G'day guys. I am having problems with the tuning and general fuel acconomy of this engine. The setup is as follows: Standard red 186 block, yella terra head, standard 186 mech dizzy, standard glass mech fuel pump, WW stromberg with 55" jets, 5-speed supra box, 186s manifold and 2" extractors, 3.08 diff. I have gone to so many so called auto specialists in regards to the carby, tuning, electrics, and no real help to the running, the mech did say however that having a yella terra head on a standard 186 could have a large part to play with the problem, since the inlet and exhaust ports are bigger than usual. He also suggested fitting a cam to match the head and getting an elec dizzy out of a VH and a elect fuel pump could help?? I have been told that the 55" jets in carby should not effect the running or perfomance. The timing as is, is very high around 21 degrees which in turn makes is very expensive with fuel. At the momment the Donk uses around $5.oo fuel for 15km driving. Can anybody please tell me if what the Mech has suggested is right and will it work in regards to performance and economy/tuning. Are these modifications (cam)expensive $$$???? If you have any other ideas please don't hestitate, need to finally get to the bottom of this engine, it's driving me crazy.. Money to spend around $500-$600..
cheers fellas

Thanks jason, The engine has always been difficult to work with, I suspect the head. The timing is 21 degrees static. In melbourne sorry, but cheers for the help. To get it to run even kind of smooth , you have to advance so much???hmmmm.

jimbob

Yeah jason, the dizzy has been out so many times I have lost count. The donk is lined up TDC firing on one, then the dizzy inserted so rotor lines up with etched notch. The dizzy points staight out front , then adjusted to suit. The leads and coil are fa

Are you sure the timing mark on the balancer is correct? These have been known to be wrong.

I meant timing marks on the harmonic balancer, not the cam gears. Sometimes the balancer outer ring 'walks' on the rubber mount.

fit a new quality harmonic balancer, it is very common for the factory ones to fail when they get old.

To locate TDC accurately, screw a piston stop into #1 plug hole. Rotate engine carefully on the compression stroke until the piston contacts the stop. Mark the balancer at that point. Repeat rotating engine in reverse direction. The centre point between t

Hi Jimbob,

Do you know what specs he adjusted the rockers to?

Assuming your 186 still has a 186 head with adjustable rockers, you can do this:

Get engine to normal operating temperature.

Remove rocker cover.

Start engine and allow to idle.

Jimbob.

Vacuum leaks are easy. By yourself a $2 Bunnings spray bottle and fill it with water mixed with detergent. With the motor idling and stubling spray it around all the manifold joints. If it suddenly picks up after you've sprayed a joint that is

Thanks for all ya input guys, I have taken the car back to Mech and he said that timing was spot on after I re-marked balancer. Re-adjusted mixture on carby like ya said but still stumbling. sprayed with leak check but very hard to accetain if there i