TheSamba.com :: View topic - 1974 Muffler Change-Help Please!

Mon Aug 12, 2019 7:00 pm

Hi all. First time post here! Proud owner of a '74 Super as of two days ago. The issue is the muffler the guy has on it is SUPER loud and I want to replace it with a stock to get the Bug purr back.

This is the muffler I'm looking at and attached is the engine. I know i need to block off the Carb heater intakes but my question is with this engine, do I need to do anything with the holes on the top of the muffler or am I just not using them and don't need to plug them up or worry?

Sorry if this is a novice silly question and thanks in advance all.

https://www.vwheritage.com/catalog/product/view/id...gory/3075/

Mon Aug 12, 2019 7:04 pm

If that is YOUR engine then you have a performance engine and a stock muffler is a bad choice and would be too restrictive.

If you want a stock looking and relatively quiet, get the Vintage Speed.. not cheap.

https://store.vintagespeed.com.tw/VW-BUG-SPORT-EXHAUST-SYSTEM-p132804011

Here's one on a Ghia engine i built.

BTW... you need to get the missing engine tin or you'll overheat your engine.

Mon Aug 12, 2019 7:36 pm

Glenn wrote: If that is YOUR engine then you have a performance engine and a stock muffler is a bad choice and would be too restrictive.

BTW... you need to get the missing engine tin or you'll overheat your engine.

That is my engine....which came with the car. The seller told me a stock muffler would be fine to tone down the noise...so that is not the case?

What would you recommend for this engine then if not?

Is the engine tin really necessary? The seller obviously didn't have one on there.

Mon Aug 12, 2019 8:08 pm

imsjry wrote: Glenn wrote: If that is YOUR engine then you have a performance engine and a stock muffler is a bad choice and would be too restrictive.

BTW... you need to get the missing engine tin or you'll overheat your engine.

That is my engine....which came with the car. The seller told me a stock muffler would be fine to tone down the noise...so that is not the case?

What would you recommend for this engine then if not?

Is the engine tin really necessary? The seller obviously didn't have one on there.

The engine tin is absolutely necessary, if you want that engine to last at all. It will overheat without it. Glenn already sent you a link for the vintage speed. They are extremely nice. There are cheaper quiet packs as well, but the vintage speed is awesome. It looks great. It sounds great too. The stock muffler is too restrictive for your dual carb set up, especially if the engine has been rebuilt to a larger size. Also, you'll have to plug the heat riser connections on the stock muffler. The engine tin that you are missing is very inexpensive. It's worth having to make that motor last a long time. Anywhere you can see the ground is space for hot air to be recirculated. Its like a feedback loop. Hot air gets sucked in and the engine gets hotter and hotter.

That's a great looking car. Beautiful color.

Mon Aug 12, 2019 8:12 pm

Plug wires getting ready to cook.

Mon Aug 12, 2019 8:28 pm

imsjry wrote:

Is the engine tin really necessary? The seller obviously didn't have one on there.

The seller is a fuckin idiot. Yes the engine tin is absolutely 100% necessary.

Mon Aug 12, 2019 8:38 pm

73SlowBug wrote: imsjry wrote: Glenn wrote: If that is YOUR engine then you have a performance engine and a stock muffler is a bad choice and would be too restrictive.

BTW... you need to get the missing engine tin or you'll overheat your engine.

That is my engine....which came with the car. The seller told me a stock muffler would be fine to tone down the noise...so that is not the case?

What would you recommend for this engine then if not?

Is the engine tin really necessary? The seller obviously didn't have one on there.

The engine tin is absolutely necessary, if you want that engine to last at all. It will overheat without it. Glenn already sent you a link for the vintage speed. They are extremely nice. There are cheaper quiet packs as well, but the vintage speed is awesome. It looks great. It sounds great too. The stock muffler is too restrictive for your dual carb set up, especially if the engine has been rebuilt to a larger size. Also, you'll have to plug the heat riser connections on the stock muffler. The engine tin that you are missing is very inexpensive. It's worth having to make that motor last a long time. Anywhere you can see the ground is space for hot air to be recirculated. Its like a feedback loop. Hot air gets sucked in and the engine gets hotter and hotter.

That's a great looking car. Beautiful color.

Thanks! I really love the work the guy did on it. And thanks for the advice on the Vintage Speed. I just don't really have 500.00 to spend on a muffler right now. It's just the one on this engine is ridiculously loud and I was told i could swap it out for a stock. I thought it would be pretty simple so I'm surprised to read otherwise now. Any other reasonably priced options for this particular engine to tame it and give it more the classic sound? Thanks again all and sorry but I am a big novice with this stuff!

