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Mr Zappa, You should have a Zenith cd150 carb installed on your car if it is stll as originally equipped. These carbs have been trouble since the day they were installed new and only get worse as time goes on. As for the fuel leak. Look real close at the rubber hose where it attatchs to the carb body. Small hairline cracks frequently are found causing fuel to weep. Have someone crank it over and you watch right here for where the leak appears. Another possibilty is the auto choke (if installed) can be a pain in the a$$.... MORE

Just started up my '77 Midget to let it run for a while (35 degrees F and started like normal) when I noticed a heavy gas smell. I looked for a leak and found gas coming from under the carborator in a small, steady stream (running onto the heat shield and dripping on the exhaust system). The gas line looked fine coming into the carborator. I'm pretty new to engine repair, so I would appreciate any suggestions on what to do. Do I need a new carborator, or can they be rebuilt (by someone new to it)? Thanks. "tzappa"... MORE

oh right, I get you. As you said yourself in another post, it's down to a combination of the total package and depends how keen Alan is to get that last few horsepower. The standard manifold will work, but the higher the potential HP output of the engine, the greater will be the proportional loss. David "David Jacobs" 27947... MORE

David I mean in terms of the 'state of tune' of the engine. Did the MG Metro not have a different inlet manifold, cylinder head, bigger inlet and exhaust valves and carbs etc ? Nigel "amukdigiphoto" 27945... MORE

David BIG difference between the MG Metro 1275 and the Spridget 1275 though hmm? Nigel "amukdigiphoto" 27943... MORE

Alan A good old 'how long is a piece of string question' ! I think you need to look upon this as an upgrade 'component' within a group of upgrades who's sum will exceed that of its individual components. ie it depends a lot on what else you're doing to the engine and what it is that you want out of it - more power? better economy etc. Used in isolation you'll only be getting about 4 or 5 extra hp at rev ranges above 3.5, 4k. Nigel "amukdigiphoto" 27941... MORE

Hi, Alan... With respect to correctly sized LCB.... for the stock and/or short cammed engine (with largest Mickey D's in one hand and Vizard's book in the other) in a word NO, not in and of itself with respect to the stock engine, or even as part of a free flow system, unless you are cruising the highways at 70+ most of the time. For a trifle more power... The short 3-1 is better for fuel economy below the rpms associated with tooling around town and driving applications wherein rpm's associated with the above paragraph aren't likely to be... MORE

David If its any help the the 1098 10CC engines used the same part number manifold as the early 12CE, 12DA1275 engines (12G420) up to GAN5 139772 from GAN5 139773 the part number changed to 12G1581, athough the manifolds look identical, the only main difference is the introduction of a flange on the manifold to the downpipe. So the answer to your question is yes it will fit on a 1098 with no change in performance. My 1971 1275, also had a tubular manifold fitted, and whilst it was a pretty tight fit, nothing was altered to make it... MORE

Don't know, but I do know my 1275 engine in he '59 has a three branch exhaust manifold on it that was originally on a 948! Stewart "Ford Prefect" 27925... MORE

By now it should be obvious that I have a few days off and am spending them in the workshop, hence another quick question. Are 1098 and 1275 exhaust manifolds identical or is the 1275 version a little larger internally, and if the 1275 is a little larger internally would it fit on a 1098 and what effect would it have on performance? The reason I ask is that my project (65 Sprite ) has one of those performance enhancing three branch manifolds unfortunately the previous owner has hacked a lump out of one of the front chassis legs... MORE

David Regarding 'practicing' your welding skills, I agree 100% with you, I've just been through this process and I know where you're coming from. I also went through the 'thought' process of repairing my own ones, but for the reasons we've both realised - it just isnt worth it. I also made up a number of my own repair sections, for various reasons, but usually because I didn't want to hold up progress while I ordered the section and waited for it to arrive. One notable one was the passenger side lower A post hinge mounting. I used the... MORE

Dave I also had to repair that area on my car recently, including putting in a new 'chassis mounting tube' to replace the original one that a bolt had seized in, and as they're high tensile steel, I could not drill it out. I simply cut out the mounting tube and refitted a new one - much easier. I also debated on whether to repair my old 'riser brackets', but felt on balance, bearing in mind the amount of work involved, it would be easier to just buy new ones, which I did. "amukdigiphoto" 27911... MORE

Hi Robert. Actually, if you read my post you will see that we are in full agreement. We both state the source of the increased pressure as coming past the pistons, rather than the volume displaced by the pistons which is balanced out. And we both refer to the oil leak problem that ensues. Interesting stuff about filling a 2-stroke crankcase. This was effectively the best way of increasing the compression ratios on a 2 stroke. I never went as far as you with using bondo, but I do remember there were a number of firms selling crank-case fillers... MORE

