Input on '68 MGB engine work?

Hi. My father is restoring a 1968 MGBGT in Albuquerque, and would appreciate any suggestions that folks might have on what to do with the engine. Here's some background info on the engine and his objectives;

He's looking for the best possible balance between drivability, good torque and mileage mostly in the 3000 to 4500 or 5000rpm range. Primary operation will be in the 6000-7000 ft altitude range. This will just be a street driven car. Cost IS an object.

The carbs were rebuilt by Joe Curto and the distributor by Advanced Distributors given the above performance objectives.

The engine is a de-smogged 1968 18GF presumably with a stock cam. Compression is 135, 135, 140, 139 at 6000ft elevation. Note this is after he retorqued the head, so it appears well within tolerances now. Don't know if it has hardened seats installed or not, but he has discovered one bent push rod. Further investigation is clearly needed.

Does anyone have experience, or know someone or a shop with experience with building engines of this nature? If the head ends up needing work anyway, any input on the tradeoffs (flexible performance / fuel economy / cost) of aftermarket heads (which one?), port work, cams, etc? Again, he's not looking for a race car but rather an engine which will comfortably get up the hills of Albuquerque and be fun on any mountain excursions in NM or CO.

Thanks in advance!

John Twist university motors youtube vid link

Join mgexperience link

A great resource in ABQ is the BAOA (british automobile owners association). website is: http://www.nmia.com/~bsavage/baoa/

There are several B-GT owners (including myself) looking for/doing engine work.

Cheers, Jake

Thanks for the comments guys. I'll pass them along. I know my dad has actually met John Twist at a meet in CO last year, and has checked out some of his online tutorials. Don't know about mgexperience or BAOA though.

Scott

Is that engine burning a lot of oil or does it have low oil pressure? Given the compression numbers, it doesn't look like it needs a rebuild to me. MGBs with 8:1 motors usually have numbers around 125, while the higher compression engines are usually around 140-175. When the numbers are around 175, they tend to give more trouble with pinging unless they have a bigger cam. I talk a lot of my customers out of rebuilds and I guess that's what I'm doing here. With my customers, they usually think they need a rebuild because it isn't running well. A proper distributor curve and a proper carb rebuild is almost always the answer. Looks like you dad's already done that.

Replacing a bent pushrod is easy--of course you need to find out why it bent.

If he's looking for more performance, a good alternative to a whole rebuild is pulling the head and getting it ported. That's worth a bit of mid-range torgue and about 10HP up high. If he bumps the CR just a little and adds a cam, he'll get a bit more. I wrote a story in CMS about doing this to a 1973 MGB/GT a few years back. We picked up about 15HP at the wheels and took 3 seconds off the 0-60 time on that car and it's a popular formula for our customers.

--Carl www.eclecticmotorworks.com

I agree with Carl - those numbers look pretty good for that motor.

More power = two choices. Either conventional tuning, which really means headwork and more cam/compression, or the bolt on solution - shell out the bucks for a Moss supercharger and have done with it.

I'd suggest the latter for your proposed use for the car.

Thanks for the suggestions. I'm passing them on to my father. Regarding Carl's question about burning oil, we really don't know yet. The last several years have been spent getting the rest of the car refreshed. It just started and was driven down the street for the first time in July, sans front wings, bonnet, and most of the interior. He said that the oil pressure looked good, after fixing the regulator.

Appreciate you all taking the time to reply.

Scott