This is my tow rig. There are many like it, but this one is mine.
Period correct, even!
I was prepared for another season of loading the race tires in the back seat, filling the trunk with tools and spares, and driving myself to all my events in the car. Alas, my emergency get-home-if-I-break spot in a friend’s trailer was taken for the year by an another car, so I had to start looking for a tow rig. I’m travelling too far and pushing the car too hard. I’ve already had to be towed home from multiple-hours away three times by friends. Time to stop mooching .
Thankfully, this setup pretty much landed in my lap. The truck is a 1990 F-250 with the four speed E04D transmission and the venerable 300 cubic inch inline 6. The truck has a paltry 121,000 miles, with 21,000 being added up only since 2000. There’s some rust on the fender arches and the bottoms of the doors, but the bed is solid and the interior is nearly perfect. I snagged it from the grandmother of a friend. They’d been using it to tow a boat for the past two decades, but were boating folk no longer.
The truck’s mechanical bits were sound, but she needed some love. The braking system worked, but hadn’t ever been serviced, so aside from the pistons that moved when stepped on the pedal, the entire system was rusted into a solid mass from the inside. I had all of that replaced. I also changed all the fluids.
The trailer is a Gatormade 16 foot. This also fell in my lap when a friend jumped on a deal for an enclosed trailer for his Exocet.
This is a tub of oil. Note, there is no metal floating in it. This is fantastic news. I had prepared myself for the disappointment of seeing a sheen on the surface of this. The lack of visible metal in this oil is invigorating. Confidence building. Exuberation ensued.
This is drain of the 500 mile oil change. The purple dye is still intact. It’s been refilled with 5 more quarts of 5w30 Royal Purple and a new Mobil1 filter. My first event of the year is the Charlotte Match Tour, followed two weeks later by the Optima USC Event at NOLA. The car is ready.
There wasn’t supposed to be a part four to this series.
But there is. Sadly.
After getting about fifty miles on the car and changing the oil three times, even stepping up to 15w40 truck oil, I still had an oil pan full of metal, a tick I didn’t like, and really low oil pressure at hot idle. Like 4-6psi low.
So I pulled the engine out and took it back apart. The source of the problem was located inside the oil pump.
I’d fallen victim to complacency. I didn’t check the pump cover before installing it. The guys that built it for me had already packed the pump gears with Vasoline and I didn’t want to take it apart and repack it after checking it. That was a mistake.
The oil pump on a Buick V6 is driven off the camshaft by the cam sensor. In a carbed application, this same hole would house the distributor. Like many other engines, the cam sensor/dristributor has a tab in it that fits into a slot on the pump drive shaft. If this alignment is not spot-on, the cam sensor and camshaft side-load the pump shaft, which rocks the pump gears into the sides of the pump cavity and into the thrust surface. If the clearances are too tight on one side of the gears, that means they’re going to be too loose on the other side. Oil bypasses the gears through this extra clearance, and voila! Low oil pressure.
The pump gears also ground against themselves and the pump cavity, releasing metal into the engine.
Most of the bearing shells were scored, as were the cam bearings. The crankshaft was unharmed.
So, the entire thing went back to the machine shop to be cleaned and have new cam bearings installed.
I also went back to my friend’s shop and we pulled his entire stock of brand-new timing covers. We checked them all with a set of new pump gears and my cam sensor. All of them had bore alignment problems. Every. Single. One.
So, don’t trust the new pump covers. ATP, Pioneer, Silver Seal, TA? All of them use essentially the same casting from China. Some of them spot-check their incoming stock to see if they’re junk or not. Some don’t. And even the ones that do can miss a batch. If you buy one, put it together on the bench and make sure the assembly turns properly. My friend had a used original GM cover that checked out. I’ve already ported it. Once I get it tanked (it’s pretty grimy) and painted, I’ll be able to finish putting the engine back together.
I also resurfaced the filter adapter.
And the short block is back together already. Once the timing cover gets back from cleaning, I can re-set the cam endplay, assemble the oil pump and pack it with fresh Vasoline, and finish assembling the engine. Again.
In the last installment, I brought everybody up until the engine was in the car.
Now for the home stretch.
New battery cables finally arrived and were quickly installed. I filled the crankcase with five quarts of Comp 5w30 engine break in oil and primed the engine with a drill.
