No wonder this was happening

[G_loomis]

Firstly let me make it clear that I have a little mechanical knowledge, but by no means am I an expert...

For a while now my HJ60 has been making a tappy noise on acceleration...I have been thinking of booking it in with Sean Calcino when he gets back from the Outback. But I was under the hood just now (still got dirty fingers) and realised what it could be...

Out of the 12 or so bolts holding the exhaust manifold on....6 needed a good hit with the rachet and 2 were missing all together. A quick tighten and replace the missing nuts and job done.

So I took it for a fang down the street, and the noise (I am proud to say) has GOOOONE! No need to get the tappits adjusted .

Anyways...this is where my limited mechanical knowledge kicks in...

On first impression it seemed to drive a little better...obviously quiter...but seemed to be more responsive on the accelerator, and just smoother all round really.

Would this be right, or am I imagining things? Would that amount of back pressure loss affect the motor that much?

P.S Going out later to get some locktite or something like that so they dont come undone again.

[-Mick-]

you probably plugged an exhaust leak and have proper backpressure again.......... I don't think you're imagining the small difference

[HotFourOk]

Yeah, and the disruption of flow may have been affecting performance too.

Nice job mate

[Shadow]

probably still worhtwhile getting tappets adjusted if they havent been done for a while

buy a set of feeler guages and a gregories manual and you can do them yourself, HJ60 doesnt erequire shimming etc.

[G_loomis]

probably still worhtwhile getting tappets adjusted if they havent been done for a while

buy a set of feeler guages and a gregories manual and you can do them yourself, HJ60 doesnt erequire shimming etc.

now ya lost me...WTF is shimming.

and what exactly is involved with adjusting tappets.

[Shadow]

probably still worhtwhile getting tappets adjusted if they havent been done for a while

buy a set of feeler guages and a gregories manual and you can do them yourself, HJ60 doesnt erequire shimming etc.

now ya lost me...WTF is shimming.

and what exactly is involved with adjusting tappets.

The 2H has a nut with a bolt in the middle which takes a flat blade screwdriver. You undo the nut and you can then adjust the tappet clearences, you use the feeler guages to set the required clearence.

The 1HZ and several hilux engines require shims to adjust the tappets, not just undo-ing a nut and turning a screw, you undo a nut, put a shim in, check it, need more shim? etc. Ive never done one that required shimming so im not sure on the exact process.

You can download the 2H toyota engine manual here http://www.birfield.com/downloads-cat-1.html which details the esxact process with the clearence specs and even pictures! or you can buy the gregories which says the same thing.

[G_loomis]

thanks for that...another usefull (one day) piece of mechanical knowledge learnt

[dow50r]

does the motor have a turbo??? a snail looking thing on the exhaust???
Maybe the loose manifold was leaking potential boost.
Andrew

[G_loomis]

nah...no turbo...............














































YET

[Rainbow Warrior]

Yep my experience with exhaust leaks is they make engine run like shit if uneven as cylinder gas flow probably runs back up a pipe to go easy way out and runs into gas trying to come down pipe from other cylinder.

You also lose some torque down low with not enough back pressure, fired up a Holden red motor engine once without the manifold and it's freaky to be able to see the flames in the cylinders as the valves open & close, put the manifold only on so I could drive it down to exhaust place to have extractors fitted and it didn't drive to bad and was only loud at throttle