European Motorworks Headers

[Fillmore77]

Did a search, found 3 topics, 2 of them 5 years old, none answered my questions. So here goes :

PREMISE : I'm planning a rebuild for this winter, my goal is to do a slightly-better-then stock, Will have my heads done by hoffman, ports cleaned by me, and the cam picked by Jake Raby to match the rest of what I put together. This will not be a CS, but I will put the best quality parts I can afford in it. A $1000+ exhaust system I can't afford.

The engine is a 2.0l, running the original L-Jet FI. OE tranny and gear ratios as well.

One thing I want to do, is install a better flowing exhaust, my #1 goal being getting the heat out of the heads. For this I am willing to sacrifice my heat exchangers, that I haven't used for heating since I own the bus anyway.

I want equal length primary headers, was going to design them myself to either connect to or altogether replace the heater boxes. Now I found this : http://www.europeanmotorworks.com/pvw/204-100/type-4-exhaust/72-78+Bus+Heater+Box+Replacement which I would mate to a thunderbird extractor : http://www.pertronix.com/prod/ex/thunderbird/pop/h4001.aspx

So, at last, here are my questions :

1-How much heat dissipation form the exhaust system is acomplished by the heat exchangers. HE surface temps have been measured at 350f, compared to 750f before and after the HE, so should I worry about replacing them with something that will obviously radiate more heat on the engine surface ?

2-If the answer to above is yes, I should worry, would the ceramic coating offered by European Motorworks help reduce this effect ? I've read that ceramic coatings can make a huge difference, but I'm guessing that thickness/quality als plays a role. Need to learn here, please teach me if you know. Am I better off with plain steel ? OR buy them plain and have them coated with another process ?

3-Have anyone ever installed these, or better yet this combination (headers/extractor), and what can you tell me about the results ? Benefits ? Negative issues ? Rants ?

Any comments, information, suggestions or insults welcomed, if I find out this is dumb idea, I'm still better off...

thanks !

P.S. I hope I'm not breaking any forum rules, but for reference, here are images of the parts mentioned above.



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You can have it quickly, you can have it good, you can have it cheap...Pick two...

1977 Bay Westy, stock 2.0l FI, Hailing from Quebec, Canada.

[1977_L63H_P27]

I think heater boxes on a bus are as useful as tits on a boar hog myself. So I would love to go with a simple set-up such as this. My only concern would be the cooling. As the lower tins meet up with the heat exchangers and make sure the cooling air travels completely under every cylinder. With that extractor, all your cooling air would dump near cylinders 1 & 3. You may have to build your own tins, but I like that exhaust system. Good luck!
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[Bajatacoma]

I can't comment on those pipes, but if your heat isn't working it's because you don't have the system adjusted right. Admittedly it's not great in the rear of the bus, but mine will keep the driver and passenger warm and it easily keeps the windshield defrosted once it warms up.
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'78 Westy

Who is the happier man, he who has braved the storm of life and lived or he who has stayed securely on shore and merely existed?
Hunter S Thompson

[SGKent]

I guess I differ. If you want to lose heat, one way is to retard the timing which lowers the HP and the burn will move into the exhaust stack. Right now your exhaust ports were designed to be cooled by the 1972-74 style heater boxes. The air flowing through them and dumping pulls heat off the exhaust ports. There was a thread recently where someone opened up their exhaust, only to find the engine made not only more HP but more heat too. Duh - what a quaint idea - more air, more fuel and more heat. Some of the cars we raced generated so much heat that the hoods had to be repainted after every race. You get less heat by slowing air, which means less HP but it also means less fuel gets burned.
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Steve aka Merlin the Wrench

formerly Steve's Racing and Engine Blueprinting. Wrenching since 1967.

bdamico on GF wrote

[Fillmore77]

Thanks all. I have to stop and think about what SGkent wrote, like I said, I'm not pretending that I will be build something as good as a CS, but I would be lying if I said that's not the direction of travel. The CS combo (and it's all in the combo, I've heard) does generate a LOT more HP and torque, and does require a better flowing exhaust then stock.

Again, I'm not aiming at making a race engine, just a "slightly better then stock" engine, by virtue of spending what money I have wisely and applying what science is out here to be found (or mooched) on the T4.

I know from my readings that equal length primaries and a well calculated merge length are primordial for obtaining a proper scavenge, and that helps pull the hot gases out of the head. I also understand more power means more heat needs to be generated, but I'm kind of hoping that whatever cam recipe Jake will recommend with my purchase will help make the burn more efficient. The last two variables I need to figure out in that formula are the compression ratio, and the timing itself. Some of the improvements Jake builds into the CS are out of my reach, as they are based on years of experimentation and more forgotten knowledge then I will ever acumulate. I'm ok with that. But I'm oping I can still make a positive difference, without making things worse.

Bajatacoma : my heat isn't working because my flaps are seized...and my fan is burnt out. My point is that I don't drive in winter, and I have a BN4 installed for those spring and fall drives where a little heat is required. My bus is a week-end warrior, and I don't use it for long distances, just to go farting around the countryside with familly.

1977_L63H_P27, I don't get from your post :

[Hoody]

Never second guess German engineers, unless your name is Jake or Udo.Wait for Jake's new set up.

