I did a dry compression test this arvo on the p38.
149
140
137
140
148
138
130
.... and 117
The 117 cylinder had a knock that is eminating from the inlet rocker - and I'm running 2.7mm of lifter pre-load. .. So im not sure.
The spark plug from that cylinder is also a tad browner than the others. On the right in the photo, and also had more oil on the very bottom of the thread when I pulled it out.
All the pressures in the cylinders dropped about 2psi when winding was stopped and dropped about 1psi per minute.
I've never done a compression test before, so I'm not quite sure what it all means. Can anyone shed some light?
Yeh it was. It started on the third attempt, straight up to 2000rpm for 17 minutes. I used all of the run in paste that was supplied. New genuine lifters with castrol magnatec.
The cam bloke I bought it off says is the fully synethic penrite that's caused it, even through its got high levels of zddp in it. ... even though it only did 8000km on the synthetic.
Not a good idea to run in an engine on Synthetic oil, My 2003 BA GT 5.4L DOHC V8 was run in according to Ford directions and the rings never seated in. Engine was changed at 15,000klms and run in on Mineral oil, then changed back to synthetic after 5,000Klm.
Engine was so much better than original once run in, SORRY just noticed you used a mineral oil, to break it in. Running synthetic after run in should not have caused the cam to wear, would be taking it further, was the cam an aftermarket product, Crane, etc., BTW did the bloke you bought the cam off warn you that synthetic oil would cause damage, Regards Frank.
It was from a notable cam supplier in Sydney - he's a good bloke and knows cams well. The profile was very good indeed, and delivered what he said it would. I just question his opinion about the synthetic oils with high zddp, and so have many that I've spoken too.
I put in a 215 cam from triumph rover spares last night, but he was saying a synthetic oil after run in would not do that damage.
I've considered bad quality lifters. As one was so badly damaged I had to drop it out the bottom, but most have minimal damage running on cam lobes that are stuffed.
Of course there's a myriad of other things. Was it hardened properly (sintered...case hardened?), was it a reprofiled can and the hardness has been ground off? Was the lift on the cam too high and was slapping the lifters rather than lifting them (it certainly seemed that the rising side of the lobes were coming into contact with the lifters in a flat 'slapping' fashion rather than caming them up)...
He did say to mail the cam back to him and he may be able to fix it - but I could only imagine that would take more of the hardened layer off.
The only way is to get it hardness tested...and I don't have time for that atm.
Done, dusted, and fixed as they say; just wanted people's opinions on the oil.
Wizard
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