I masked around the damaged piston and then used a scotchbrite disk on my die grinder to clean up the high spots. There are now no sharp points that could get too hot and cause preignition.
Afterward, I cleaned all of the RTV off of the intake manifold. That stuff sticks surprisingly well. I cleaned most of it off with a razor blade and then used a brass brush to clean off the remaining bits. I’ll use some solvent to get this spotless before reassembling the engine.
My dad took the heads down to the guy who did our dyno runs so he could take a look at them and the pictures of our piston damage. He didn’t seem too concerned and recommended we resurface the heads and clean the high spots off the the piston.
He put the heads on the resurfacer and used a dial indicator to check for flatness.
They were off about 0.0015″ across the whole surface, so he reset the surfacer only to mill off the high spots. This removed about 90% of the damage from the heads. I’ll post a picture when I get them back.
Well, I certainly wasn’t expecting to see this sight again for a long time! What happened you ask? Read on…
Here was one of the shots I took from the first run of the engine at the dyno shot. The owner of the shop encouraged us to run the engine without the air cleaner to really find out how much power it would make. If you look really close, you can see an extra nut on top of the shaft sticking out the top of the throttle body. That nut is installed to provide a backing surface for the upper half of the air cleaner (so the upper half is clamped between that nut and the outer wing nut). When the air cleaner is not installed, that nut is free to spin on the shaft.
Here’s one of the first shots of the engine after it came off the dyno; notice anything missing?
At some point during the dyno run, the vibration caused that nut to back off and get sucked into the engine.
It appears to have spent most of the last moments of its short life bouncing around the inside of cylinder #6. It caused considerable damage to the top of the piston which is what prompted us to pull the heads. While diagnosing the rough running engine, I borescoped all of the cylinders and spotted the damage. Although the nut was long gone, I couldn’t tell that without pulling the heads. My dad stopped by today and we pulled both heads in about 1.5 hours.
The underside of the head was pretty damaged as well.
Interestingly, there was minor damage in most of the cylinders, though nowhere near as bad as #6. This is the second worst cylinder and the piston doesn’t look anywhere near this bad (probably because it is forged).
We’re going to get some opinions on this over the next week. It seems likely we’ll need to replace at least one piston and at least resurface one or both heads.
I cut and installed the two pieces of tubing that connect the radiator to the engine. I’m not sure we’ll stick with this flex tubing, but it will work for now. I also just loosely zip-tied the coolant expansion tank to the chassis. We’ll be replacing this with a larger Canton Racing unit that we’ll order later.
The lower tubing snakes under the x-frame and steering rack before coming over the front sway bar and connecting to the lower left corner of the radiator.
After filling the engine with coolant, I test fired the engine and for some reason it ran surprisingly rough. It ran perfectly on the dyno, and there were only a couple of things we’ve touched since then. One of the concerns we had was that we could have cracked one or more of the spark plugs while removing and replacing the headers. I pulled them all and found them fairly carbon fouled.
Here’s the second one from the left in the photo above (probably the worst of the bunch). We knew that we were probably going to have to adjust the heat range of the spark plugs, but I’m still surprised how fouled these are for the engine being run for no more than 1.5 hours at the dyno shop.
I’m using the Breeze Automotive upper and lower radiator mounts which reduce the stress on the radiator flanges which apparently are prone to cracking with the factory mounting method. The factory had you bolt the upper flanges to these welded on pieces of square steel tubing, but they’re not necessary with the Breeze kit. I cut these off and then ground the upper tubing back to the right shape.
The hinge that is riveted to the upper radiator flange is then bolted to the cross bar. Then instructions have you drill and tap the square tubing, but that is pretty thin wall tubing, so I will probably just drill out these holes and use longer bolts with lock nuts.
The lower part of the radiator is supported with a smaller piece of square steel tubing that I’ve just loosely clamped on for now. The instructions specify this should be mounted at 51º, but I want to test fit the side aluminum before locking in the final position of this.
