Boosting.

[andybond]

Hi folks ,

I have a freshly built engine and turbo.

There appears to be no leaks - as I have a rock solid idle.

When I am anything upto 3/4 throttle and boosting it will boost fine , boost increases slowly and reaches 14psi and holds.

If I mash the throttle I get stoccato boost , spiking all over the shop - other times it settles and sounds like a f1 car when it is going down a pitlane.

I am thinking there is an issue with the carb or plugs. Anyone care to point me in a more specific direction ?

Got a rather annoying vibration that I can feel thru the seat of my pants and steering at 2200rpm. 2210 rpm its gone , but 2200rpm it goes mental. Any ideas ? I dont think the downpipe is catching on the downpipe as the second i dip the clutch the vibration goes.

Again tips are appreciated.


Andy

[Brigsy]

Vibration could be a duff shaft sir..i need to have a look at this carb for you that will prob sort these isues out.

[andybond]

Fair play.

I didnt want to bug you via SMS - you have been a legend so far .. so I thought I would ask on here :)

[andybond]

Its getting worse :(

If i have a feathered throttle the car appears to hesitate slightly. It keeps going but its rough.

Under anything greater than 3500rpm with the pedal to the carpet it pulls initially and then misfires. Unless in 5th , where it happens at 4500 rpm.

Any suggestions what I should be looking for ?

[andybond]

Hi folks - need some more pointers.

I have checked and double checked the dizzy.

Got the engine to TDC by using the markings on the bell housing and using the TDC mark on the fly.

To double check i removed plug no1 ( closest to fly ) and put a small flat smooth screwdriver in there and checked that it was TDC as the alignment marks can sometimes be out.

I aligned the dizzy gear in so that it pointed to 1200 and 1800 and stuck all the jazz back in and ran it.

Started on the button. Reved upto 3000 then it gives the mother of all misfires and sounds like a shotgun.

The carb appears to be thowing fuel in via the main jet as it should.

My plugs are a little ( lot ! ) sooty. I guess this is due to a weak spark ?

What next ?

remove the plugs , clean them up and re gap ? 0.6mm ?

This is a fresh set of plugs BTW- they are the NGK B8Xxx ( cant remember exactly)

I also have some new HT leads on the way JIC mine are U/S

Car runs fine under load until the 3000 rpm mark.

Tips or suggestions. Or even a friendly arsonist required.

[andybond]

Cured this last night with the help of brigsy giving me some advice.

I redid the dizzy timing bang on what the haynes said but it still missed. Changed everything ( dizzy shaft , spindle , rotor , cap , ht leads ) but still missed.

Undid the clamping bolt that holds the dizzy in place and took the spindle out and put it back in the "wrong" way around. IE where the part that is normally bolted down was facing the flywheel side.

Started the car up and moved it slowly until I got a rock solid idle and no misfire. Turned engine off and clamped it down.

Took it out for a boost and it was fine.

Happy Days.

[James5]

Andy that is good news matey so it was about 180 degrees out then fecking Haynes book of lies

[andybond]

Andy that is good news matey so it was about 180 degrees out then fecking Haynes book of lies

Pulls like a train now. A train weeping oil , but its good never the less

[andybond]

Playing this game again.

Got another head on now , after the last one failed.

I cannot seem to get the timing right.

Correct way around
Boosts fine in 1st / 2nd , 3rd misses at 3500 + under full load

Spin the dizzy gear 180deg out
unstable idle.

rotate it back towards original position in small increments means stabler idle but cant find the sweet spot of boost + idle.

WTF ? Redo it all again ?