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MG MGB GT V8 Factory Originals Technical - What Happened??

The following message was lft by Ted, NH but I couldn't respond. There was no reply board.


Get the book by Roger Williams. Tells you all you need to know. But I'm not sure the V6 would be all that bad. I love my V8 and I've had it for years but I detest the overheating problem -- I've done everything humanly possible and simply thrown gobs of cash at the problem and I'm still not where I wanna be. On a hundred degree day, bright sun, traffic, it's a no-go. Can't hack it.

I don't know if those V6s have the torque that the bigger V8s do -- the torque's what really makes the experience of a BV8 so magical -- but if they come close, the V6s sure look like neat little installations. And they appear pretty bombproof. Really the *only* thing I don't like about V6s is the sound ... no matter how you slice it, they're not gonna sound the same. But they can still be made to sound more than acceptable.
Dann

Ted,I love the sound of a V8 also. We at British Car Coversions make the Killer B Conversion. We are the only manufacturer of a kit for the 3400 (3.4) Front Wheel Drive to RWD conversion. We compete with other manufacturers that uses only the rear wheel drive V6.

Not wanting to appear negative and taking a risk of some toe stepping I would like to say we have no overheating problems and the little V6 and will smoke the ordinary 3.5 V8 not to mention it is half the price for an installation. I really like the V8's but the perpetual problems with them made them undesirable for me so I looked for an alternative.

The reason that the sound is so mundane with a lot of the installations is the manufacturers of the Camaro type engine conversion sell a simple, untuned exhaust manifold that dumps the exhaust from one cylinder back and forth in a cross pattern into the manifold before it exits and then it isn't a resonable purge. This creates a lot of reversion and back pressure at the cyinder exhaust port. It sounds to me like several weak cylinders when you listen to it from the muffler end. To make things worse I have seen these system with no crossover pipe which makes them sound even stranger. Not all of them sound that way but most of them do. We recommend our tuned header system with a cross over. Our engines rev extremely quick. Our set up sounds like a Ferarri from hell. I know you would like the sound, it's the first thing people notice. Dann
Dann

Sure looks like a clean little install. This computer monitor's pretty small, but I don't understand what's going on in your picture ... where's the fan? where's the water pump? Do you use a remote electric water pump? ... call me a traditionalist but I'm still dubious about those for road use. Just one more thing to go kaput! But I am amazed how small that motor is -- bet it's not very heavy either. Seems like there would be more than enough room to install A/C as well! If you'll send over a GT with an A/C and 200bhp or so you can have my 4.2 V8! I don't need any more speeding tickets ... I'd rather keep cool!
Ted

Pipe size, type of muffler, and the head design (chamber) do affect the sound. Case in point the Gen II sound much different than the 3.1, 3.4 Camaro or a 2.8 Fiero and the reason...Alloy heads with different chamber design.
One of the best manifolds produce by GM is call the horn it's use on the 1996 LT4 Corvette and others Corvettes as well. All of the cylinders dump the exhaust into one pipe. If all the cylinders would fire at one time then it would be a problem, on the same note the tri Y system is one of the best systems to excavange the exhaust from the cylinders. Without getting into the physics, one cylinder helps the other similar to a Naca scoop but in reverse order thus helping to produce more torque.
Long tube headers are great for racing, no just any long tube header will do the job tune or otherwise. The V6 is critical in the exhaust system it must have some backpressure.

Now, I wonder why GM supports the cast iron head engine in off road racing and not the alloy head V6. Another very effective exhaust manifold is call the log, which it was used in the Fiero. The Fiero exhaust is known to be one the best flowing systems. All ports dump into a common tube, the common tube exits to the Cat and then to the muffler. GM soend allot of time on the fiero exhaust.
On the simple exhaust manifold as it was called, one cylinder will help the other by creating a vacuum thus helping to extract the gases, and yes it's a simple and effedtive way to exhaust the gases. No all the cylinders fire at the same time, this would create a bottleneck and yes lots of backpressure.
The V6 works best by using a true Y pipe after the headers and then into a single pipe to a muffler.
2 inch into a 21/2 or 13/4 into a Y pipe with 13/4 out to the muffler.
The must popular headers for the small block Chevy and small block Ford are short tubes.
For all out racing, a large tubes three into one and about 26 inch primaries into a 2-inch collector with crossover of the same size. All of this depends on valve size, camshaft, and induction system. The crossover pipe would have to be size in the dyno; it could be smaller than the exhaust tubes.
Headman use to sell a set of headers for the front wheel 2.8 the primaires where 13/8 by 28 inches long into a 2 inch collector. They created backpressure by reducing the primary pipes.

Bill Guzman

Ted, not to worry. The remote pump that we use now is guaranteed for 5 years. The water pump in the picture was driven by a small motor and notched belt. It was working after 5 years of continuous use when we replaced it this summer in favor of a remote pump. A lot of the rice burners have used this type of pump for a while without incident. The fan is behind the radiator. I attend a lot of cruise-ins. I get a lot of input from the owners of various cars that use this type pump. If you are into fine tuning this is a bonus. BTW our car weighed nearly 200 lbs less then the lightest V8 car in Grand Rapids a few weeks ago. I am currently doing a air job for a customer. It takes a lot of time to set up for the first time. Thanks for your enthusiasm. Dann
Dann

Dann,
I hate to nit pik, but your car was only 30 pounds lighter than the lightest V8 in Grand Rapids. My '67 B with a 215,T5,and narrowed Ford 8" differential with all of my luggage and the tools I carry on the road trips weighed 2150. According to the newsletter yours weighed 2120. I also noticed that you didn't have bumpers. My car is a real '67(not backdated) with the original aluminum bonnet and bumpers with overriders.
That being said, I do like your conversion. Very good installation.

Al
Al Wulf

Dan:

Are there in fact more pictures of your car(s) out there? Your Web site has the same pics as two years ago and promises to be finished soon. Have you started another site? It would seem that a lot of development has occured in the last two years and I would love to see some of it!

Pete
Pete

Al, I stand corrected. My guys related that info to me. Even so my car body, which is a lot heavier than your car in full trim, is original except the bumpers are gone but the Sebring front and rear valance make up for the weight of one bumper at least. Other than that it is in full trim and this is very commendable, considering. Thanks for the compliment.Dann
Dann

Pete. I never make a promise I couldn't keep. :-) Did I really say I promised? Just kidding of course. I'm really sorry about the website. I have sent the info to my webmaster but he hasn't installed it yet. I have some pix of interest, would you like for me to upload them to your email? I have had the 3.4 V6 engine for my MGB Speedster out and put back many times in order to make improvements in the conversion design. The lastest improvement is Air Conditioning! I have had numerous request from the B owners in the warmer states for air. You are very correct, I have made a lot of developments. I will be working on a more affordable remote electric pump conversion for the 215 V8 this winter. Let me know about the photo's by emailing me. I not always sure I can get back to these columns in a timely manner. Thanks, Dann
Dann

This thread was discussed between 19/09/2002 and 23/09/2002

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