With the electrical system finally hooked up, it was time to turn the key and see if we had brain activity, which I did.
After that, I pulled the spark plugs back out. Why? With no compression, the new high-torque mini starter was able to spin the engine at almost 600rpm, further ensuring the oiling system was primed.
Then I put five gallons of Kroger’s best pump 93 in the tank using my trusty Purolator pump and the old battery from my girlfriend’s Mercedes.
While the pump was doing it’s job (which was making me not have to hold a five gallon can and pour it), I put the spark plugs back in and ran the plug wires. And then I started it, right?
Nope. I first hit the terminal near the driver side valve cover that turns on the fuel pump. Lo and behold, a fuel leak quickly manifested. I had sealed the fittings for my fuel pressure sensor with teflon-based paste. The gasoline ate right through the stuff. I had to disassemble the section and put it back together using the teflon based tape. Fifteen minutes max.
Then? Well, watch for yourself:
No smoke (except the header wrap baking in), no issues. We put the hood back on it the next day.
In our next installment, fixing the brakes for what I hope is the last time:
When we left off back in December, I was waiting on a small base-circle camshaft to clear my stroker rotating assembly. It came. It cleared. Hooray.
With that done, it was time to assemble in earnest. The first step was to bolt the heads on and measure for pushrod length. I won’t go into detail on that process, because there are a ton of tutorials already out there. Suffice to say, I ended up needing 8″ pushrods. I ordered a set from Smith Brothers, and promptly installed the valvetrain.
Also installed was the front cover. This is a blueprinted cover from Boost Crew Motorsports. The oil pump has been ported and clearanced, and it was spot faced for my roller cam button.
The balancer went on next, followed by other items like the oil pickup, the new lightweight (10 pound savings!) start motor, and the oil pan.
Getting the balancer installed required making a plate to go between the bearing on the balancer installation tool and the balancer. The bearing was just a tad too small and wanted to ram itself inside the balancer. No bueno.
The flexplate went on next, and then the engine went in the car.
One would think, “Hey! It’s in the car! Easy from here, right?”
First off, the fancy SFI approved super-duper flexplate didn’t line up properly with the torque converter. When I zipped the bolts in, they kicked sideways and cross-threaded the converter holes. Bad. So the engine had to come back out, I had to helicoil the converter, and enlarge the bolt holes on the flexplate. This wasn’t easy. Both the converter mounting flange and the flexplate are made of super high strength steel, so cutting into it was very difficult.
But I got it.
Then, I was staring at a pile of dirty accessory brackets and accessories. Not acceptable. So a can of Dupli-Color aluminum engine enamel and several coats of clear and a lot of patience netted me some pretty blingy parts. The accessory bracket cleaned up really well, and I even disassembled and painted the alternator.
With the accessories complete, it was time to bolt the intake manifold down.
And it didn’t fit. Since the block has been decked twice and heads milled twice, the bolt holes didn’t line up anymore. Back to the machine shop it went to have 0.010″ taken off each flange. While they had it, I had the manifold completely ported and the EGR tower cut down and epoxied shut.
While waiting on that, I undertook the extremely frustrating act of wrapping my headers. It was difficult. This stuff is so maddening to deal with. You get a wrap started, and just when you’re ready to tied it off, you slip and it loosens and you have to start over again. Nevertheless, I persisted, and they didn’t come out half bad.
After that two week delay, the rest went together pretty quickly. I made a small bracket to mount my new boost control solenoid.
I dressed up the wiring and got almost everything buttoned up yesterday. I’m waiting on a few push lock fittings and new battery cables to show up in the mail, and we’ll be set for a first start in the next week or so. I also have a new coolant overflow bottle on the way to replace the one I melted last year.
If you follow my blog, you’ll remember my posts back in August (here and here) detailing the failure of my engine at the Optima Search for the Ultimate Street Car event in New Jersey. I started my rebuild story in another post back in October. Many may be wondering what happened? It’s been over a month!
Well, as it turns out, parts for this car are getting hard to get. Added to the availability issues are the nature of the build. High strength, non-standard reciprocating assembly, and custom fitting billet steel main caps resulted in an extended stay at the machine shop.
But the time to move forward has finally arrived! The block and reciprocating assembly came home just after Thanksgiving.
I had intended to make this a single post for the whole build, but it turns out that’s probably not going to work. I’m breaking it up.
