mark kibort

I think its the original MAF, but i could be wrong.

its never been "oiled" . I use the KN but only very lightly oil the outside, not the side facing the MAF.

I do have a air fuel meter, that seems to coorelate well with the dyno runs that show good air fule ratios from top to bottom.

mk

mark kibort

I think its the original MAF, but i could be wrong.

its never been "oiled" . I use the KN but only very lightly oil the outside, not the side facing the MAF.

I do have a air fuel meter, that seems to coorelate well with the dyno runs that show good air fule ratios from top to bottom.

mk

alex70

That's funny, didn't catch the 9th cylinder

rich

mark kibort

That was the holbert power secret. I wondered why i was always 1 plug short when my tune up order arrived.

mk

AO

I thought that's what the "9" stands for in 928.

SwayBar

That's what most engine builders recommend. One reason is that using the four-electrode sparkplugs provides 3 additional hot-spots to potentially form in the combustion chamber, thus a greater chance for detonation. Plus, using platinum plugs with the stock gap shows a horespower reduction.

http://www.se-r.net/engine/platinum_copper_ngk.html

mark kibort

Ill i know is ive seen one of those "4" electrodes end up in an engine. no thank you for that alone! I didnt know about the platinum issue. i used them in my original 5 liter euro because they were spec'ed for the 84S originally. (and they cost more so i thought they should be better!

Mark

mark kibort

I just checked my belt tension and still see that my pulleys are off by about 1/2 of a tooth. I know this has nothing to do with cam timing, as long as they are adjusted in this position. however, im wondering how they can be off. seems like that would be dictated by a belt geometry , and engine geometry thing.

the driver side is almost dead on at TDC, but the passenger side doesnt quite reach the timing mark by about 1/2 of a tooth. Its almost far enough off where i could move the pulley and the belt one tooth and then have it be forward of the indicator by near 1 tooth. maybe this is where it should be. (i just cant remember if i have changed the belt since i did the cams originally. I suppose it doesnt matter, if i havent touched the belt since i adjusted the cam timing)

thoughts???? could this cause 5-7psi difference from bank to back on compression??

actually, now that i look at the pics of the two cam pulley line ups below, its probably as good as its going to get. the passengerside is really only 1/3 of a tooth behind the mark, while the bottom picture shows the driver side only a fraction of a tooth behind the indicator mark.

mk

SwayBar

After timing my GT cams, the sprockets ended up in the same position as yours, so I think we're both good-to-go.

Bill Ball

With a new belt, it's almost always right on the money. If the belt stretches, it HAS to go out of time. If you want, I can bring over PorKen's tool and we can see what it tells us about the cam timing. I'm free almost any day.

PorKen

Thanks, Bill! I was just writing that I would loan Mark mine to check it out when you posted.

To be accurate, cam timing, either using the dial indicator, or a 32V'r, should be done with a seasoned belt. As a new belt stretches, the timing is retarded.

According to the compression results, it seems either the 1-4 side is retarded, or the 5-8 side is advanced by a few degrees in relation to the other side.
...

BTW, using colder plugs gives you a teensy bit more compression! Try the WR5DC+, they're cheap! There's no downside. Just verify that the tips stay clean after regular driving.



WR7DC versus WR5DC - the insulator heights look strikingly like this pic.