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Mickey Richaud

Mickey Richaud

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All this has been covered ad nauseum in previous threads, but am looking for advice. I'm at the point where I'm tearing down the motor in my '73 MGB, and will be sending the block, crank, etc. off to the machine shop for any work necessary. I want to build this up for reliability as well as a bit more performance. The car will be used as a driver, with the occasional car show (not meant to compete). One thing I read about is replacing the single row timing chain with the earlier double row. Will that clear the timing chain cover? Any other concerns?

Since I'm doing the work, I plan to put the labor costs into performance parts (cam, pistons, etc.). So, my question is, What would you do?
 
I have a '72B and according to the catalogs I have seen, it was supposed to have a single chain. Mine has a double chain, cam sprocket, and crank shaft sprocket and there should be no problem converting yours.
Also I strongly recomend new oversized pistons and overbore on any rebuild whether or not you are going to high performance. I went .020 overbore on mine and put the high compression factory pistons in mine and have used no oil since and that was 1987. Every car I have rebuilt proir to that by just honeing and replacing the rings, has used oil.
I stayed with the stock cam mainly because I didn't want to lose the bottom end (lower RPM) power. Also, I do an occasional auto cross and a stronger cam would put me in the race class where I wouldn't stand a chance without going all the way to full race modifications.
If you are using the car as a daily driver in traffic I wouldn't recomend a long duration cam because it would be very unpleasant in traffic. Pick something longer than the stock but not the longest duration. The longest would be more suitable for all out racing.
I don't want to get too long here so I'll leave some for the other guys and mods they have done.
Ignition, distributor curve adj, carburation, exhaust etc.
 
I disagree with the above. I rebuilt my "B" engine (50K), with only a hone job and the original pistons. Uses no oil between 5K changes nor does it leak! As far as modifications go unless you are prepared to spend several thousand dollars don't even bother. All a different camshaft will do is move the HP and torque around and make the car less driveable. For a cheap, slight improvement, I would suggest a stock pre '71 cam and a set of HS 4 carbs. Cam has a little more poop and the carbs are more adjustable. Most "go fast" parts are designed to work best above 3000 RPM or more. If you ever see a dyno comparison of a stock engine vs a modified engine, the big improvements are 5k or higher and our antique engines were not designed to buzz that high on a consistent basis. Typical waste of money parts are headers (any place except at the track). Sorry for the rant but have seen too many good running stock motors ruined by "improvements". Bob PS: DO consider having the engine balanced regardless of whatever changes you make. That will make it run smoother and live longer.

[ 07-12-2003: Message edited by: Bob Claffie ]</p>
 
I knew I'd get differing opinions! But thanks, guys. I pulled the crank, camshaft and pistons, and found them in fantastic shape. I knew that the previous owner had rebuilt the motor and never started it, but wanted to check. Rod and main bearings are standard; cam bearings look new. Inside was clean, but one of the main bearing's oil passage was plugged with crud. Will be sending everything to the machine shop to verify tolerances, boil out the block, and had already planned to balance everything. Based on the condition of the pistons, will probably re-ring them and let it go at that. Any other opinions regarding overbores?

I like the idea of using HS-4's. I've got 6's in the TR3, and they are easy to work with. If I do go with .020 pistons, are the 6's better suited?

I'm not too concerned with over-revving. The car has overdrive, and will be driven responsibly (yeah, right!), but do want a bit more response out of it. But not at the sacrifice of engine life. So, any other ideas?
 
Like you said, Mickey, you will get many different opinions here that reflect the individuals personal experience. I think you are on the right track as far as the decision about the pistons VS reringing is concerned. The ultimate decision is yours based on the info the machine shop gives you. Because every engine has seen different patterns of driving and the wear can be different in each engine.

My experiences have been with engines that have seen a lot of wear. There are tolerances that the machine shop is best equiped to measure and advise you. If an engine has more than .010" of wear, they will probably advise you to rebore to the next size up. Also there is a tolerance on how much "egg shape" a cylinder can have. Ask the machine shop about this and the general opinion I have heard over the years is no more than .003"

Next, don't be afraid to modify a car to your particular needs or desires, like you are here, by asking for opinions by those that have done it before and YOU judge by the opinions you get back, what you should do. There are many ways to make your car more drivable that you will have to ultimately decide what you want.

