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The obvious answer is a before and after test with a dyno/rolling road, but there are pitfalls here for the unwary - your car will be stationary rather than moving through the air, though a blower is usually directed at the radiator/engine bay. The bonnet will also be open rather than closed, so airflow into your cold air intake might not be the same. These changes in operating conditions can all affect the HP, though if you endeavour to keep the same conditions, you might pick up a difference due to the new intake. On the other hand, if... MORE
Good idea. It's switchable (two rubber plugs) from hot to cold air, so I can do a side-by-side. I'll give it a try on some good hot day. I think it pretty much has to be done on a real road to get the full effect of under bonnet vz wheel well temps. "joe blxfstz" 37491... MORE
There was some discussion about insulating exhaust manifolds (headers, extractors, etc) and about keeping heat from the carbs. I wondered about that, did a little reading, and a little PV=nRT stuff, and it looks like a cool air supply to the carbs might add a few HP. Maybe. Anyway, not being one to spend money extravagantly (the wife doesn't agree BTW), I put together a $10 cool air intake. It's easier to see than explain, so take a peek at the cool air photos. Now, the question is - if it adds, say 3 or 4 HP, how on... MORE
Todays a good day! The Blue Angels are in town for an air show this weekend, at this moment they are practicing outside of my office window, hope the roof stays on! Hope my hearing comes back soon. Later Rick Bender "Rick Bender" 37483... MORE
G'day Phil It is important that the mounting bolts remain loose, and the bushes able to rotate, until you have the car back on the ground. Then tighten the bolts. In operation, the bush doesn't rotate, rather the rubber flexes. Under load on the ground is the "neutral" position. If you tighten it when the car is in the air, the bush will already be under stress when you drop the car to the ground, and it will not survive many miles. This applies to all suspension bushes, both front and rear, on all model Sprites and Midgets. avagoodday... MORE
G'day all Let's start with a definition. Those non-standard tubular pipes that bolt onto your cylinder head to let the exhaust gas out, and eventually join into one "collector" for the exhaust pipe, are called "extractors" or in some languages "headers". "Exhaust" includes these plus everything down the line, past the muffler to the chrome tip on the tail pipe. I guess we are talking here about insulating the extractors, not the entire exhaust system. We run in all our engines on a calibrated engine dyno. It lives in a 10ft x 15ft brick room with a huge fan... MORE
Joe and others.. I understand that keeping the air intake cooler is definatly a good thing. But as I was saying I have heard that keeping the exhaust manifold hot, insulated is a good thing, independant of the fact it helps keep the engine area cooler. Mainly because of gas flow is better at hot temperatures? Or may be its because changing the density of the gas, as it cools down restricts the flow? "gav_newman" 37447... MORE
How much more power do you want than you can get from a well tuned 5 port head? Or is it as much for appearance's sake? David PS welcome to the group! "David Jacobs" 37442... MORE
Keeping intake air cooler is a good thing in the summer. Keeping the ex manifold hotter is a bad thing (unless, maybe, if you're running a turbo). "joe blxfstz" 37444... MORE
I have heard insulating the exhaust manifold can improve performance significantly. Both from keeping the exhaust hotter for longer and keeping the incoming air cooler. Have many other people done it? I have a unmodified (apart from an oil cooler) 1500cc Midget, would it improve my Horse power and or MPG? I ask cause I have been reading the Vizzard book and it does not seem to mention any benefitt from keeping the exhaust hotter. "gav_newman" 37423... MORE
New to the Yahoo group, hello and thanks in advance... Has anyone out there had experience with 7 or 8 port cylinder heads? Vizard's guide has a whole 3 paragraphs on the subject, Stapleton has one! I came across an old issue of Retro Cars (May '04) that reviewed A series engine tuning and and turned me onto this option. I've gone to Mini-Spares UK website and priced the unit ($$$- but cheaper than the K-series engine swap, which would be way too hard to do living Stateside). I've viewed Bill Richards Racing website and read about how he... MORE
Another thought on the roll bar is its possible benefit in a T-bone collision. It would offer at least a little more protection from someone who crashes a stop sign and nails you in the side. I have yet to see a spridget with side air bags. Nelson "Nelson Wittstock" 37391... MORE
You know, one is for engine timming and the other is for setting up the air conditioning, but I can't remember which is which. One you can reve the engine by pushing the throtle, and the other you can't, it coughs and dies. Bob, Troutdale, OR "Robert Webb" 37346... MORE
G'day Jeremy Your car probably had a PVC (Positive Crankcase Ventillation) valve on the inlet manifold, connected via a rubber hose to the engine breather. When you had your foot off the throttle, the partial vacuum in the inlet manifold helped to reduce the pressure in the sump, thus (in theory if seldom in practice) minimising oil leaks out of the rear main bearing. This PCV valve was later deleted, and the hose from the engine breather went to a plastic Y-piece and then via two short rubber tubes to these pipes on the carbies. You have two options.... MORE
