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MG MGB Technical - Need exhaust sys..Which one?

It's time to upgrade the exhaust on my 74 1/2 GT. Hoping for a little advice on what to buy. I sure liked the sound of a B equiped with an Anza style sys that I saw recently, don't see this often though. Most systems from Moss/ect seem to look alike except steel vs stainless. My engine will remain stock. I do have a header from another car that I can use..Everything is stock now. Any recomemdations and Likes/Dislikes??

Morgan
Morgan

Hey Morgan,

I'm a big fan of having a system without the front silencer box... I removed mine (it was broken) and replaced it with a straight-through pipe and I'm pleased with the result... a nice rumbly idle and bassy sound at lower revs, but normal noise levels once I wind the engine up.

The professionals on the board will I'm sure advise on what affect changing your exhaust system will have on mixture etc. but my plugs (and, in fact, the whole combustion chambers) are the right colour and I haven't changed my needles or air filters or anything scientific like that.

I believe several standard-bore systems are available with just the rear silencer.

ttfn,
--
Olly
Oliver Stephenson

Morgan-
When you say "upgrade the exhaust", I presume that you're looking for a performance exhaust system. Right now there's two systems that are time-proven: The Peco system (available from Brit-Tek at http://www.brittek.com/ ) and the Maniflow system (available from Advanced Performance Technologies at http://www.aptfast.com/ ). Both are well-made and should install with no problems providing that the appropriate header pattern and diameter is used. The question at this point is: What is the diameter of your spare header? On the other hand, if by "upgrade" you mean an essentially stock system that will last longer, then take a hard look at the dual box stainless steel Falcon system. It can be had from Victoria British at http://www.victoriabritish.com
Steve S.

I know it was not intended for me, Steve S. but you have written the most concise, complete distillation of MGB exhaust systems I have seen. It answers or opens up answers to every Q one might face, from header flange to marketplace. Thank you.
Ken R
Ken Rich

Ken-
Thank you.
Steve S.

I have to replace mine too. Anybody have any experience with the "Monza" system. I think its made by ANSA. It was recommended by my supplier but I haven't seen it yet because it's a special order.
Dave Pearn

A lot of people rate stainless systems (i use one myself) but also noted that the stuffing used in silencers often wore out before the pipes ever did and sounded noisy and harsh. I think though most stainless systems have lifetime warranties so that the box should be relaceable under warranty when stuffing becomes ineffective.

Since reading about performance tuning, if one wanted to gain a little BHP effortlessly whilst changing exhaust systems, the peco system appears to be the one to go for. This is a freeflow manifold with single rear silencer system using slightly normer than standard 2" dia tubing. However it seems to be the back box that is the unique part of this system (it does not uses stuffing - but reflective plates to silence andloses less power through these), the manifold des not really contribute to the power gain over or above any othertype of 'freeflow' manifold.

A company in the UK called Double S are well respected and make a similar design exhaust system to the peco i.e. 2inch dia tub, single rear silencer.

I think if i ever changed my system again, i would look to purchase the freeflow manifold and tubing up to the rear box from dounble S, (which is stainless steel and therefore should last a lifetime) but adjoin it to the proven performance rearbox made by peco. Tht way you have the best of both worlds; a system that should outlast the rust capabilities of the car, with the proven record of the quality peco system.

JMO ~PHIL
Phil

I have had the Anza or Monza (do not know if they are the same, but the one that has both a front and rear silencer/muffler with the rear having a single tube coming out, then branching into twin, chrome plated tubes) on one car currently. I previously had the same system on my 79. I do not like the sound of either. On the 79, I switched to the Peco system, including the header. This is a "big bore" system with a single muffler in the rear. I liked the Peco system so well that I have purchased another for my 68. I have only found two problems with the Peco system. The paint is cheap quality. You need to remove it, at least from the header, and either paint the system with high temp header paint or have some other form of finish applied. On the 79, the brake servo unit prevented installing the header. I had to remove the motor mount bolts and lift the engine up and to the right to get the header in properly. Have not installed the system on the 68 yet, but Bob, at Brit-Tek, tells me it is much easier with the non-servoed brake systems. I recommend the Peco. I would not recommend the Anza unless you do not mind a "tinny" sound to your exhaust. (Peco is a deep, rich sound.) Other alternatives are Midas and custom muffler shops. When the rear hanger broke on my original 79, while I was traveling cross country, the BL dealer recommended going to Midas rather than driving to Austin for a BL muffler. He told me the Midas muffler would be less expensive and hold up longer. It did. Custom muffler shops, at least the one I deal with, are not very expensive and can build up a custom system which can perform quite well. Les
Les Bengtson

