[HWYSTR455]

FormulaJones - Thank you for a detailed response, much appreciated! Would be interested in more details on the mods required for the Chevelle pan, probably more than this thread should have. (Maybe PM me)

Cold air, that too is a very good point, and guess with EFI, it would have less effect/improvement, but cold air is still an improvement. IAT readings fatten it up with colder air, hence, more power. (theoretically)

I agree, functional on the 68 in discussion would be a cool/wow factor, and at a lower power build makes much more sense. Well, if you consider 525-600 a 'lower power' that is!

On the #5 clearance, wasn't the factory spec bigger for #5 too? I thought for some reason it was like .0003-.0005 more than the rest, but I honestly can't recall specifically. (Wish I wasn't living out of boxes right now)


.

[Formulajones]

Originally Posted by HWYSTR455

FormulaJones - Thank you for a detailed response, much appreciated! Would be interested in more details on the mods required for the Chevelle pan, probably more than this thread should have. (Maybe PM me)

Cold air, that too is a very good point, and guess with EFI, it would have less effect/improvement, but cold air is still an improvement. IAT readings fatten it up with colder air, hence, more power. (theoretically)

I agree, functional on the 68 in discussion would be a cool/wow factor, and at a lower power build makes much more sense. Well, if you consider 525-600 a 'lower power' that is!

On the #5 clearance, wasn't the factory spec bigger for #5 too? I thought for some reason it was like .0003-.0005 more than the rest, but I honestly can't recall specifically. (Wish I wasn't living out of boxes right now)


.

You are correct, at least the one old book I grabbed does have the #5 main with slightly larger "range" for oil clearance. I don't know if all books or more recent books are like that.

I'll send you a pm.

[Verdoro 68]

Originally Posted by Formulajones

I'm still of the mindset that the OP's setup would look killer with the 68 system intact and functional. He likes period correct making the car appear as if he would have built it in 69-70 using over the counter OEM performance parts, as he mentioned in an earlier post, and to me the 68 RA pan setup is at the top of that list.

Twist my arm The main thing holding me up from adding the ram air gear is that I don't want to cut the hood. That said, I did punch a 4" hole in it for a hood tach and my scoops are already open so...

Originally Posted by HWYSTR455

On the #5 clearance, wasn't the factory spec bigger for #5 too? I thought for some reason it was like .0003-.0005 more than the rest, but I honestly can't recall specifically. (Wish I wasn't living out of boxes right now).

Originally Posted by Formulajones

You are correct, at least the one old book I grabbed does have the #5 main with slightly larger "range" for oil clearance. I don't know if all books or more recent books are like that.

Interesting - which book are you looking at? The '68 service manual only shows .0002-.0020 for all main bearings. (.0002!!??)I looked in an old Chilton's in addition to Rocky Rotella's books and they all listed a uniform range for all mains. I tried calling Butler today for advice, but they're closed for the holiday.



While I figure out the bearing clearance situation, I picked up on a few other things. First, I primed and painted the block, new valley pan, new Canton pan and repro front cover. A while back I found a snafu on Amazon's site and got a 6 pack of Pontiac Duplicolor 1616 for $15. Came in handy today.



Next, I checked the crank endplay. I rigged up a dial indicator from my cam degree kit, I hope that's kosher. I couldn't get it on the crank snout, so I set it up against the first counterweight. Looks like I'm at .007 which is in the acceptable range. I also test fit the factory windage tray with spacers to make sure it's going to clear the crank (it will, no problem).



Finally, I got familiar with the Total Seal ring pack and set up the ring filer. The instructions say to go for .012-.022 for my bore size. I looked through some old threads and it seems like the consensus is .016-.018 on the first ring and .020-.022 on the second, although Cliff mentioned he does .018 on both. I have the first one at .017 right now. Taking this first one slow and being very careful to ensure I'm filing square and not taking too much off.

[PunchT37]

I have a 1971 GM service manual and a 1976 Motor manual. Both show #5 clearance the same as the rest.

[HWYSTR455]

Just to say, on the ring gaps, I always cut mine to include a street/strip N2O shot, no harm in doing so, even at large gaps that 'standard', you won't have any additional or measurable blow by. Your call on that. IMO, better safe than sorry. Too little can cause way more damage.

I too believe the 2nd ring gap should be a touch larger, there again, your call.

.

[HWYSTR455]

I use a stone to treat/deburr all edges on the ring ends too.

It's ok if the rings vary slightly, .001-.003 more on any rings is not going to cause problems. Sure, try to get them all the same, but it really isn't going to make any big diff.


.

[Verdoro 68]

Originally Posted by HWYSTR455

Just to say, on the ring gaps, I always cut mine to include a street/strip N2O shot, no harm in doing so, even at large gaps that 'standard', you won't have any additional or measurable blow by. Your call on that. IMO, better safe than sorry. Too little can cause way more damage.

I too believe the 2nd ring gap should be a touch larger, there again, your call.

.

According to the instructions, Total Seal says to go .0045 per inch of bore for both rings. 4.17 x .0045 = .018765, so I ended up filing on the looser side of .018 for both first and second rings. I'm open to suggestions if that sounds like it might cause problems.

I did find it suprising that you install the inside taper differently for the top and bottom rings. The instructions aid it should be installed facing up on the top ring and facing down on the bottom ring (dot facing up).

Originally Posted by HWYSTR455

I use a stone to treat/deburr all edges on the ring ends too.

It's ok if the rings vary slightly, .001-.003 more on any rings is not going to cause problems. Sure, try to get them all the same, but it really isn't going to make any big diff.
.

I took my time filing the rings so they're all really close. I'd say .001 variance at most. I deburred the edges as well.

I cleaned all the pistons while I was at it and found some shavings from the machining process. Good reminder to clean and check all your parts.

I also installed the oil galley plug with the .040 hole for distributor gear oiling.