Mon Aug 12, 2019 9:17 pm

Heat riser block off plate:

https://www.jbugs.com/product/3447.html

Quiet exhaust:

https://www.jbugs.com/product/3647.html

Engine tin:

https://www.jbugs.com/product/8939.html

Mon Aug 12, 2019 9:19 pm

73SlowBug wrote: Heat riser block off plate:

https://www.jbugs.com/product/3447.html

Quiet exhaust:

https://www.jbugs.com/product/3647.html

Engine tin:

https://www.jbugs.com/product/8939.html

But you get what you pay for! I'd fix the tin first off. That's the most important thing. Post better pics of the engine bay and underneath the car so members here can tell you what all you're missing. I'm sure that's not it.

Mon Aug 12, 2019 10:19 pm

73SlowBug wrote: 73SlowBug wrote: Heat riser block off plate:

https://www.jbugs.com/product/3447.html

Quiet exhaust:

https://www.jbugs.com/product/3647.html

Engine tin:

https://www.jbugs.com/product/8939.html

But you get what you pay for! I'd fix the tin first off. That's the most important thing. Post better pics of the engine bay and underneath the car so members here can tell you what all you're missing. I'm sure that's not it.

So having zero experience working on engines, how much of a job is it to install an engine tin? It looks pretty daunting to be honest. Is it needed just due to the kind of engine this is? I've seen tons of old bugs and never heard of this before.

I will post some more pics of the engine in the morning. Thanks again all.

Mon Aug 12, 2019 11:35 pm

It should take you five minutes to install that breast plate (the engine tin). If you think installing that is daunting, you need to sell your Bug now.

Imagine a water-cooled car that some idiot installed to heat up the water-antifreeze coolant for the water-cooled engine. Now imagine that the missing tin you don’t have is like a water heater on a water-cooled car. That’s what you have going on now.

AIR is what cools your engine. Air above the engine seals and tins in the engine compartment is cool (ambient temperature) air. You need cool air to cool your engine. When you’re missing the cooling tins—any, or just one—you’re allowing hot air that has already passed over your engine’s hot heads to be sucked back into your engine compartment, via the cooling fan. In that case, the fan is being forced to cool your engine with pre-heated air.

Your motor will run for awhile, but its life expectancy will diminish much, much faster.

You’ve come to the right place to get advice. Don’t debate with those on here who have years of experience with air-cooled VW’s. These guys can only help you if you listen—and act accordingly.

By the way, the previous owner of your car made it look quite nice. But he was a cheese-dick dandy who went for appearance, as opposed to utility.

Have a nice day,

Tim

Tue Aug 13, 2019 12:03 am

Good “Tin” information here. You have aftermarket shroud and other parts. So research more.
http://www.awesomepowdercoat.com/Original_German_Engine_Tin.html

Not sure what cylinder heads you have on that. But these are important on most heads. MOFOCO heads don’t need them according to Roy (Of MOFOCO)
http://www.awesomepowdercoat.com/Cylinder_head_internal_deflectors.html

Engine to body seal and firewall seal if needed.

https://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=133813705

Tim Donahoe wrote: cheese-dick dandy :lol:

Nobody mocking you imsjry. I’ve had my own experiences with “Cheese-dick dandies” too :wink:

My last experience looked like this :evil:

Tue Aug 13, 2019 4:01 am

Agree as to the engine rear tin. Essential to isolate cool air coming in from outside the car from the air vents, from the hot air coming up off the muffler.

You'll need about half a dozen of these screws to fasten the tin to the existing engine sheetmetal. The rear of the tin simply rests against the rubber seal that fastens to the body at the engine compartment opening. I cannot see if you have this in place already. Screws:
http://vwparts.aircooled.net/Upright-Engine-Tin-Screw-Kit-12-Pieces-p/4506.htm

They use a medium/large flat-bladed screwdriver. Best to install a few of the screws loosely so that you can still move the tin around a small bit to line up the rest of the holes. Then tighten each one. Only a decent twist of the wrist; not gorilla tight. 5 ft. lbs to quantify the torque.

Fitting a stock muffler to replace yours is not complicated, though you risk breaking off the nuts that hold the existing muffler/header to the cylinder head studs. There are ways to get them off without damaging the studs. But as already mentioned, you'd be choking the engine using a stock muffler because the dual carburetors already breathe in more air than the stock single carb. There is more volume of exhaust gas coming out of the heads. The stock muffler is not made for higher volume airflow, but for quietness for all world markets. So choosing a performance muffler that combines good airflow, relative quietness, and good build quality for easy fitment is not easy.