In case you were wondering what kind of machine shop work goes into a build like this, here you go:
Disassemble/vacuum test heads
Resurface heads .010
Size piston wrist pins
Clean connecting rods
install 2 pieces mallory metal
Degrease and inspect block
replace freeze plugs
replace oil galley plugs
resurface block .005
Check block height
Clearance for stroker kit
File Fit rings
Main cap fitting
Block line bore
Cam bearing install
All of this work took eight weeks to complete at two different machine shops and cost almost two grand. For just labor. Let me say here that this will be my last Buick V6 engine build. If it pops again, I put an over the counter reman long block in it and sell the car.
And while we’re doing bullet point lists, here’s the parts list, at least the fun parts:
Carrillo Forged pistons (custom wrist pin height, standard dish)
PAC valve springs
Erson roller lifters
Comp 264HR grind roller camshaft
Double roller timing chain
Cometic MLS head gaskets
All bearings Calico coated
With everything in house, I began putting stuff together. An hour with the valve spring compressor and the heads were assembled. Yes, an hour. I had to take them back apart once I realized I’d misinterpreted my machinist’s cylinder numbering and had put the valves in the wrong holes. Sue me.
Next came attaching the pistons to the connecting rods, which resulted in a pretty fantastic engine-porn shot.
The next part was assembling the short block. A 3.830 inch diameter ring compressor made this much easier than it was the last time I put this engine together. What had been a frustrating few hours with the ratchet type compressor ended up being about half an hour this time around.
I bolted the main caps on and checked the diameters. The clearances are all between .0015 and .0020 inches. Right at the tight end of the acceptable range, which is what I wanted. My intention is to run it tight and use really good oil instead of running it loose and filling it with 50w sludge.
Once the pistons were loaded, I spun the assembly around to make sure everything cleared, especially the #1 rod. It interferes with the main oil feed galley coming from the pickup to the front cover. My machinist clearanced the block and took a bit off the bolt head and it clears. Barely.
This the only clearancing the block needed. Other rods may require more. I picked the Molnars specifically because they clear really well.
I checked the endplay. .005″. Exactly where I wanted it. Tight.
What didn’t clear was the camshaft. There was interference between the rods and the cam lobes. I was able to get it to clear by advancing or retarding the cam six degrees, but I didn’t want to run the car with the cam that far out. So, the cam went back, and I ordered a custom small base circle version of the same profile.
And with that, here stops this installment. Stay tuned! Once the cam shows up, we’ll be installing it, then the lifters and heads, then measuring for custom pushrods!
I’m also hitting up PRI this week, so I’ll likely do an entry on that.
Most that have dealt with C-clip rear ends from GM and Ford know all about the good things. C-clips are easy to work on. It only takes a few minutes to get an axle out of the car. The bearings on the axle ends can be serviced with a slide hammer and rubber mallet, no need for a press or a trip to the machine shop.
What they don’t do well is cooperate with disc brakes, and all of the lateral load imparted on the axles hits the carrier bearings in the differential center section.
The axles float a tad, which is fine, except when the wheel hub is attached to the axle. Lateral movement allowed by the slop inherent in C-clip retained axles will cause pad knockback, even with a floating caliper. I’ve had trouble with it since I put the disc brakes on the back end of the car.
And lastly, since the axle is retained by the clip inside the center section, if you happen to break an axle, there is nothing holding the outboard section (and your wheel) in the car anymore.
Enter the C-clip eliminator kit. NHRA requires them in many instances as a safety item. They consist of a bearing block and bearing set that are pressed onto the axle, and then the assembly is bolted to the axle flange. Voila. No more C-clip, and the axle is retained at the outboard end, so if it breaks inside the housing the wheel stays on the car.
It also has the potential to reduce brake pad knockback, since all that slop from the c-clip design is eliminated. That’s the part that was attractive to me.
I looked at several C-clip eliminator kits. I first checked Moser, and they had one. But the instructions for the kit specifically stated they were not for street use. The end bearings were of a needle type, and had no ability to manage lateral loads well. These were drag-race only.
Strange had the answer. They offered a kit with both roller bearings for drag racing, and a street/track kit that used a tapered bearing.
The kit includes all the required parts and a single page (back and front) instruction sheet.
I’m not going to go through the install step by step, since that’s what the instructions are for. But I will offer a few tidbits here that weren’t in online writeups and youtube videos.
