Tag Archives: head

Engine Carnage Revealed

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Recall my recent post about the untimely demise of my MR2 Spyder’s engine during a brief track weekend.  A recent visit to the guys down at DDPR gave me an opportunity to see exactly how bad the engine was damaged.  I’ll let the photos do the talking.

Damaged cylinder head  Damaged piston top Damaged cylinder wallBroken valve stem tipIn this last photo you see the broken off tip of an exhaust valve from the #1 cylinder.  It broke right at the retainer and looks as though it was a material failure.  Lesson: probably shouldn’t rely on used OEM parts in an engine producing 310hp to the wheels out of 1.8L.

The cylinder wall, close to the top of the deck is damaged from the loose valve head.  There’s also some scoring in another cylinder, could possibly be from particulates being injected into the oil during the destruction going on in cylinder #1.  Obviously the combustion chamber of the guilty cylinder is badly damaged on both the head and piston sides.  Looks like a set of 10.5:1 pistons are in order, which should also help to reduce EGTs and also allow running slightly leaner mix as detonation wouldn’t be as big a concern.

Fixing the Moroso pan, head rebuild.

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UPS has said the check is in the mail, hopefully that’s the case. Alright, let’s try to get back on track here.

90. Time to fix those craptastic Moroso drain plug threads. Picked up a knock-off Helicoil kit, which was probably a bad idea. After ruining every insert but two, I finally got it threaded in. Inserted the QwikValve with some of my favorite Permatex High-Temp thread sealant and prep (the only stuff I trust now.)
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/Moroso_helicoil.jpg[/IMG]

91. Stripped down a head with some aircraft stripper, thoroughly cleaned everything:
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/clean_head.jpg[/IMG]

92. Here’s where all the parts went. Every valve was cleaned with a 3M scotchbrite wheel. Replacing all the stem seals.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/head_parts.jpg[/IMG]

93. The intake manifold had a coat of sound absorption paint on it, which may have reduced its heat transfer somewhat, but it looked terrible and was starting to flake off. I took some more aircraft stripper to it… which ended up being nearly the whole can. That paint just turned to a nasty tar like sludge. After a lot of work I finally got it clean. I also sanded down the casting seams, cut off the unnecessary vacuum port (cruise control) and also cut off a few other aluminum protrusions. There was a bad dent on one of the runners, which I’m filling with JB Weld, then sanding smooth. I’ll eventually coat the whole thing in an epoxy based silver paint.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/IM_cleaning.jpg[/IMG]

94. I noticed that the Rotrex outlet line was competing for space with the fuel line, so I unlocked the fuel hard line from its plastic mount and pushed it into the tunnel. Then I drilled, and mounted a nutsert so that I could secure the SS fuel line with a cushion clamp to the firewall. The SS line was rubbing the paint on the firewall, so I ordered up some large heat-shrink and covered the line with it.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/fuel_line_clamp_heat_shrink.jpg[/IMG]

95. Also competing for space was the Rotrex and the wires/fuel line/vacuum line running across the front of the engine compartment over the right hand side. To help reduce the clutter, I decided to remove the the 4ga cable running from the remote jumper terminals to the battery. Instead I just shortened the cable and ground to a factory lug directly below the terminals. Saved space and weight all at once. A ohmmeter confirmed I had a good ground.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/remote_terminals.jpg[/IMG]

96. I also decided to swap my Aeromotive Compact EFI AFPR for a Radium Engineering unit, which uses Bosch OEM style non-adjustable regulators. More info on it here: [URL]http://www.radiumauto.com/products.php?Universal-Fuel-Pressure-Regulator-12[/URL] Very high quality gear, and good customer service. Since the FPR is set at my desired pressure, I didn’t really need a visual gauge, so I got a electronic pressure sender. Its cable run through the passenger side firewall grommet, then over to the Dataloggit so fuel pressures can be logged.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/Radium_AFPR.jpg[/IMG]

Engine tear down and cleaning

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Well I decided to bite the bullet and just build up a new(er) engine. I got a good deal on a new short block which should get here this week. I have two complete engines already that I’ll be picking and choosing the best parts from, and of course putting new gaskets on everything.

87. Old engine on the stand, with the head removed. Everything looks to be good on the engine. Cleaned up all the mating surfaces, got all the needed components off of it, and will probably sell the short block.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/old_engine_on_stand.jpg[/IMG]

88. My old engine had several layers of paint on it, both blue and black. I haven’t been pleased with any of the store brand spray on engine paints. They all claim to be chemical resistant, but everyone of them has started dissolving after just oil, gas, and simple engine cleaners. So I decided to use some G2 epoxy paint, the same stuff on my calipers. It is good for 900F and has stood up to brake cleaner. In order to get good adhesion I need to strip everything down. I started using brake cleaner, stripping pads on the air tools, and a lot of work with a wire brush. I then got some aircraft stripper, and just started coating the parts with it. This stuff is no joke, I had to wear two pairs of gloves as it just kept burning through. It doesn’t feel too hot when it hits your skin either.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/stripping_parts.jpg[/IMG]

89. Here are some of the parts laid out after initial cleaning. I quickly ran out of table space in the garage, so I picked up a cheap door at Lowes and put it on some saw horses for a make-shift work bench.
[IMG]http://strikewarn.com/uploads/spyder/images/Rotrex/Rotrex_TX/clean_parts_laid_out.jpg[/IMG]

Next up I need to break down and clean the two heads I have. Not sure which I’ll use, whichever appears to be in the best shape.