your vacuum lines connected properly or blocked properly? is the auto choke adjusted correctly or eliminated? I prefer to eliminate it. is the idle circuit connected or bad ? I have had them just up and quit so I now carry 2 spares. my original advice to change the carb to a better one is solid advice. saying it runs like poop is not very specific. clogged fuel pump, gas filters. and lines, rust in tank can all create issues associated thinking it is carb. I only try to give advice that I know for sure with personal experience will work. when I purchase a buggy running or not I go through absolutely every thing. it takes an great deal of time, but I do it. i'm not saying you have to. my first few buggys I waited until they broke down on the side of the road until I fixed them. I am now 55 years old and have grown out of that habit. perhaps you should just change every part until you get it right it works for some people, but not always.
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jsturtlebuggy
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Re: Do I need Heat risers in Southern California?

Post by jsturtlebuggy »

Going back to your original post in another person thread, It appears you biggest problem you had then was a hesitation with the 34PICT carb and 009 style distributor. Is this correct?
I used all kinds of Solex carburators over the last 40plus years. From 28PCI to PII-40 dual throats.
I have used, adjusted, rejetted, adjusted accelerator pump circuit, and played with 34PICT carbs for many of these years.
The biggest problem with a 34PICT carb is with trying to use it with a full centrifugal such as a 009 is the hesitation problem you were having.
Yes you can help the problem with the hesitation by richening up the carb. This is accomplished by making the jets in the idle circuit bigger at the expense of using more fuel.
Yes I used 34PICT in the dirt and sand without problems for many years now. Originally none of the Solex carbs used on VWs came with any kind of bushing for the throttle shaft. When VW started have to use emission controls then a bushing was use on throttle shaft only on the side where throttle arm is. Other side of carb where accelerator pump linkage attaches never had a bushing.
The reason for this bushing on the one side was because of second linkage arm to hold throttle plate one for a few second on deceleration.
Yes the carb body wears where throttle shaft rides and can have bushing installed.

If your throttle shaft fits tight (or even has a little slop) in carb body in your 34PICT carb it is still usable and will give more power then a 30 or 31 PICT carb ever will.
I posted before that with a 34PICT carb you really need a distributor that has both Vacuum and Centrifugal advance in it. This was the way the carb was design to function.

Have you ever had a compression check done on the engine? How about a leak down test to see if leaking by rings, valves, or even between cylinders and heads?
These two test should perform to see if engine is in good mechanical condition before you start trying fix anything.
As for heat risers they serve a function in and enclose engine compartment with stock muffler, they do not work well with aftermarket exhaust systems. Sometimes you need to add heat to intake system. Intake manifolds can ice up not only on outside, but inside as well and stop the engine from running. VW ducted air from under the cylinders to the air cleaner to help solve this problem. It doe not have to be that cold to have it happen. A low dew point, high humidity in cold air, will cause the freezing.

If you do not have the experience or time to read all that has been written about what is happening with your buggy in places such as The Samba.com, then you need to take it to someone that know how to work on VWs that can solve you problems you are having.
Joseph
Manx Club #1095
Having fun with Buggies since 1970
Worked in VWs in shops since 1970
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jsturtlebuggy
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Re: Do I need Heat risers in Southern California?

Post by jsturtlebuggy »

Over on Shop Talk Forums.com in the type 1 forum, titled My Weber Experiment.
There is a person that is going to find out if using motorcycle handlebar grips heater pads will work on keeping the manifold from icing up.
He has posted picture of what he is doing. It looks very interesting on what he going to try. Hopefully it works out well and can become a solution for other having the same icing on their intake manifolds.
Joseph
Manx Club #1095
Having fun with Buggies since 1970
Worked in VWs in shops since 1970
andygere
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Location: Santa Cruz, CA

Re: Do I need Heat risers in Southern California?

Post by andygere »

I'm running a stock 1600 DP, 34 PICT 3, SVDA distributor and a Manx header and no heat risers. What I have found is that it takes a long time for the motor (and therefore the manifold runners) to get warm. The buggy studders and hesitates a bit until I see the needle on the oil temp gauge start to move. It runs much better after that, giving good power and smooth acceleration. I spent a lot of time getting this carb set up, and found that the suggested initial settings for the bypass screw were off by several turns. Go through the setup procedure step by step, but only after the engine is really warm. I found that just idling it wasn't adequate to get it warm, I had to drive it. I do think that the manifold heat helps atomize fuel when the motor is relatively cool, but you can make it run fairly well without it. I never drive anywhere cold enough for carb icing to be a problem, so that's off my radar screen. Do be sure your valves are adjusted to spec before tuning the carb or timing the motor. I discovered that this makes a big difference.

