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67BGT

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I have a 67 1.8 B engine that I am going to rebuild. I want to Bore out the cylindes, and get a cam and maybe do some head work. I would like some input on this matter. Where is a good place to look at cams? How much should I bore over? Has anyone done this before and can give me any advice or tell me about there outcome. I also read earlier about some B's that were pushing 130 horse. I was wondering if there were any 1\4 mile times, I would really love to see how fast they would run. Any response would be greatly appreciated, thanks.
 
If you're interested in doing some reading on the subject, and you haven't already found it, Peter Burgess's book offers a pretty thorough discussion. I think it's called "How to Power Tune MGB 4-Cylinder Engines," or something like that.
 
I remember reading somewhere (maybe in the Moss Motors catalog) that an overbore is fine, until you get up to two litres, at which point cooling or something is compromised a bit. Dad's B is overbored (we don't know how much), and has an uprated cam. No idea what it's putting out, but it has a nice slug of torque low down in the rev range. Makes it very nice to drive, it just pulls away beautifully.
-Wm.
 
and a link from my website on the overbore topiclink
sorry for the shameless self promotion
thumbsup.gif
 
Why do you want to bore it?? Boring is only worthwhile if it needs it!! As far as cam, man did I get a good one!! I am sure that I can look up the lift and duration if you want!! Make sure that you balance it and if you want to clean up the heads a bit, that would be good!! OH!!! The other thing is bronze guides!!

[ 03-31-2003: Message edited by: Gary Lloyd ]</p>
 
I wanted to bore it to get as much HP as I can, is it worth it? Will I get a worth while amount? See I have this extra engine and I just decided to redo it as a project, My B is still running and almost back on the road for the season. Any information on the cam would be great. Thanks for that link Chuck, the more things I know not to do the better.
 
Do the math. A .040 rebore is worth maybe 2, that's TWO, cubic inches. That alone will gain you possibly 3.0 horsepower. That would figure out to around $100 each. Save your money, lose 20 pounds and accomplish the same thing. By the way I think .040 is the largest stock bore without going way oversize and sleeving which might double your cost. A "hot" cam may create horsepower but mostly all it does for torque is move it around. The hotter the cam, the worse the low speed performance. Do you do most of your driving at 2000 rpm or 6000? Where do you want the best performance? Your biggest bang for the buck would be to mill the head for more compression and a modest port and polish. Best of luck, Bob

[ 04-02-2003: Message edited by: Bob Claffie ]</p>
 
Thanks for the advice, I will save my money from the bore and put it towards that five speed transmission I posted about before. I planned on milling the heads and thought about a port and polish, I have the standard SU carbs, would you recommend an up grade, a set of webbers would look nice.
 
I agree Webers look nice. However unless you have a Weber mechanic in the neighborhood skip it. They don't come set-up from the dealer and are a bear for the inexperienced. An alternative is to increase the richness of the needles in the standard SU's one step or so. Won't you rather spend $5.00 than $500?? I'll probably get a lot of grief on my motor comments but I am a cynic when it comes to trying to boost HP in street cars, I've seen too many with all the "right stuff", that ran worse after the modifications than before, (TR6's with triple webers are an example). Bob
 
Has anyone delt much with BritTek? I was just looking at there site and liked what I saw. They also said that they can set up my own custom rebuild kit. The prices didn't look that bad either for everything that is included in the kits. I was just curious if anyone has had any experiance with them, or the products they offer.
 
not without a great big cam and some serious head work. Regular SUs are more than adequate for 99% of all B motors. The easiest way to get some serious HP is to swap in a GM V6
 
I was planning on going with a big cam, some high compresion pistons, and head work. But out of curiosity tell me about this GM V6.....
 
most of what you need to know is here there are some other links on my website. Be ready to be blasted by purists, but anywhere between 140 to 200 HP from a stock motor?
 
I want to second the advice that you got about hot cams and Weber carburators on an MGB. I have a 1/2 race cam on my MGB (1978) and I wish I had my stock cam back in it. It has great reving power but terrible low end hill pulling power, (torque). A Weber down draft carburator does not improve performance over twin SU's. As a matter of fact a single Weber down draft under-carburates the MGB. A side draft Weber would be an improvement but it is much more expensive. Save your money and stick with well balanced and maintained SU twins. Porting and polishing valve ports is worth while. Best regards.
 
What type of cam is recomended? And lets say I go with the 1/2 race cam, although John advised against it. Does anyone know a safe amount to mill the head so as I have no problems with the valves and the pistons?? I though about the cross flow head....but that's a lot of money. I keep seeing it for about $1,400. That's a little more than I want to spend on one peice for this engine.
 
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