Thanks Guys..Car will go in for a clutch job and O/D trans swap next week. Then I may order a Peco sys less header..Sounds like the stock manifold should work fine

Morgan

PS ..Les, Your posts are always very helpful
Morgan

i would agree with les on the custom muffler shop. i have had sereral systems put together from a pro muffler shop and was very pleased. if you find a good one, they know what they are doing and are not very expensive.
mike

Do we trash the standard cast iron manifold, for a tubular double S freeflow manifold.?

I'm sure I've read on previous threads that the cast iron manifold was an overall better bet than the tubular.

Confused I am.
Tom

If you read "How to Powertune MGB engines by Peter Burgess, he recommends the standard manifold as being of good design, but also recomends the Peco complete system, which gives a small gain in BHP.
I have the Double S system with bomb centre box, but would not recommend it, sounds very tinny and was very difficult to fit. Also the pipes from 1 and 4 ports are not the same length and I believe they should be for a tuned system.
Recently saw a Moss system which used the standard manifold with two down pipes joining into a single pipe just under the car then straight into a large single rear box. This gave a superb sound as close to the original as I have heard. It is also Stainless so will last a long time. Certainly will change to it as soon as ££££'s permit, think it is made by Falcon
Regards
Graham
Graham

I'll second the Falcon big-bore stainless system that Graham mentions. I've installed one on my '69 B -- the fit was great, the sound even better!
Rob Edwards

Here is another vote for the Falcon stainless big bore system. I intstalled one on my 74 1/2 B Roadster, and agree with all that was said above.

Cheers, Doug
Doug Keene

On the Double S system:
I've installed a full Double S big bore exhaust system on my car and I have not had any probs with temperature rising or anything else for that matter.
And it makes a very nice, warm low sound at low revs and a really throaty sound at high revs.
I just love it!
Can't comment on the performance gains though, I was too busy listening ;-)

Regards,

Alexander
Alexander M

I have to vote for the Ansa exhaust (sorry, Les!).

I find the sound unbeatable, and follow the advice I've heard that, except for a complete Peco exhaust system (including header), the stock manifold gives excellent overall performance and the Ansa is a free flow design. It is not cheap, however. I believe I ended up around $400 for mine (there was a mix up in verbal orders and I ended up having to buy the two sections separately). The system is extremely robust - the one I just replaced had been on the car since 1989, and only needed replacing due to hits to the center muffler, probably caused/aggravated by weak rear springs. The other Ansa on my wife's roadster has been on for a longer time - probably good for another 10+ years.

They are hard to find - I got mine at: http://www.britishcarpartsco.com/index.htm
after doing some Googling.

BEWARE OF IMITATIONS! The Monza exhaust (as sold by Vicki Brit & others) is a direct knock off and cheaper - but made of inferior material and has a reputation for extremely poor durability - a matter of a few years rather than a few decades. Avoid.
John Z

Graham/Rob/Doug...

I believe Moss has a Falcon Sys on sale right now, little over $200. Is this the one? Is the sound pleasant without being offensive/to loud.

Morgan
Morgan

Moss part number 444-165 looks like the one I installed. I find the sound quite nice -- louder than stock but not raspy or obnoxious. My wife thinks it's too loud. ;-)

I found that the engine's state of tune influence the noise levels quite a bit. Better tuned == quieter.

HTH!
Rob Edwards

What about ground clearance on such exhausts?

I suffer quite a lot with low ground clearance, I scrape over pretty much all the sleeping policemen.

Jamie
jamieo

I used the Falcon stock stainless exhaust system from Moss on sale ($200.00), it fit well and sounds good , like stock . easy installation with all stock hangers and clamps .

_No_ power increase of course but my driveway is steep and the old ehx. system scraped when driving up the curb (?kerb?) and no longer does so .

-Nate
Nate

All depends on the sound you want and the look of the tail pipes as the performance differences are negligable.....
T.E.D.

