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MG MGB Technical - Car wont start after rebuild help!!!!

I purchased a fast road KB cam from Brittek in a engine rebuild kit. My question is the car will not start after rebuild. I set the points, timing is close not sure since i cant get it to run. Cam is installed exactly how a stock one would be. The dots on the sprockets line up when rotated. Is this correct??
The car has spark. I have installed the stock dist. by tdc and took out the sprocket and made sure that it was at 1 oclock. Can you guys help me out? I am at a lose. Thinking maybe the cam has to be degreed or something?
The carbs are getting fuel not sure if they are operating right but before i tore it down all work fine and ran good. Didnt touch the carbs just installed them back on.

thanks guys for any input
matt kaser

Matt. Yes, a special grind cam should be degreed in. Many are re-grinds and degreeing in the cam ensures that it is operating correctly. None of this, however, should affect the ability of the car to start when the dimples have been aligned on the cam and crankshaft sprockets. It only affects how well the engine will run.

Do you have a dynamic timing light? If so, hook it up and have an assistant turn the engine over as you watch the light. Turn the dizzy until it is somewhere near 10 deg BTDC and the car should start. Then, you can set the correct timing as per the factory specs or the specs supplied with the cam. Les
Les Bengtson

take a compression check this will let you know if you made a big mistake on you rebuild assembly- RIC
ric

Matt,

Are you getting any firing at all? Sputtering or missfire? If you are getting absolutely no ignition whatsoever check to see if your points and plugs are getting a spark as it maybe something electrical which is simple to set right. Alternately, have you checked that you are on the No. 1 compression stroke as the dist. arm comes around into position (always possible to get this 180 degrees off).

Cliff
Cliff Maddox

If you can't time it any other way the unwarranted, cheap and dirty method is to unscrew plug 1, reconnect the HT lead and hold the plug against the block whilst turning the crank pulley. Look for the spark. You want it at about 10* BTDC. To avoid hazards, disconnect the other leads to stop the engine starting accidentally and wear rubber gloves. As Cliff says, check that both valves are closed on 1 when it sparks. If not something is way out. The other thing to check is the plug gaps (at least it was on mine).
Steve Postins

Start from first principles. Do the plugs smell of fuel after a period of cranking (OK)? Soaked (flooded)? Or no fuel smell (no fuel)? By clipping a timing light onto the king lead and each plug lead is it flashing? Have you got the firing order correct i.e. 1342 anti-clockwise? Is the rotor pointing at No.1 when it is on its compression stroke i.e. blows your thumb off the plug hole as you turn the crank? Variation in the cam will affect performance but it would have to be way out to stop it running altogether. I seem to remember that with the dots aligned and next to each that is *NOT* TDC on the firing stroke for No.1 but something else. The Workshop manual says for the dots to be closest to each other "Set the crankshaft with *its keyway* (my emphasis) at TDC and the camshaft with its keyway at approximately 1 o'clock as viewed from the front". But with only one keyway and one dot on each wheel and shaft is it even possible to get it wrong?
Paul Hunt

Paul is correct. With the dots alinged next to one another, number four is firing.
Leland Bradley

Is it possible he installed his distributor drive gear 180 degrees out?

Robert
Robert Rushing

I rebuilt a '74 and made this blunder - had the dist off by one tooth. Been a while but it was maybe 20 degrees out. No start. I'd double check that the rotor is pointing to the no. 1 terminal with piston #1 at TDC. Good luck
Phil Collura

Thanks guys,

Here is where we are at. Points are correct, plugs are sparking, and them seem to have fuel on them. WE put the crank pulley at TDC and then installed the dist with arm at #1 spot. We are going to try and static time it. Think maybe either the gear might be installed wrong or the dist something wrong not sure.

How u install the dist gear correctly? Slot at 1 oclock?

thanks
matt kaser

Did you check the compression yet? RIC
Ric

The drive gear (inside the block) can be installed in as many positions as there are teeth on the gear. But the distributor drive dog can only be installed to the gear and pushed fully home (note) in one position. However if the distributor has been dismantled that can be reassembled 180 degrees out. The only way you can check if it correct is to get No.1 piston at TDC on its firing stroke and see where the rotor is pointing, which should be about 1 o'clock. If it is wrong you can reposition the drive gear, or move the leads round the cap to suit.
Paul Hunt

Stupid idea, but.... Check *all four* plugs for dampness after cranking. Had this on a midget once, plenty of fuel showing at #1, timing OK static, spark at right time, would not fire to save its life. Finally pulled all four plugs to reveal that #3 and #4 were completely dry.
Stuck needle valve on the rear carb........
T J C Cuthill

This thread was discussed between 14/05/2003 and 16/05/2003

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