T4 Tear Down / Rebuild in Jax FL

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Piledriver
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Re: T4 Tear Down / Rebuild in Jax FL

Post by Piledriver » Tue Nov 28, 2017 10:15 pm

Based on the photos it looks much better.
Do you have enough exposed threads for adjustment range as Ray noted?
(exhaust valve stems typically stretch over time//heat cycles)

I found that .080" shims under the rockers is usually a good starting point.
...about same thickness as a Tractor Supply 3/8" SAE grade 8 flat washer.
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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Wed Nov 29, 2017 10:47 am

Piledriver wrote:
Tue Nov 28, 2017 10:15 pm
Based on the photos it looks much better.
Do you have enough exposed threads for adjustment range as Ray noted?
(exhaust valve stems typically stretch over time//heat cycles)

I found that .080" shims under the rockers is usually a good starting point.
...about same thickness as a Tractor Supply 3/8" SAE grade 8 flat washer.
Thank you for the reminder. So the thought here is to space the rocker assembly out a bit, in addition to turning the adjusters so that they have more threads between the rocker arm and valve (which allows for more room for adjustments when the valves stretch)? OK.

Does that mean it's OK to cover the rocker arm oil hole?

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Re: T4 Tear Down / Rebuild in Jax FL

Post by Piledriver » Thu Nov 30, 2017 12:09 am

The spacers are actually to help fix the geometry.
A swivel foots pivot point is at the center of the ball (similar to a roller rocker geometry wise) rather than at the face of the valve. The spacers largely correct for this.

I don't see how blocking an oil passage would help anything, photos please.
I have cut a very narrow slot in the thread to direct the oil towards the valve spring etc.
It may even help...
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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Thu Nov 30, 2017 8:27 am

Found the SAE grade 8, 3/8 washers at Lowes, turned the adjusters in a bit more, extended the length of my push rod tool by about the same 2mm as the washers/spacers, re-measured for half lift, and tested this setup on both intake and exhaust valves...

Here are the results:

Exhaust
Zero lift:
Image

Half lift:
Image

Full lift:
Image

Intake
Zero lift:
Image

Half lift:
Image

Full lift:
Image


Oh, and I realized the ignorance of my rocker oil hole question after thinking about it. Stock adjusters always have their threads over the oil hole. I'll cut a small groove in the swivel foot adjuster threads like you and Clatter have mentioned.

My end-to-end push rod tool measurement came to 274 mm.

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Re: T4 Tear Down / Rebuild in Jax FL

Post by Piledriver » Thu Nov 30, 2017 8:42 am

Looks mo betta.
Hows the lift vs cam spec?
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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Thu Nov 30, 2017 10:03 am

Piledriver wrote:
Thu Nov 30, 2017 8:42 am
Looks mo betta.
Hows the lift vs cam spec?
Man am I glad you asked that question. I wasn't aware that that was something I should be checking!

This is a Web Cam 142 stock grind. Copied from their page, here are the specs:

Image

So intake @ .393 in, and exhaust @ .368 in.

I just measured and my results are:

Intake @ .392

Exhaust @ .362

Does this mean I need different push rod lengths, or is this close enough?

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Re: T4 Tear Down / Rebuild in Jax FL

Post by _thesatanicmechanic » Thu Nov 30, 2017 5:17 pm

That's lift measured at the valve or the pushrod? The specs and your readings...

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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Fri Dec 01, 2017 5:49 am

I measured from the valve

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Re: T4 Tear Down / Rebuild in Jax FL

Post by Piledriver » Fri Dec 01, 2017 9:54 am

Sounds OK, error is in the noise.
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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Fri Dec 01, 2017 11:03 am

OK cool.

When setting the geometry, should I make sure that when at zero lift I have the .006 lash? Or set the geometry, and then back the adjuster out to get to the .006? Seems like a stupid question, but I just want to be sure before I have these push rods cut.

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Re: T4 Tear Down / Rebuild in Jax FL

Post by Piledriver » Fri Dec 01, 2017 3:49 pm

When you get that close don't sweat it.
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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Sat Dec 02, 2017 5:40 pm

I couldn't leave well enough alone....

I mocked everything back up again, but this time made sure to leave .006 lash between the adjuster and valve stem when at zero lift. But now I can't seem to get back to .368 lift (for exhaust. I didn't re-measure intake yet). I now get .343. I tried changing the push rod tool, but got the same number again, despite a different length.

What am I doing wrong?

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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Sat Dec 02, 2017 8:54 pm

I think I'm over thinking this...

When the engine heats up, lash will be reduced, and the valve lift numbers will be at manufacturers spec.

New builder paranoia here :roll:

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Lo Cash John
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Re: T4 Tear Down / Rebuild in Jax FL

Post by Lo Cash John » Fri Dec 08, 2017 12:57 am

Man, from here at my laptop that's looking pretty close. If you need to shorten that adjustable pushrod let me know.

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Re: T4 Tear Down / Rebuild in Jax FL

Post by analogtherapy » Fri Dec 08, 2017 9:03 am

Lo Cash John wrote:
Fri Dec 08, 2017 12:57 am
Man, from here at my laptop that's looking pretty close. If you need to shorten that adjustable pushrod let me know.
Hey John, how've you been?!

Yea, after getting everything measured, and coming up with the push rod length of 274 mm, I did it all again and got 275 mm. With things having been checked multiple times, and getting a measurement that close I felt confident about it and shipped the push rods off to EMW to get cut.

Hopefully, once I get them back things should start picking up! I suspect my next big step (after putting the engine back in) will be tuning the carbs.

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