First of all, you have to drill on the axle housing. I found that the easiest way to get the holes right is to enlarge the lower holes in the flange, then bolt the inner guide plate to the lower holes, which enables you to use the upper holes in the guide as a jig to locate your drill.
A Harbor Freight 12-ton shop press is plenty for pressing the bearing assemblies on. At $99 with a coupon, the press pays for itself in a single use.
And finally, the “button” on the inner end of the axles, where the c-clip normally would slip on, must be removed. I was able to cut it off easily with the axle in a vise and a quality metal cutting blade in my reciprocating saw. The same saw also made quick work of the bearing housing on the end of the differential housing. That cut doesn’t need to be pretty.
If you’ve been careful with your drilling, it will bolt right on.
Now, here’s where my experience may help you:
I have a disc brake conversion. These kits are for cars with drum brakes. The caliper mount plate is much thicker (0.250″) than the standard sheet metal drum backing plate.
No worries! It can work! Before you perform the final assembly, slather some grease on the splines of your axle, and mock the thing up with the caliper plate in the sandwich where the instructions tell you to put the drum backing plate.
Then pull the axle back out. The grease should have been pushed down the splines and tell you just how much engagement you have with the center section. If you have at least 1″ of engagement, you’re good.
If you don’t have 1″, then you’ll need to call up your favorite axle vendor and order longer axles, since by the time you get to this point in the install, you’ve already cut up your housing and there’s really no going back.
Mine worked out just fine.
Also, with the disc brake plate in place, you’ll want to make sure the bolts that bolt the bearing plates to the the housing end are long enough to properly engage.
I’ll report back in the spring with whether these actually work out as expected. If they don’t, I’ll probably have a very broken and/or wrecked car. The big unknown is the strength of the flange on the axle housing. The GM 10 bolt assemblies in the G-bodies have a very flimsy (as compared to a Ford 9″ or a Chevy 12 bolt) flange.
However, I have a 0.250″ disk caliper plate sandwiched in the assembly, which should give it some additional strength.
So, this entry marks the beginning of my documentation of my engine rebuild. Any big project needs some goals. Without goals, you have no idea if you’ve been successful, or even if you’re complete.
With that in mind, let’s back up and talk about my goals for next year:
Multiple Optima USCA events, possibly as many as four
Multiple National-level SCCA events
MidWest Muscle Car Challenge
Enough local events to be competitive for a regional trophy
This is an ambitious list, but it tells me what I need to get out of this engine build:
Reliability – this new engine needs to be bulletproof.
More power – If I’m going to play in the Optima playground, I need more juice. The transmission can take it.
Less weight – The car is too heavy. Shaving a couple of hundred pounds will make everything better. Better handling, more tire life, less load on drivetrain and suspension parts, and on and on.
Better brakes – The brakes are inadequate. Even with ducting added, I cracked a brand new rotor at NJMP. One event per set of rotors simply isn’t sustainable
So those are the goals for the winter build. In this entry, I’m going to talk about the first two: reliability and power.
There’s an adage: fast, cheap, or reliable: pick two.
I have decided to pick fast and reliable. My last build was fast and cheap, and it is now going to cost me dearly. But if I do this right, I won’t have to touch this engine for three seasons, and at that point I should be just looking at a bearing and gasket refresh.
So what am I planning to address the reliability issues? Well, if you read my earlier posts diagnosing the failure, I need to address boost control, head sealing, crankshaft flex, and very likely heat.
The crankshaft flex leads to an obvious solution: a better crankshaft. This build is getting a 4340 forged steel crank.
4340 forged steel has double the tensile strenght of cast iron, and 50% more than cast steel. This crankshaft won’t bend like my stock crankshaft did. This will leave me with even bearing wear, less vibration, and an ability to handle much more power without twisting.
Connecting the crank to the pistons are the connecting rods. Since I trashed one of my OE rods, I needed a new set anyway. I again spring for forges pieces. Molnar H-beam connecting rods.
Being forged, these rods are at least twice as strong as the original cast rods. These rods feature ARP’s highest quality rod bolt set, and the small end is bushed in brass. Brass is an interesting alloy. It’s porous. It will actually absorb oil, then release it in situations where the oil supply is reduced, effectively lubricating itself. Plus the metal is soft, it will yield where other metals would scuff or even tear. This reduces friction at the small end of the rod. Less friction is less heat is less load on the oil and cooler piston which is less likely to detonate, and the wristpins are much less likely to break under extreme use.