My engine is tired, and while compression is decent, I suspect a leakdown test would reveal some ring or valve wear. I did rebuild the Bocar 34-Pict that was on the buggy when I bought it, and it had a good, tight throttle shaft bushing. I never was able to get that carb to give me a good idle, and ended up buying a new EMPI 34-Pict 3. [I suspect I just didn't go far enough with the bypass screw, and didn't get the motor warm enough before tuning] The Empi 34-Pict 3 is a surprisingly well-made carburetor, with some nice advantages over the Bocar. The fuel inlet barb is threaded into the carb body, not pressed, which is a real safety improvement over stock. In addition, the accelerator pump linkage is modified so the carb will fit on an alternator equipped motor without grinding the alt or using a spacer under the carb. Too bad the PO of my Manxter took a grinder to the alt case... The Empi carb also comes with a second set of jets, and I may move up to the larger main jet to see if more fuel helps with cold motor performance. Note that the 34 Picts are very sensitive to fouling in the tiny idle jet, and if you just can't get it to run right, take that jet out and very carefully clean it (don't ream it with wire, etc.). I run 2 fuel filters, and a month or so after getting the carb set up pretty good, it suddenly started to stall at stop lights. I removed the idle jet, cleaned it with carb cleaner and compressed air and the problem was solved. I think that the 34 is the smallest carb I'd want on this motor, I feel like when it's running right, it has more potential that's only limited by the small carb and long manifolds. An even smaller carb would choke it, further limiting performance. I'd give the 34-3 another chance, paired with an SVDA they work pretty well.
lastmanx
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Re: Do I need Heat risers in Southern California?

Post by lastmanx »

hey andygere not sure if you are asking if you need heat risers, but if your exhaust doesn't have the hookup in it then you can't use that exhaust ; you would have to change to one that has the connections. as you can see some people want heat risers some don't. that's why some exhaust use them some exhaust don't. they are both correct. personal preference. one school of thought says exhaust with the connection messes with smooth exit of gases. the other school says the warming of the manifold out weighs the flow issue. and warming up your engine before you drive is good also.
andygere
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Re: Do I need Heat risers in Southern California?

Post by andygere »

No, not thinking of adding heat to this motor/intake, just acknowledging that I think they really help get the most out of a DP1600/34 Pict 3 motor. My previous buggy had heat risers tied to the dual cannon exhausts, and as much as those exhausts are maligned, it ran quite smooth and warmed up quickly, even with an 009 dizzy. Once I learned to work around the flat spot, it was a fun and consistent ride. The non-heat riser motor in my current buggy takes forever to get warm and settle down.

Most buggy motors I see don't have thermostats and the associated engine tin. Would that system help get a buggy motor warm, or does it only really work with the full tin system and enclosed motor on a beetle?
lastmanx
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Re: Do I need Heat risers in Southern California?

Post by lastmanx »

the thermostat and flaps do warm the engine quicker. they were designed for that purpose; along with directing the air to the heat exchangers of the exhaust to then heat the interior of a beetle. with a buggy body you don't have the heat channels that are built into the rockers of a beetle; so you don't need the redirection of fan air. you do lose the benefit of quick warm up. also most buggys are not used in cold conditions (original intent). mostly summertime use. THE BENIFIT of not using the thermostat system and blocking or removing the housing vents to the heat exchangers is to always have all available cooling air directed to the motor. (no benefit of quick warm up). IN THE RUST BELT areas of USA of which I live; the thermostat system rusts and is prone to failure and malfunction. have you ever driven your beetle in 0 degree weather for months? well the donor beetle used to construct a buggy in these areas has. imagine the thermostat flaps rusted shut with zero cooling air getting to the motor. so it gets removed.(it was not working for us anyway) if you were to subject your buggy to harsh of road driving the delicate thermostat system could malfunction.(since your buggy has no heater channels you only have it for quick warm up) you remove it for peace of mind that it won't malfunction if not there. QUICK WARM UP is relative. yes it takes a little longer to warm up. A LITTLE I don't mind. when I use my buggy I like spending time in it. so if longer warm up means longer time in my buggy I don't mind. I plan accordingly. I have removed the thermostat system in every buggy I have built. they all take longer to warm up. in cooler weather they run below optimum temp I will assume. I don't have temp gage but I can feel the difference in performance. I HAVE NEVER OVERHEATED a motor without the thermostat system. I also don't use my buggy past the month of October. i'm only restating the facts of science that have been written in books for centuries. by all means if you have a perfect working correctly thermostat system use it! again different strokes for different folks. none of this info is new just new to you. keep learning and keep smiling. see you in the sand.... oh next April that is I winter stored my buggy already :( :( :wink: :lol: :lol:
andygere
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Location: Santa Cruz, CA

Re: Do I need Heat risers in Southern California?

Post by andygere »

lastmanx, thanks for the info. Where I live I'm more likely to overheat, and will simply live with a longer warm up time. I'm planning a motor build for this winter, and will go to dual carbs so the manifold heat will become a moot point for me.
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