[Fillmore77]

[Vince79]

http://www.heatshieldproducts.com/automotive_products.php

[Wildthings]

I would argue against some of what SGKent said. In general the coolest exhaust and head temperatures are going to be found on the most effecient running engines. Tune your engine to get the maximum amount of power out of the same amount of fuel and you should see lower temperatures as more heat is being converted into mechanical energy. No matter how your engine is tuned you still need the same amount of HP to cruise down the road at a given speed. Say 30 hp to drive down at level road at 60 mph. Increase the efficiency and thereby decree the fuel flow and you should see cooler temperatures not hotter ones. In all likelihood an engine getting 15 mpg is going to be running noticeably hotter than one running 22 mpg (and may not pull the hills as well either).

That said if changing the timing from 32° full mechanical advance to 28° full mechanical advance doesn't change the horsepower output significantly then the 28° is going to expel the exhaust gases quicker and give less time for them to transmit heat into the heads.

I really have no idea how much cooler (if any) an engine with heat exchangers is going to run than one without. On engines with the early style exhausts the pipes coming out of the heads are not insulated so they are going to be able to radiate heat just the same as straight pipes, while on the later exhausts the header pipes were originally wrapped and may have kept the radiant heat down a bit. The use of header wrap and how one reshapes the bottom tins would determine how much radiant energy would be radiated back into the heads by the bare pipes. I really doubt that there would be much difference in the amount of heat being conducted by the pipes back into the heads between the use of a shielded and non shielded header pipes, but could be wrong.

I am willing to accept that Jake's test say the heads will run cooler with the heater boxes in place compared to bare pipes, but if I don't know what would happen if you shielded the bare pipes.

[Fillmore77]

Thanks Wildthing, your point about making the potential for HP and actually using more HP generating different levels of heat is a good one. My understanding of how Jake's engines run cooler while providing more power is that they use the available mixture more efficiently.

You are also correct about the exposed header pipes on original systems. Even on later years like my 77, I believe the pipes had double walls only from the U pipe, and the primaries that bolt onto the heads were single wall Stainless steel. Using custom tins to replicate OEM warm air redirection and provide shielding for the engine also sounds like a simple solution.

Vince : Excellent link, thank you, I have used the wrap rolls in Kart racing applicaitons, and while effective, it tends to unravel and loosen in a short period of time. But they have another product I didn't know about, which looks more like sheets you can roll around the pipes, this stuff looks promising.
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You can have it quickly, you can have it good, you can have it cheap...Pick two...

1977 Bay Westy, stock 2.0l FI, Hailing from Quebec, Canada.

[Jeff Geisen]

... that header wrap stuff will cause rust and dramatically shorten the life of your system. It'll soak up water and hold it right against your pipes.

This is the 21st century, ceramic coating is available.
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... I actually drive my bus, and I maintain it myself, it runs fine. I drive it all over the place. Really, check my gallery.

I John 4:20, 21 NKJV

[Fillmore77]

[Hoody]

Have you considered buying some good used flapper boxes, keeping your heater boxes and putting on Jake's version of the thunderbird extractor and muffler?He stated not that long ago that he would be manufacturing this soon.I think he said something in the 400.00 range.Tangerine racing has an extractor muffler set up that Jake was instrumental in designing for around 600.00.Colin set it straight quite some time ago how important the heater boxes were for dumping heat whether you use your heat or not.You should consider joining The Aircooled Technology Forum and posting your question over there on their "exhausted" section.In answer to your question about ceramic coating.No all ceramic coating is not created equal.To do it properly both the insides and outsides of the pieces are coated.First media blasted then coated.Jim at New Image Powdercoating in Struthers Ohio is one of the best in the business.Also check out Jet Hot.Hope this helps.

[Desertbusman]

I don't know what a t-4 exhaust system looks like and have no need to know. With a T-1, J-tubes produce much more radiant heat than HE's. Howard Washington had his info in a HVW mag tech article about how to make J-tube heat deflectors. Real quick, simple and cheap. The bottom line was that with the deflectors he was measuring 7 degree drop in OT versus not having them. The J-tubes really bombbard the head rocker boxes and pushrod tubes with radiant heat.
That reminds me, he's going to jump all over me since I havn't put on my deflectors yet.
But I sure recognize your desire to have equal length runners. The good old buzz word was spaghetti tube headers.
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The best thing that anyone can do for their Bay is get the Volkswagen of America Official Service Manual published by Robert Bentley. Without it the bus is pretty much doomed.

[78Kombi]

I have that exact setup. and have used it for 4 years so far.
I have been on plenty 4 hr drives and up mountains and in 100 degree weather and in traffic. and so far I never have encountered a time when the oil dip stick was too hot to hold. I use a cht now and have not produced temps over 325 yet.
you just gotta block off the air flow at the bottom of the shroud.
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78 hightop 2.0 FI

[Fillmore77]

Hoody : I will check out Jake's website again, but last time I looked, he didin't have anything that would mate to the 75-78 type HEs, with the 3 bolt flanges. Same problem with the thunderbird extractor, they use to have a model 4002 that would have been perfect, but discontinued it for a while. This is why I'm looking for options.

Desertbusman : Biggest diffeence I can see between the t1 and t4 exhausts, and J tubes VS the EMW headers, is that the t1 seems to curve around but stay in line with the heads, while the T4 exhausts, and the EMW headers move laterally away from them, actually in a much better way then my original headers did. MAking deflectors and using the lower tin mounting holes should prove pretty efficient and easy.

78Kombi : Thanks for that valuable feedback, I was hoping to hear from someone just like you. Do you remember any performance changes when you installed this setup ? Anything elses that needed recalibration, like mixture or timing ?
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You can have it quickly, you can have it good, you can have it cheap...Pick two...

1977 Bay Westy, stock 2.0l FI, Hailing from Quebec, Canada.