[ 07-13-2003: Message edited by: mrbassman ]</p>
 
Item 1. If you boil out the block that destroys the cam bearings so be prepared to replace them. Item 2. If you're going to the expense of reboring and new pistons don't stop at .02 get something for your money and go .040 (you are only going to do this once aren't you?) Item 3. I think 6's would be too big for 1800 CC's, with HS 4's you can always go up a step or two richer needles. Be interesting watching your progress, keep the thread alive. Bob
 
Thanks, Bob. As I mentioned, the motor had been rebuilt, but never started. Can't understand why, but the prev. owner didn't paint the block, so the outside is coated with a lovely patina of rust! Inside looks great, but will send it off for cleaning anyway. Had planned to replace cam bearings, along with all others after everything is measured.

By going .040 over on the pistons, any ideas as to resulting displacement? Also, the cover article in Moss' latest magazine mentioned stroking along with oversize pistons. Comments on that?

Am putting the project on the shelf for a couple of weeks while we travel to Honduras. When we get back, it's off to the machine shop.
 
Sure would be handy to know what your budget for engine mods is. Just a rebore and pistons, you'e likely looking at $400. For a stroker kit, which means a new crankshaft, will be over $300. And of course, you will need a new crossflow head at $1600 and dual webers DCOE's for another $1200. Where do you draw the line? After all the engine changes you HAVE to beef up the brakes and naturally the suspension will be the weak link next. Just think, when your all done the "B" will be almost as good as a stock 1990 Miata, but with character. If you come back to this thread and tell everyone you have X amount of dollars to throw at this project you will probably get some good advice but at this point it is all conjecture. Bob
 
Mickey, you don't know me from Adam. I have a shop that restores, and repairs British, and Italian cars. I have built full race motors for MG's. For one thing the difference in 20 over and 40 over is nothing as far as HP. Ten thosands is about the thickness of a sheet of note book paper.Secondly unless you are going to do some major mods to the engine the HS6 SU's are too much carburation. By major mods. I mean port, and polish, rimflow antireversion valves,high ratio roller rockers, billet steel cam, chilled Iron lighten lifters, titanium push rods, lighten and polished rods, ajustable cam gear,stress relieved bottomend, blue printed engine, and so on. None of these things will make a stronge motor on their own. It take all of the in balance with each other. I have built very streetable MG motors with 135+ HP, but it get real expensive quick.
 
LISTEN TO TOM!
 
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Tom is the MAN when it comes to high hp MG engines, if you want to go fast just send him an engine and a blank check. He probably even has an engine he could start with
 
&, since Tom's too much the Southern gentleman to post a link to his site; &, since I've been admonished by some for not being enough of a Southern gentleman, I'll take advantage of my Rhett Butler reputation & post it....if you want to see what Tom's all about, go to https://www.importandsports.com
 
Tom (Adam) -

Thanks for the advice. I've pulled everything apart, and all looks very good. I'm in the process of looking for a machine shop to verify tolerances and condition of everything, then will begin reassembly. Based on what I've read here, will more than likely go back stock, perhaps with balancing, porting & polishing, but not much else. Had already decided to stick with the stock SU's. All I need now is the time to do all this, as well as the cash!
 
Mickey....as close as you are to Memphis, it'd be worth your while to take off work one day & drive over to meet Tom & see his operation....I'm planning a trip up in the next few days (a Wed or Fri)...maybe we can both converge on him & talk him out of lunch!
 
Mickey, you have made the right decission. I would have the engine balanced, but having it ported would be a waste of money on a stock engine. Unless you cam it up and put wasted stem valves in your not going to notice any improvement. Matter of fact you may loose you bottomend power.
 
Tom....Mickey & I are planning a road trip to your place...lunch?
 
With porting, you do lose a little bit of bottom end, (it is kind of like putting 2.02s in a SB chevy) but everything I have read and heard locally, you do gain a fair bit on the top end with a cam. I am sure that you would gain a lot more with wasted valves!! I just had my head ported and polished, but I only have 250 miles on it, but it does feel different!! I haven't taken it over 3500 yet, so I really can't answer honestly!! Of course the last one 'self destructed' at about 4000 miles, but it did run strong while it lasted!! It only cost $240 cdn or about $160 usd, so I figger nothing ventured, nothing gained!! Anyway, let me wish you good luck, and I agree, balancing is a must!!
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Great Tony, I look foward to it. Just don't come om Mon. or Fri. I take off om Mon. and Tim Fri. So Fri. I'm there by myself and can't leave. About the souther gentelman. I wish I could except the complament, but if I wasn't so computer stupid I would post My web site and pic of my cars.
 
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