I agreed to that. See not all the air/fuel mixture get combusted or blow out the exuast. Some of the got by the piston ring gap or right between the rings and cylinderwall (bad) inturn increase the crankcase pressure. One of the few ways the pressure can be relieve is through the PCV and if that thing is clog, the oil seal at the crankshaft will be the one that take toll. Pat "Pat S." 27912... MORE

You are correct, in a perfect world, the pressure would balance out to be zero, but a little pressure sneaks past the rings, the valve guides, etc and any positive pressure pushes oil out the rear seal. Interesting side tangent when talking about two cycle engines. When I was a 16 year old kid, I worked for a marine place and we built racing Johnson outboard motors. Roy Rogers,( the great cowboy movie star) had us build his engines. Twin Johnson 35's for off shore racing. My boss and I drilled the crankcase full of holes and inserted one... MORE

When one pair of pistons is descending, the other pair is rising so the volume of the crankcase is not altered by the pistons. Presurisation of the crankcase is caused by blow-by at the pistons, allowing compressed gas from above the pistons to transfer into the sump, creating an increased pressure there. When what you wanyt is a decrease of crankcase pressure to stop oil being forced out past the so called "scroll seal". I think that 9in a 2-stroke, the crank is sealed between adjacent cylinders so each piston has its own crank case space through which the... MORE

In a 4 cylinder engine, two of the pistons are rising while the other two are falling so the net volume change in the crankcase should always be zero but it does suck in air when everything's off and cooling down. David "David Jacobs" 27896... MORE

I should ask the guys at work, but I'm on holiday 'til the 5th Jan. so I'll ask you guys. Because of the action of the rods and pistons, doesn't the sump / crankcase, suck as well as blow? I know two strokes use this phenomena to suck in petroil / air mixture then transfer it by blowing it to the head ready for combustion. Alan BTW - Isn't it noticible that the number of posts have reduced during the holiday, which leads me to think that most group members use their PC at work to correspond. I bet... MORE

Lessee... The combustion process sucks, squeezes, bangs and blows...and... yep...the crankcase sucks and blows... definitely a two-way street! :) Cap'n. Bob '60 :{) PilotRob@... 27897... MORE

how else would you reduce the crankcase pressure to atmospheric or below? Regards David "David Jacobs" 27889... MORE

BECKERS states (in part).. "....it lowers fuel octane anyway" Yeah, this is true and a tough one to call (except in a high compression motor or when higher octanes are available at reasonable cost) against crankcase evacuation of vapors/pressures with respect to oil being forced passed seals or out the rear scroll "seal". But it's basically why I run "vented" instead of "evacuated", the thought of introducing oil (in any amount) into the combustion process "going against the grain" personally, though there are cases (Judson and to a lesser extent, Shorrocks applications) where this comes with the territory so... MORE

Paul.... Assuming you are using the normal intake manifold mounted stock PCV valve, most likely the rubber diaphragm is "weak"....we all know what happens to rubber exposed to ozone (air) either sitting on a shelf in a parts wharehouse or mounted on an engine which has sat for a long period of time. The high idle along with intermitten excessive "smoking" is almost a dead giveaway. Check that hose between the flame arrester and the PCV valve as well. Rubber develops "hairline" cracks with age. Like most rubber, it lasts longer when used (not abused) while exposed to whatever... MORE

Thanks to all the "start-up" advice, the initial run-in went without a hitch. But a strange problem cropped up. Engine is a fresh high compression 1275 with PCV only. It would run very well for the first few minutes, and then start to belch smoke the likes of which few could imagine. It would do this for a couple minutes, then run normal again. Also, I could not get it to idle below 1200 rpm despite the fact that the carbs were fresh and were properly set up. With throttles CLOSED it still idled at about 1200. After doing... MORE

Stewart It was more to do with the need to meet 'low speed impact regulations' that the 'energy absorbing' bumpers were introduced for the American market, rather than the 'precise' height of the bumpers. It had to pass certain front and rear impact regulations, and that in turn dictated the height of the bumpers and the subsequent raising of ride height. These were 'safety' introductions, introduced soley to pass the new regulations. Likewise the 1500 engine from the Spitfire which would be far easier to modify to meet the 'emission regulations' coming into force than the older A series.... MORE

G'day Peter C I pack the oil pump with black moly grease (Molybdenum Disulphide). The oil picks up straight away, the moly does no harm at all to the bearings etc, and it all gets dumped out 30 minutes later anyway. Yes, I know you can prime the pump through the hole in the left rear corner, but my thumb get sore pushin down the plunger on that oil can. Now here's another way of priming the pump. You know where the oil line goes into the rear of the block on the right hand side? Well directly below... MORE