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MG MGB Technical - Carbs for econotune head

I'm thinking about sending my 74B head to peter Burgess
for an econotune top end job. What's holding me back is the fact that the head has never been off the engine and it runs fine. I do not drive real fast so high performance is not a real need. The car (a California car) came with HIV4 carbs which also work well. Will these carbs be OK on an econotune head or should a change be made? Perhaps a different jet or needle? Thanks Bob
Bob Ekstrand

If you are bent on getting a Peter Burgess head why not get a replacement head and send that one to him. Seeing yours is running well I would suggest leaving it alone and he will build up your replacement head.I would assume he would completely rebuild your existing unit if you sent that one.
This way your car will not be down more than one day.
My motto is if it ain't broke don't fix-it.
Sandy Sanders

Bob, you should put your question directly to Peter. He generally answers email and he won't give you any bull-sh*t. He might even reply here as I know he reads this board from time to time.

He's not in the business of selling things just to take money from a customer. He genuinely wants the customer to be happy with his engine and I have had nothing but a good experience from dealing with him on several occasions. Often Peter would rather make an existing component work properly than strap on something new. You can get his contact details from his web site.
Mike Howlett

Bob. I would second Mikes advise. Contact Peter directly with your questions. However, I have the same reservations which Sandy mentions. A modified cylinder head is the basis for building a modified engine. To fully take advantage of the modified cylinder head you need to have in mind what your goal are (increased economy, increased performance, better performance in a certain rpm range, et al). Simply bolting on a modified head to a stock engine, especially one with a number of miles on it, may not be the best idea.

When I decide to build an engine, I sit down and write out what I want the engine to be able to do. Then, I look at what parts and/or modifications need to be made to the engine, as part of the rebuild process, to get to those goals. I also note that some goals, such as higher top end speed and faster acceleration, require that modifications to the rest of the system. A car that goes fast and accelerates like a rocket can be a problem if it does not handle and stop well. Rebuilt suspension, upgraded brakes and different anti-roll bars may be a part of the total modification if the system is to be safe, effective, and provide the increases you are after.

You may wish to define your goals, then what modifications to the system will be necessary to accomplish those goals, then start looking at what it will cost to achieve your goals. It can be both an expensive, and a time consuming, process. Especially if your car is already running well and doing most of what you want it to do without any modifications.

Les Bengtson

I agree with what others have said, get in touch with Peter directly. My experience with the Econotune head on the 3 main engine in my ī63 roadster (the head itself was cast in december ī62) is that you get noticeably more pulling power at moderate revs, just as Peter says on his website. I donīt drive my car real fast either. I also feel it has contributed to a smoother running engine, possibly because the combustion chambers have been equalized?

When my original cylinder head cracked and I installed the replacement head from Peter I was of course keen to optimize everything, but had trouble adjusting the carbs correctly by the book. Closer inspection showed lots of wear, so I decided to replace them with new HS4 carbs. With the standard needles, the engine now runs almost like a six cylinder!

It may just be my imagination, but it almost felt as if the "new" Econotune head highlighted the defects of the old, very worn carbs. Anyway, I am really happy with the conversion.

I agree with Les that you should define what YOU want from YOUR car. I think I have found the ideal spec for MY needs and MY car now. A smooth running engine with excellent pulling power: Econotune head, carburetters and a distributor that is not worn (important!) and all adjustments spot on. Light steering and responsive handling: Vredestein 165/80 tyres with 28 psi front and rear, GT springs at the rear, new standard shock absorbers all round and blue Autobush polyurethane bushes everywhere.

It is surprising what gradual wear does to the car, so just reconditioning or renewing of vital components may give you quite an improvement.


"HIV4 carbs" ?

Sounds a bit queer to me ...
Paul Hunt

Hi Bob

The Econotune head will run well with everything else standard, you would only have to change the needles if you fitted free flow air filters such as K&Ns.

The Econotune head is how the factory should have done them in the first place with better control over casting/ core placement and better seat cutting and valve manufacture. Mind you. if 'they' saved $10 a head not doing the extra work.....think of all the $10s added together, nice profit for someone!

With regard to sending a head over, is it cheaper to buy an outright casting from us at
peter burgess

Thanks everyone for your comments, especialy yours Peter. I'm after improved normal performance as high RPM and speed are not really important to me. The car is such a nice cruiser I almost prefer going slower because I get a lot of nice comments about it. Its amazing how many people used to own a 'B'. Thanks a lot!
Bob Ekstrand

Please, what's exactly meaning "outright casting"? Just coming from casting factory, a brand new one?
Many thanks.

Renou. All of us native English speakers read it as "buy the casting, outright from us" which indicated that Peter was asking if it would be less expensive to purchase one of his used and inspected cylinder heads or whether it would be less expensive to purchase a used cylinder head in the US, have it stripped, cleaned, and crack inspected, then pay to have it shipped over to the UK for modification. Not really a question because any cylinder head, here in the US, which is crack inspected is going to cost a lot more than the L100 that Peter is charging. A friend recently had nine used cylinder heads inspected, all of which showed cracks.

Good catch. It will both help us keep on our toes (be more aware of what we have written before hitting the "submit" button) and remind us that not all of the enthusiasts we are communicating with have the skills to interpret our less than perfect writings. A good thing to be reminded of from time to time.

Les Bengtson

Thanks a lot Les,
All appologies for the request, but english is not my mother tongue and sometime specific idioms are not that easy to imagine strictly. Thanks for your explanations. I am in the same situation as Bob, and I already meet the "crack head syndrom" which catches you back unfortunatly.
Best regards.

Peter, does that mean your Econotune heads are only $10??
I'll have 2 then!!

Colin Parkinson

Colin. Yes, Econo-Tune modified cylinder head are only $10 (US). But, that is 1962 US dollars which in 2009 means that the current Econo-Tune head is a bargain at anything less than $1,000.

Les Bengtson

Nice logic Les.

peter burgess

I would back what Peter has said. I fitted an econotune to my 71 standard engine. It boosted bottom end torque but strangly not fuel economy. I can now run on unleaded of course. Everything about my engine is standard and its done 125,000 miles. It hasn't been re- bored, but I've changed almost everything else. I honed the bores and fitted new rings which has virtually stopped any oil consumption. Performance is a match for other B's and midgets I run around with. Climbs hills effortlessly. Never rev above 5000, no point.
Paul Hollingworth

Thanks Paul, you told me everything I was looking for! My 74B has 125k on it and I have done nothing to the engine at all other than tune ups and such. I'm not expectng any improvement in mileage and we have only had unleaded gas here in the states for many years now. I am considering new rings only as well. Did you use standard size rings or a different size? Thanks Bob
Bob Ekstrand

The Econotune head, will, if driven in a reasonable manner provide more mpg than a standard head.The head is more efficient than a standard one in terms of airflow and CR ie effective and theoretical CR. Usually people seem to go a little faster for the same amount of fuel. Most customers report a significant improvement in mpg if driven 'nicely'.

peter burgess

Hi Peter ... I've been driving like a granny since you fitted my Econotune! I'll be reporting on my fuel consumption when I've done a few more miles.

Of course, I have more power and I can run on regular fuel so can fill up anywhere, but I suspect I get more miles/pound with super. Time will tell.
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This thread was discussed between 21/07/2009 and 25/08/2009

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