I ordered an upper and lower radiator mount from Breeze Automotive along with their radiator shroud. I centered the shroud on the aft side of the radiator and drilled three holes along the bottom edge. The bottom edge is only bolted to the aft flange of the radiator.
On the upper end, I drilled and riveted a stainless steel hinge to the forward flange. I then drilled a couple of holes all the way through both flanges of the radiator.
Using a couple of spacers, I clamped the front and back flanges together.
I didn’t get any pictures, but I bolted the transmission mount to the transmission with a stack of washers and some 2.5″ x 7/16″-14, grade 8 bolts. I also picked up some 1″ diameter, 6061-T6 aluminum rod to use to make some spacers once I’m sure of the exact dimensions.
I then tightened the engine mount bolts so the engine is hopefully locked in its final position. I won’t really be able to know until the body goes on and I see where it places the side pipes.
Jenn came out and helped me install the left exhaust header. It’s much tighter with the foot box in place, but not too bad.
The header comes pretty close to the rubber on the input side of the electric power steering motor. I’ll probably fabricate a heat shield to reflect radiant heat away from the motor and the rubber piece.
I also cleaned up the old gasket and reinstalled the water neck and thermostat bypass hose.
Finally, I reinstalled the air cleaner and breather cap. Once I hook up the radiator, the engine is ready to run in the car.
I jacked up the transmission and slipped the transmission support underneath and placed it on top of the aft chassis support. I loosely bolted the transmission mount to the top of the transmission support, roughly inline with the holes in the bottom of the transmission.
I then lifted the transmission up until it was aligned with the differential flange.
That creates a pretty big gap between the top of the transmission mount and the bottom of the transmission. I’ll need to fabricate some spacers that fit here.
Before measuring for the spacers, I wanted to make sure that the engine is level in the chassis. I measured the angle of the chassis and then adjusted the engine until it matched. I then measured for the transmission spacers. For some reason, even though the engine is level, the spacers are about 0.200″ different in height. I may just use some washers for now until we get closer to the end of the build and know the engine doesn’t have to be adjusted further.
I spoke with Tony at Factory Five today about the driveshaft issue. He suggested that the engine mounts could be installed backward, but I tried flipping them and I can’t see how they could be installed on the wrong sides. I took these pictures to send to him to confirm though. Here’s the right side.
And here’s the left side.
Since I’m not using a mechanical speedometer, I installed a plug in the hole at the left, rear side of the transmission.
I also removed the upper transmission fill port plug and added the transmission fluid until it started coming out the hole.
Finally, I replaced the crappy hose clamps in the hoses to and from the PCV valve with these much nicer ones.
We have a Halloween Party at our house every year, and it’s coming up in less than two weeks. I decided it would be fun to be able to fire up the engine at the party because I’m sure many people will be interested in the party. To that end, I’m going to hook everything back up as it was at the dyno shop along with the necessary additional bits to run the engine in the car (cooling system, starter, oil pressure and coolant temperature gauges, tachometer, etc.).
The dyno shop removed my oil pressure sender and hooked up their own hose to this extension. I reinstalled the sender and then hooked up a temporary pair of wires to drive the oil pressure gauge.
The dyno shop also installed their own coolant temperature sender, so I reinstalled my sender and hooked up the wires.
I also hooked up the engine ground strap from the right front engine mount bolts to the hole already provided in the mounting bracket.
To be able to start the car, I used some scrap aluminum to temporarily hold the ignition switch. I still need to wire this, but there are only a few connections to make.
I don’t want to start the car unless I can monitor oil pressure at a minimum, but it’s minimal extra work to also hook up the coolant temperature gauge and tachometer. I had considered fabricating a larger aluminum plate to temporarily mount the gauges, but the cardboard box they came in will work just fine.
I also set the fuel tank on top of the rear part of the chassis and hooked up the fuel lines. This has 4-5 gallons of fuel in it right now, so it’s fairly heavy. I’ll probably end up burning off a good chunk of this doing some demo and tuning runs. I need to get this lighter before I start messing with mounting this in the rear of the chassis.