Mk4 w/BP347: oil pan clearance (below frame tubes!)

[Grubester]

I talked w/FF and also BPE and James at BP (the F5 connection) about the condition of zero clearance for the oil pan.
Mine shows the oil pan to be about 1/4" to 3/8" lower than the 4" frame tubes. This bodes ill for the first warning noises of "something scraping".
James said the 302 & 347 use the same pan and it is the case they hang low.
Fixes... if I were to run a skid plate or custom skid plate, it further impacts ground clearance.
Are people modifying ride height just for this condition?

[Jeff Kleiner]

A couple of thick hard washers between the block and engine mounts will raise it. Just ensure that you have sufficient thread engagement on the bolts and adjust the bolt length if necessary.

Jeff

[Grubester]

Hadn't thought of that! Easy fix, though it will raise the tailshaft/trans the same amount if I keep the centerline of the eng/trans level. I'm already ~1" above the center of the pumpkin's flange. If I add 1/4" or 3/8" at the engine mount-points, is that putting the "offset" of the two center lines too far out?

[rich grsc]

There is no need to keep the engine level

[Grubester]

rich grsc: thanks very much for your comment. I guess this is what I'm chasing... the correct way to address engine/transmission/IRS pumpkin alignment. I have no car experience or fabrication experience, that informs me on this topic. Earlier today, I talked with Dan Golub at FF and he said to make sure the car is level using the 4" tubes as reference and then establish the centerline of the eng/trans as level.

(my next comment starts to devolve into discussion about the driveshaft alignment:)
I don't know what drive shaft universal joints are designed to handle: there's the everyday working of them, and then some exceptional deflections (which they can handle). For the driveshaft apparently you don't want it perfectly aligned: I'm guessing it causes "fretting" in the needle bearings because they aren't receiving at least a little rotational movement against their races. But at what limit are they being "over-exercised" due to too much angle when they were set up?

[rich grsc]

With IRS, you will never approach the max limit of the u-joints, not even with a solid axle car. I grew up using equipment with PTO shafts for power transmission, the deflection angles they can run at are WHAY beyond anything you would ever see on these cars. I just shake my head at how this issue is SO over thought & debated. Just install it like Factory Five built it, and it'll be OK

[gbranham]

Totally agree with Rich. I know what the assembly manual says, but for folks who are building these cars that know nothing about cars, they fixate on strictly following the manual, with no real understanding of what they're doing. I get it...I've been there. But this is one area of the build you don't need to obsess about. Rich is correct...install your engine and driveshaft and move onto the next task.

[Waterman]

So I have to disagree in a car application, about never approach max angle, as I JUST went thru this. At 4 degrees driveshaft angle, which was visibly not level, I had vibration. I was attempting to have engine and diff parallel with a large tranny spacer but found better to minimize universal angles. I agree you do not need to overly fret about it but angles need to be reasonable and my recent post mentions the mfg's suggested limits. My Mk4 experience with thin seats cushions.

[Mike.Bray]

At 4 degrees driveshaft angle, which was visibly not level, I had vibration.

4 degrees won't cause a vibration, think lifted 4x4 trucks. I'm betting you had the u-joints too much in phase so there wasn't enough load on the driveshaft.

[Derald Rice]

Is the pan too low, or is it just the drain plug that is too low??

If it is just the drain plug, I removed the drain plug and re-tapped the pan for a 1/2 inch NPT tapered plug with an internal hex drive.

And without the hex head of the original drain plug, I gained 1/4 inch additional clearance.

Just be careful when you are tapping the pan for the plug, so that it seats when the top of the plug is
level with the oil pan...If you tap too deep the plug will not seat, and will not seal.