Can't say if mine scrapes worse with the exhaust, as I never drove the car with on original-type exhaust on it. (It had a cobbled-up monstrosity on it when I acquired it...) I will say it does scrape over some speed bumps (sleeping policemen).
Rob Edwards

One of the advantages of the Peco system is it only has a rear muffler. Peter Burgess recommended removing the middle muffler/silencer in his book. I did that because the middle muffler had been damaged by speed bumps and had a custom muffler shop run a straight pipe where the muffler had been. Corrected the problem and worked well for many years. Les
Les Bengtson

Has anyone out there in MG land used the Maniflow exhaust system? Any comments or criticism?

Thanks.
Brian

Brian-
I helped a friend install his single-box Maniflow exhaust system. It went right on with no problems. The sound is a bit different than that of the Peco system on my car. The Maniflow has a deeper, more bass note, while the Peco sytem has more of a rich baritone note. Both are noticeably louder than the Original Equipment system, but not to the point that your neighbors will think that you're obnoxious.
Steve S.

My 2¢ worth:
The stock manifold (up to 75, of course) is very, very good. No headers are necessary.
That said, the Peco Headers MAY be slightly better. They seem to be very well designed, taking the siamesed head into account. I don't have personal experience with them, but they seem like a nice piece of work. Any other headers aren't going to make a difference, or much of one.
From there back, my best experience has been with a local muffler shops custom job, which was VERY good, and my worst was with the Monza, which was just terrible.

One note on custom jobs. They need to route around the rear axle carefully or the exhaust is likely to get too low.
Baxter

A few notes about the PECO header and exhaust system. I installed the PECO system in my MGB when I did my total rebuild and let me pass on a few things I have observed.

1) Find a chrome shop that also does Jet Hot coatings and see if you can get your header included in one of their orders. The chrome shop that did my chrome work did this for me and it only cost me $40 to have my header Jet Hot coated, much less than the $150 to $200 if I had sent it in by myself. Evidently, Jet Hot does work in batches and charges the shops a fixed rate per batch.

2) Strip the paint from the entire exhaust system and paint with a good high quality high temp paint. The PECO paint is crap, to be honest.

3) The sound from a stock engine will be quite a bit louder than what you are used to, but not obnoxious. The sound from a highly modified engine (as what I have in my car) can be incredibly loud at full throttle and basically sounds like a straight pipe. Even at idle, it is fairly loud. Therefore, if you have neighbors that live close by and you like to fire up the car early in the morning, be forewarned that it will be noisy. The good news is that I can pull up to some rice rocket with a resonator exhaust, smile at the driver and then hit full throttle and drown out both his car and the boom box inside (Yes, I know this is childish, but you have to have some fun).

4) Be prepared to have to modify the mounting washers for the header studs at the head. PECO uses a thinner mounting plate than the stock manifold. The easy way to fix this is to cut in half washers of the appropriate thickness and glue the halves (I use JBWeld) to the mounting washers. This solves the problem.

4) The system works great and has held up superbly. The quality is good and I am pleased with PECO's work.
Ron Kluwe

Just one more voice for the PECO here. Previous posts have been right on the money about the tone and volume. I have used it for two years in daily driver and motorsport and have had no problems. Also, I have pulled it on a few occasions to switch out motors or to add a panhard rod. I was pleasantly surprised at how easily it separated and went back together - many less robust systems may not be so forgiving. When installing for the first time, I had a few intake manifolds with different thickness in the flanges and found that one was a match while others were not. I actually used one that had a thicker flange and simply milled it down to match that of the PECO manifold. Ron's solution sounds perfectly workable, too. Dean
Dean Lake

Another vote for the Falcon system. Being SS it will outlast the sills (as long as there is no damage from bumps & potholes!). Mine bolted right on with no problems, and you don't have to fret about removing the paint and repaining as with the Peco. If you're not going all out for performance this is the way to go, using the stock (pre 74) manifold.

It's also cheaper!!!!
Bud G

I'll add my voice to those who don't like the Monza system. I have that one on my '71. I like the looks of the twin chrome exhausts, but installation was terrible...spent several bucks at the local muffler shop to get everything rewelded to actually fit. And the sound is a bit loud for me, after an hour or so of cruising.

Dave Tye
David Tye

I'm not sure I see the need to repaint the Peco system at all, while it may well please some to do so. After a couple years, it still looks pretty good to me. I did not choose the system based on that issue in any case, but then I've never really considered the exhaust system an appearance item. May I suggest a big anodised gold exhaust tip to improve looks, sound, AND performance. ;-) Dean
Dean Lake

This thread was discussed between 08/12/2002 and 14/12/2002

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