Roller build a-go-go

Post date: Jan 8, 2018 10:47:47 PM

As usual, I threw caution to the wind and decided to change to a roller cam. In the process I've managed to lean many things.

1) Ignition swaps are never easy

2) ATF-soaked header wrap can, and will, catch fire

3) Roller lifters raise the pushrod seat almost 1/2", which causes problems on a small block

4) Oil cooler thermostats are evil

5) Hand-drilling large holes on an engine block is ill-advised

6) Even after reminding myself to install the rear main seal, and keeping it with the caps, I can still forget to install it

I'll update the engine page with the new specs at some point. The cam is roughly 235/241, 0.58" lift. Idle vacuum is down to about 12". Qjet needs more massaging on the idle circuits but runs pretty good.

Crank:

Cut 10. The grinder called me to make sure I meant what I said - it's past the loose end of the book tolerance. But with 15w50 oil, hot idle is 35psi!!

Block:

Tried to implement Milan's oil mods. The machine shop was waaaay behind, and I was in a rush, so I only asked him to drill the vertical galley in the mill. He didn't like how little meat there would be with a 9/16" hole for the 1/2" time-sert, so he drilled it to 1/2". The hole was originally about 0.410". Time-sert went in just fine. I special ordered long drill bits off Amazon - the passenger galley was easy, but I burned the bit. Then the filter holes... Well, I didn't get them square. Thankfully I stopped myself before busting out the side of the block. So it's no worse than original, but not necessarily better. Also tapped the holes 1/2" NPT, with a new tap from Fastenal because my hardware store tap wasn't healthy enough. 2' breaker + 1/2" NPT tap in cast iron = good times. Now I also have an adapter block, with fittings, with absolutely no use for it.

Barr also did a very light (3 or 4 passes!) hone.

I noticed a small gouge in #8 after all the pistons were in. I just hit it with some 400 grit and cleaned real well.

Oil pump:

The Sealed Power sourced Melling pump was really dirty. So I grabbed a Schumann pump. It only had a few differences - no coating on the driven gear, anti-cav divots drilled on the bottom of the gears, a socket head bolt to load up the bypass spring, and bypass spring cotter pin replaced with a screw and nylock. I replaced the nylock with two nuts. The real value is supposed to be hand-selection of gears and honing of housings. Rather hard to verify that at home though. Was it worth it? I dunno, maybe.

Bearings:

All Calico coated. Basically doubled the cost of the bearings.

Timing:

Moved up to the billet -10 Cloyes set. Light tap put it in place nice and tight, ICL of 107.75degrees. I also might-as-well'd an ATI balancer and got a trigger bracket from Chadman. It's a very trick piece, but he made it for use with a 1/4" front plate and electric pump. So I had to lop off the top end of it, grind down one mounting pad on the pump, make a longer indicator, open a hole so I could use the stock upper bolt, and ground clearance for the PS bracket. In retrospect it would've been smarter to remove more from the PS bracket instead of the trigger bracket. There's potential for the trigger to wobble now, but it's still pretty stout. Also got the pickup, but have to special order the trigger shell from ATI.

Cam button:

Initially intended to use Andy's cam spacer, but turns out the assembly was too thick even with just the fuel pump eccentric. Had to sand ~0.015" off the bronze bushing. That leaves the nose pretty thin (<0.1").

Valvetrain:

Reused the HSG 5016 rockers, all seemed in just fine shape. New pushrod length 7.950". Went with Comp hi-tech 3/8" pushrods. Honed one end of the pushrod with a 3/32" bit and pressed in a 3/32" roll pin to act as a restrictor. Ones that collapsed got re-opened with a 0.050"-ish bit. Turns out a jewler phillips is the most useful press tool. Only ruined 4 pushrods. The restricted part that can hold the roll pin is quite short, then the pushrod opens up. So 4 ended up with roll pins rattling around, and three of those now have parts of drill bits stuck in them. Cromoly is serious stuff.

Heads:

Just did a cleanup. During test-fit I noticed that the pushrods got awfully close to the entrance holes, so I hogged them out. Of course, I didn't re-check - it was just close, and I hogged a bunch. You know where this is going. One of them isn't quite open enough, so #2 exhaust taps. Going to try moving down to 5/16" pushrods on that cylinder, see what happens. It'll probably self clearance eventually.

Intake:

Shaun welded up the void in the injection intake and it looks really good - like nothing ever happened. The shop cut each side 0.030" and it seems to fit quite well. Dry fit isn't perfect - pushing down one side causes 0.010" gap on the top on the other side - but it appears to be close enough for the SCE gaskets.

Ignition:

Tried initial run with the Fast dual sync @ 50deg offset. Spark scatter galore. Moved the pickup to the 0deg offset. No better. Pulled that distributed, put back my gutted Accel. Still messy. Realized #6 and #8 plugs got pulled off. Finally got it running. Spark scatter can lead to combustion in the headers, which leads to glowing red headers. Cool looking, but probably not good for the engine.

Oil coolers:

Broke the cast body of one when putting in the -10 fittings. NPT is a PITA. Got a replacement. On the first drive, the oil pressure would be >60 when cold, then once it warms up it would flutter and plummet to 25/30 psi and stay there, no matter what RPM. I still drove it about 10/15 miles.

For kicks I got some 1/2" copper elbows to bypass the thermo/cooler. Pressures were great! Ergo, something wrong with thermo and/or cooler.

In a fury, I got a super fancy Innovative Racing thermostat to replace the el-cheapo Derale. In the shower I got to thinking about it - in the old setup, the pressure bypass was still on the block. If the Lincoln oil cooler is too restrictive, then once the thermostat shifted, the bypass would just open and I'd run dirty oil with no notice. That will certainly lock up a lifter.

So new theory was the cooler is too restrictive (it was meant for ATF, not nearly-solid engine oil). So I grabbed a Derale 1000 series stacked plate cooler "just in case".

Get the fancy thermostat installed still using the Lincoln cooler, get it warmed up, and pressures stay excellent! Hot idle over 35, rises with RPM. Oil temp slowly rises to 180, then stays there. Cooler lines are obviously hot and warm. The Derale cooler acted completely different - temp tended to get up to 140 and stay there.

So maybe the cooler is fine? I don't know.

Oil lines:

Upgraded the lines to the block to -10. I boogered one fitting trying to assemble it, but Shaun got it cleaned up. One of the straight fittings drips when hot. Going to replace it with a 45deg on the block end.

Transmission:

Sent the governor to Extreme to recalibrate. They put on weights about mid-way between the weights that were on there and stock heavy weights. I have some comparison pictures. Not enough drive time yet, but seems better. I picked up a stock governor with heavy weights as a backup in case I modify too far.

Bonus:

Scraped the insulation off the roof (very messy), and got most of the body freshly sanded.

So hopefully at this point I'll swap out a couple of pushrods, fix up one oil line, and get back to driving. I hope to put a few hundred easy miles on it. Also need to finish sanding the body, and hopefully it goes into the body shop later this month.