Also, as already recommended, please take a photo of the underside and side of the engine from either fenderwell. TURN THE CAMERA FLASH ON so that this dark area is well illuminated. Then we can determine if you have heater boxes or a simple pipe going into the existing muffler.

Tue Aug 13, 2019 6:03 am

Imsjry - Do you have any service manuals? I strongly suggest you pick up a couple and read them as you would a good novel. You'll need to familiarize yourself with your car and how all the bits work. Granted, most manuals are written for stock motor setups, but the basics for all the systems are in them.

https://www.thesamba.com/vw/classifieds/search.php...rds=BEETLE

Personally, I like the orange Bentley, a British version of the Haynes, and Clymers. The Idiot manual is further down the list but the chapter "How Works a Volkswagen" is great reading for the novice and entertaining as well.

Víctor

Tue Aug 13, 2019 6:29 am

Firstly, thanks again all for dealing with my silly questions and your knowledge. I knew i was getting a older car and was prepared for general maintenance on the "new" engine, but now learning i didn't know what i thought i did about it. Seems like the car is ready to impress at a car show but not so much for everyday driving.

I've attached some more engine pics which i hope gives all a better idea of what's under there.

Firstly, the obnoxious muffler noise. Now i know a stock replacement would not be a good idea (not what i was originally told), do you guys think this would be suitable for decent performance and would tame the noise? It looks almost the same as what's on there, but specifically mentions the sound being similar to stock. I assume this is more due to the tips (?) https://www.jbugs.com/product/3417.html

Secondly, if i'm reading right, the Engine Tin wouldn't take much to install (someone mentioned 5 minutes?) I was thinking the entire engine would need to be taken apart and put back together for it. I see some different responses here on things to purchase, but from the engine pics i've added here. could some kind souls tell me specifically what i should be adding?

Again, thanks again to all. I value your experience and knowledge!

Tue Aug 13, 2019 6:38 am

Because your motor is a performance engine a stock muffler would restrict that performance gain. If your not worried about the loss of performance I don’t see a problem with a stock muffler. Worst case is it runs like a stock motor. Most of us are happy with stock motors.

Am I wrong?

S

Tue Aug 13, 2019 6:44 am

Murmsk wrote: Because your motor is a performance engine a stock muffler would restrict that performance gain. If your not worried about the loss of performance I don’t see a problem with a stock muffler. Worst case is it runs like a stock motor. Most of us are happy with stock motors.

Am I wrong?

S

For the record, I am not really concerned about any performance loss. I just want it quieter and to run at least smooth, not necessarily like a race car. If the stock muffler can accomplish that i'd be happy.

Someone did mention needing to plug up the heat riser holes on the stock so not sure how that would affect things or how to plug em.

Tue Aug 13, 2019 7:08 am

imsjry wrote: Hi all. First time post here! Proud owner of a '74 Super as of two days ago. The issue is the muffler the guy has on it is SUPER loud and I want to replace it with a stock to get the Bug purr back.

This is the muffler I'm looking at and attached is the engine. I know i need to block off the Carb heater intakes but my question is with this engine, do I need to do anything with the holes on the top of the muffler or am I just not using them and don't need to plug them up or worry?

Sorry if this is a novice silly question and thanks in advance all.

https://www.vwheritage.com/catalog/product/view/id...gory/3075/

Where in Wisconsin are you? YES, YES, YES you need the engine tin. If you don't care at the moment for performance, then the stock muffler will be just fine.

Tue Aug 13, 2019 7:09 am

You can read Muir's Idiot's Guide book on your computer or ipad/kindle if you want. Here is a link to the book as a pdf. It is written by an old hippie who approaches VWs as a lifestyle of maintenance in which anyone could participate.

http://www.users.on.net/~agonza/dev/How%20to%20Keep%20Your%20VW%20Alive%20OCR%20done.pdf

Tue Aug 13, 2019 7:30 am

I am not big on the aftermarket chrome engine sheet metal. Sometimes in the fan shroud does not have the correct deflection vanes like the factory stock fan shroud. I wonder how much other sheet metal is missing like the little deflectors under the cylinders. With that said if it were my engine I would replace all of it with proper German sheet metal.
Now the rubber oil lines, swap them out with steel braded lines.
If you are near other Samba member they may assist in correcting the problems with the engine.