bzoli

Question #2:
I'm searching for engine rebuild kits.
So far I have found the following ones:
rpmmachine
flatlanderracing
cleggengine
perfectengine
northernautoparts

Anyone could make recommendation or experience with engine rebuild kits from list above or anything else, please let me know.
Thanks

River1

Living in San Diego you should not have a problem finding an "Industrial Bolt and Fastener Supply" or something close to that name. If they don't have it, they can get it. You might be amazed at the enormous amount of combinations of materials and grades of bolts there are. If you want to spend the money you can even get a grade where every nut and bolt has been examined by X-Ray and NDT or non-destructive testing has been done. Might cost as much as $50 to $100 a piece, but you know they are not going to fail.

Just did a quick Google search in San Diego for you and 52 come up. With the Navy there I'm not surprised.

bzoli

It seems a local dealer was able find one set of main bearing cap bolts in LA area, which has one set in stock. Seems I got lucky.

Next is disassemble the head and decide on rebuild kit or piece it together.

I will replace the crankshaft with a reman from ford as the crankshaft journals has slight scoring. The crankshaft should come with size matched bearings.

97XLT4.2

Glad you were able to find those bolts! If the crank only had slight scoring, would it not be cheaper to have it machined when you are getting the block done? I was able to get away with just polishing mine but it had been machined before so it had very little scoring and only on the main journals.

bzoli

Agree. I will check this option before ordering a crank from Ford.

bzoli

I removed the valves. Again I don't know how it should look like, but I expected the exhaust ports to be relatively clean as hot gases would keep it clean, the gas velocities are much higher, while I expected some oil-gunk build up on the intake from EGR and crank case gases. It turned out the be the opposite.
The exhaust valve didn't seem to seal perfectly (poured oil on top and pressured with air - it started to bubble). The exhaust valve and valve seat contact surface is not clean. The intake valve shows nice contact with the valve seat.
I should have done a leak down test prior disassembly.

Some picture from the valve seats
Exhaust valve seats:




Valves

Manuellabour247

For 140k miles on a 4.2, that doesn't look too bad to me. It's not good, but it's not terrible compared to some others I've seen. The hot gasses are binding to your valve and seat on the exhaust stroke. There's not real way to prevent this from happening over time. The best thing to do is buy a good gas, some say top tier fuels I say just good gas. Different aged tanks from gas stations can have stuff in them from the liner, dirt from the fill port, etc. You might run some seafoam in your engine if so inclined, but that might start a war amongst the other truck owners as far as what to use. Lol.

bzoli

Thanks for your input - good to know that they look about normal after 140kish run time.
Tomorrow I will measure the valve seat width it should be 1.4-1.6mm per manual, than check the vale stem diameter. I presume the valves need to be cleaned and than can be reused.

bzoli

Hey guys,
I have another question. I started the assembly, the cylinders were bored over 0.5mm (0.02 inch) the machining came out pretty good. Today I have checked the piston ring end gaps in the bore. The manual calls for 0.17-0.33mm end gap for the top compression ring, 0.3-0.55mm for the second compression ring.

The federal mogul ring measured close to 0.5mm.

The general rule of thumb (manley, CP etc) is 0.004-0.0045 per inch of bore (3.83 * 0.004 = 0.01532 inch, 0.389 mm). So it is close to the upper limit but the 0.17 mm seems small.

Regardless I would like to stick with Ford recommended end gap spec, maybe tend towards the upper limit. But I measured close to 0.5mm

I see two options, leave it as it is, accept the 0.5mm, or exchange the 0.5mm over ring to a 0.75mm over rings.

Any recommendation?