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MG MGB Technical - Engine Selection

We are in the final stage of caring for an MGB after many years without a true sports car. The most promising unit we have found is a 67 tourer with the body restoration and paint complete but lacking the engine and transmission and needing the suspension done. Our question regards the best engine. I have researched the V-8 and V-6 options as well as rebuilding and improving an original 1800. The rebuild holds the most attraction to me. However, we would like air as we intend to do extensive driving in the southern states and are concerned with reliability and performance. I have access to a complete Honda VTEC four drive train (rear wheel drive) parts car. This would seem to be an almost a natural fit. Light weight, good power and has the accessory drive for AC.

Can anyone suggest if this would make sense? Has it ever been done before? Anything we do we will be done such that the car can be returned to original but as the numbers wil never match we want to consider all options first. Any advice and direction is greatly appreciated.

Norm Peacey
N. A. Peacey

Norm,

See http://www.britishv8.org/swaps/joesspit.htm for a Spitfire with this engine. Not the same as an MGB, I know, but it might be of some help anyway. The car's owner, Joe Curry, is real helpful and should be able to offer a lot of tips for you.
Dan Masters

If reliability is your main concern, a well rebuilt standard unit should be pretty bullet proof. It also gives you the advantages of easy parts availability, simplicity, and a car that is going to appreciate in value. I run an overbored (1995cc) as my main car that has been more reliable than the modern Saab it replaced. It's fast enough for the car too.
Steve Postins

A Rover K series and the engine that predates it (of which i forget the code, but is either M, T or O) fit the B with minimal fuss. It is my understanding that at least one of these engine types has similarities with the Honda VTECs.

At which point, then yes, it should fit.

Aircon was an option (albeit possibly dealer fit) in the US, using the standard B engine, so don't let this put you off trying the B engine for size.

I seem to recall whatever the engine above was (M,T or O), it requires the heater box to be removed for the fit and possibly some bulkhead mods. This may not help your policy of trying to return th eccar to original after you have finished with it.

HTH ~PHIL
Phil

You are at the crossroads of a potentially long and difficult path.

Check the transmission tunnel size on '67 and earlier MGB's as some of them were fitted with the
3-synchro trans and had narrower and smaller tunnels. This may, or may not, factor into your swap
plans.

Although it is not impossible to fit a V8 into an earlier MGB - the later, rubber-bumpered MGB's are the
best candidates for this as they had the larger (all synchro) transmission tunnel and the engine bay was slightly reshaped to accomodate a V8.

I've seen folks swap in modern 4 cylinder engines into MGB's however almost all of the owners have
said that one of the toughest things to do in the conversion is to wire in and reconfig the computer
controller and all of the assorted sensors and guages.

All things being equal - I'd either rebuild the OEM engine and trans...or get a recent Mazda Miata (with
factory air conditioning) and then be done with it. With the money saved, I'd go and visit glorious
London for several weeks ...and try to haul back one of those cool London cabs.
Daniel Wong

I agree with Daniels sentiments. The 67 is considered a prime year for the marque in North America, and if it were me I'd stay stock. If you want more HP and torque the Moss Supercharger kit is an easy mod that appeals to me. They did a nice job of making it look like a period accessory. You can increase power by 40% or more with a stock engine, and if you sell the car you can easily remove the setup and install it in your next MG. And it is probably cheaper than most engine swaps.
Andrew Blackley

Thank you everyone for your prompt replies and information. I like simple and modifying an original 1800 is probably the logical thing for an analogue type like me. I have now seen talk of the 2000 cc engine and also a cross flow head.

I will proceed with the purchase of the 67 tourer and look for an engine and transmission to modify. I have also found a source for air from a Triumph web site that should work on the B.

Thanks again, I am sure I will be back with 4 cylinder questions.

Norm
N. A. Peacey

Norm. By your reference to "driving in the southern states", I assume you are one of our "winter visitors" to places like Arizona. In winter, you do not need air conditioning. In summer you need it desperately, but it adds both complexity and extra heat into a cooling system that is very marginal for summer time operation in a place like Arizona. This is why I do not have it one either or my daily drivers, nor on my daughter's daily driver.

The larger engine would also be of concern. I would much prefer a more "standard" rebuild than one of the 1.9 to 2 liter specialty engines. First, the specialty engines are marginal to build. Not all blocks will work for them and you do not know if any block will until you bore it. The cylinder walls tend to be significantly thinner than standard and the heat injected into the system somewhat more. Some report excessive oil consumption because of bore flex. Such conversions are not popular in my area and I know of only one fellow who has done so, adding a cross flow head. He has built a very powerful, very unreliable engine. If it were I setting up such an engine, I would look at a relatively standard overbore with a CB cam (or a Piper 270 cam), a modified cylinder head and K&N air cleaners. I have found this specification to work quite well for both touring and in town driving. An overdrive transmission is nice for highway cruising and for in city driving on the various limited access roads.

There is no dealer service network for MGs in the US. Often, there may not even be any competent mechanics willing to work on the car. I know of only two-three compentent shops in Arizona who will work on MGs and only two in New Mexico. Thus, if you are going to be doing any touring in the US, it would be wise to check out the availability of competent repair shops in the areas you intend to be in. I would also try to make contact with any MG clubs in the areas I would be travelling. Often, they will know of sources of parts which are locally available, know which are the repair shops to use and which to avoid and can provide area information which may be of use to you.

Danny Wong has a very valid point about the Miata with factory air. There is an existing dealer network in place, there are specialty shops in some places (we use one in Phoenix for my younger daughter's Miata), there are readily available parts and the car has been engineered to run with an air conditioner. There are also Miata clubs in many areas. I have done long distance touring in the MGB and the Miata and do not find a great deal of difference in winter. However, in summer the air conditioning on the Miata is very welcome. I also do not travel to a fixed schedule, have a cell phone and have time to spend several days awaiting parts and repairs if that should become necessary. (It has been in the past, but not with an MG.) Look very carefully at what you intend to do and how you intend to do it before making a final decision on what to buy. Les
Les Bengtson

Les, thank you a very informative response. I have made an offer on the engineless body after investigation by an very knowledgable MG/Triumph mechanic here who advised me that the body is nearly 100% original. He advises that the suspension is easily upgarded as many items such as tube shocks are already in place. He is advising a stock displacement engine with minor mods and an OD addition. Seems pretty much what you are saying as well.

He has said if AC is a must that Vitage Air offers pieces to do the whole MG including a much better heater that will rob very little power and only requires a smog pump pulley.

We wil proceed slowly.

As to the Miata, we tried, I do not fit.

Thanks again, Norm
N. A. Peacey

Check out this site

http://www.mgbmga.com/tech/
Fred Horstmeyer

Norm. It shoulds like you have a good handle on what to do. I would be interested in your experience with the AC. I find the MGB cooling system to be very marginal for summer driving in Arizona. I would suggest that you look at upgrading it for use with an AC. Several people have suggested replacing the existing radiator cores with a new core from Modine and this is covered in the archives. That will be my next experiment as I try to learn more about this subject. If Arizona is one of the southern states you are visiting, or New Mexico, I have some contacts who can provide information on repair and parts services. Feel free to contact me. Les
Les Bengtson

This thread was discussed between 24/06/2003 and 26/06/2003

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