Complementing the crankshaft and rods will be a JH SFI-approved neutral balance flexplate to replace my bent stocker, as well as a BJH SFI-approved neutral balance harmonic balancer. The SFI approval ensures the parts are a) actually balanced, and b) won’t explode at extreme RPM ranges. They’re tested to 12,000 RPM, double what this engine should actually see. That’s a large safety margin. On top of all of that, these new pieces are lighter than the OE parts by a couple of pounds. A pound off the crank is worth something like 3-4 horsepower to the ground.
Speaking of power, astute readers will have noticed the stroke marked on the crankshaft. 3.625. This is a increase in stroke of 0.224″ over the stock 3.4″ stroke. The rods are also longer to compensate for the stroke, and I’m currently waiting on a custom set of pistons to fit everything together.
This extra stroke is where I’m getting my extra power. It should be worth an easy 150-200 additional ft-lbs of torque and 50-70 horsepower. This additional torque and the airflow that comes with it will help the car’s ability to accelerate out of low speed turns on autocross courses, and the turbocharger will spool faster.
I will also be replacing several of the main caps in the block with billet steel units, to hold this new crankshaft firmly in place.
All together, these bottom end improvements will go a long way towards increasing the strength of the engine.
Stay tuned for future installments, where I’ll talk about the valvetrain, oiling, heads, how to keep it from detonating again, assembly, and tuning.
So, after my disappointing engine failure at the Optima NJMP event, I was left with the big question:
Well, after pulling the engine and tearing it down and reviewing the data logs from the event, even having an oil sample analyzed, the answer is clear:
Dealing with things like this requires patience. I want to understand what broke and why it broke. Without fully understanding those things, I’ll just break it again.
Step one is getting the engine out of the car. Not a big deal. This is my second time doing it. Had it out in just a few hours. Before I started pulling it, I drained the oil, taking a sample to have analyzed. No water came out, which was encouraging. But the oil did settle in the pan with a nice metallic sheen on the surface. That wasn’t encouraging.
After getting the engine on the stand, I got the intake manifold off and saw the first hard evidence of what I was dealing with. The passenger side head gasket had clearly failed at the top of number six.
It managed to push the gasket out far enough that it contacted the pushrod, likely contributing to the noise. Once I got the head off, the effects were more obvious.
You can see pretty clearly the damage to the gasket. On the bright side, the water that got into the cylinder steam cleaned the top of the piston for me. The gasket also mostly re-sealed, which is why I was able to drive the car off the track and onward to the paddock and eventually onto the trailer. Yay?
The driver side showed signs of damage, too. But not nearly fantastic enough for pictures.
At this point, I was feeling encouraged. Maybe I got away with just a head gasket? Time to flip it over and pull the oil pan!
That, my friends, is bearing material. Lots of it.
The number one cam bearing was damaged, as well.
I pulled the number three main, and it was trashed.
At this point, I just took it to the machine shop so they could clean it. They found the top shell of the number one rod bearing was missing. The rod journal had been ground down 0.018 inch from the original size, and the cap and journal were discolored from the heat. The crank was trash, and so was at least one rod. The wear on all of the bearings was offset, too. The crank bent. I bent the crank. The crankshaft bent. Holy crap.
So, that’s the physical damage. But what caused it?
Well, figuring out why the head gaskets failed was easy once I saw this chart:
The green line is the knock count. As boost climbed past 20psi up to 24psi, it starting pinging. A lot. I couldn’t hear it when it was happening. When it hit 24psi, the heads lifted off the block and the rest is history.
But the bearings?
Yeah, bearing wear. And checking out the slightly elevated number on the 8/5/2016 sample, it appears they’ve been wearing since I put the engine together. I think I screwed up something in the front cover and oiling system when I built the engine last time. They wore, and then the detonation event just finished them all off.
So, the total damage? Trashed crank. Trashed rod. Block is fine but will need some finish machining. I’m going to need a rotating assembly, new cam, and a properly constructed front timing cover and oil pump.
So what’s next? A lot. As is usually the case, it costs almost the same to put upgraded stuff into the thing as it would cost to just rebuild it as it was. I’m forging it all. All the things. Forged. FORGED!!!!!