Jeremy... these "tubes" feed graduated (specifically sized) orifices through which crankase gasses are fed into the combustion process in a measured amount, off the "flame arrestor/oil vapor separator (through appropriate hoses and plastic "T" fit ting) mounted on the timing chain cover. These make up the "exit" or "exhaust" side of the PCV system on engines so equipped, the "inlet" side of the equation being a filtered plastic oil filler cap on the "early" cars or a feed tube into the valve cover (again, through a "graduated orifice) from the charcoal cannister on later emissions vehicles equipped with closed... MORE
"we think turbocharging is the way forward" Most likely is, if someone can come up with a "variable" waste gate for both low and high end and a nice, "flat" torque curve.... and have no fear....somebody will!! :):) And of course, intercooling of the charge is a real nice thing to have for obvious reasons. The great thing with supercharging is "immediate" low/mid-range torque for the basically stock street car....in the order of a 40% with a "gentle" (on the motor) 6psi. IOW, (high) revs are not required, which for our 3 main bearing applications is a blessing. A... MORE
Yep!! There you are! And at the going price considering the MiniMania/Hans Pedersen kits. More low/mid-range torque for street fun. Having driven a stock '67 1275 Spridget using 6psi boost, I can honestly say it is worth the 3k assuming you are go ing to keep the car. Probably one of the most worthwhile upgrades besides the Datsun 5 speed for those who want true "quick". 6psi is the lowest amount of "effective" boost (torque/heat) without unduly loading stock parts providing you don't over-rev the motor and resist the urge to constantly take it to the redline, bearing in... MORE
I have just replaced the head gasket on my 1500cc Midget, so I was quite chuffed to say the least when it turned over after only a few attempts. However I was not so happy when I noticed at lot of petrol was coming from the bottom of the rear float. I have twin SU carbs. I know that this was dripping a tiny amout of petrol before I changed the gasket but it is now flooding out. I realise extra fuel will have got in while I was turing the engine over to set the rocker gaps, but... MORE
WEBER DCOE "air" screws They are not air screws. They are volume screws, the mixture for the idle circuit having been pre-set by your choice of idle (air/fuel combo) jet. 1.5 turns "out" is merely a starting point for setting. You may find your particular choice of idle jet runs best at only 1 turn out or even less. If you cannot find a setting which will work, you will have to change the idle jet for a less rich (weaker) one which may either consist of a smaller fuel aperature OR same fuel aperature with a larger air... MORE
Does anybody know about setting the (2) air screws on a Weber dcoe sidedraft carb on my '75 Midget 1500, it's running rich, i put in new plugs & wires, i aqquired the car with the carb. on it. the screws are 1 1/2 turn out. It has headers and has been de-smogged. It has a points distributer also. Also i took the spedo cable off because the neadle was 'hopping' and oiled it, now it doesn't work, any idea?? Thank you. "hdsteveg" 37228... MORE
G'day all The MGB heat shield will work, after you cut it in half, but it might not be easy to find one that the owner will part with. They might prefer to sell the manifold, carbies, heat shield etc as a complete unit. Mini Cooper S had 1.5" SUs as an option, and their heat shields were actually two pieces with a bridge joining them that also held the return springs. You could use the appropriate side of this set-up if only you could find them! I can only supply them new, as a pair, for around $35... MORE
There is a poly-block that goes between intake manifold and carb prior to the heat shield/carb. And I recall there was (asbestos-type) insulation on the shield of my PO'd MGA's. I do not recall this on my later post-60/70 Spridgets or MGB's. Not on my Frog restored by PO, either. Of course, any Home Despot will carry something which can be used along wit h modern adhesives that will do the trick. Or heat reflective paint/coating. Beyond higher engine compartment temps in warmer weather which translate into higher induction air temps and gener ally less peppy performance under these... MORE
The heat shields are just sheet metal with no insulation. They block some radiated heat from reaching the carbs, and also deflect hot air so they work okay. Certainly not a bad idea to insulate, though. Oh, the also keep leaking fuel from dripping directly on the hot exh manifold. "joe blxfstz" 37172... MORE
The easiest way is to take a kitchen meat thermometer, and take off the radiator cap, start car and when the temp gage needle starts to go up, put meat (or candy)(or whatever) thermometer in top of radiator and watch the temp on both. They should be close to the same. You can take a sheet of newspaper and cover the radiator to block the air from the fan to allow it to start to get close to 212 degrees as the upper end of the test. I think this is easier than removing the gage and sender and... MORE
The gauge can be calibrated Jim for zero and span. I used a pot of boiling water for the high end, just place the temp bulb in it. I keep it boiling with the propane torch to ensure 212 deg. The needle can be removed from the gauge and replaced in the correct place if need be. If the span is out the small linkage within the gauge can be tweaked very lightly to make a difference. I used fresh air for the low end point. Duncan "Duncan Sinclair" 37159... MORE
