Sunday, August 1, 2010

Seven engine rebuild (again)

Well after a disasterous start to the year, it was time for a new engine. The root cause of the failure was the lubrication system possibly caused by a blocked oil cooler.

I got a short block from Jem Engines, its a 711 crossflow bored out to 1700cc, with fully balanced internals. The engine is fitted with ARP con rod and fly wheel bolts. I reused the Kent 244 cam, and burton stage 3 head.

The first thing to do before building anything was to thoroughly clean the head, as the bearing failure had likely resulted in a lot of crud going around the engine, I stripped it completely and used pipe cleaners to go through each oil passage, and cleaned it with gunk degreaser and compressed air.

Afterwards I painted it black (it was blue) to match the block. I used hammerite and so far it seems to be doing the trick.

IMG_1406

Next was time to do the ARP bolts, Eric gave me some ARP Lube, so I torqued them up to 40 ft lbs.

SDC10137

I can build a crossflow in a couple of hours from memory alone now, I could even remember the number of degrees to set the cam to, although this didn't stop me from making a hash of it the first time and having to re-time the engine after everything was built up.

SDC10141

I used a competition gasket set from Burton, Eric recons the best way to get a dry seal on the sump is to evo-stick the gasket to the block, then use a little blob of silicon around the rubber seals on the end, and tighten it up gently.

SDC10144

I tried this, the result was an enormous oil slick on the garage floor after the first drive so I'm back to experimenting with silicon... The engine was back in the car in less than 4 hours, ready to start, or so I thought.

SDC10145

It fired up first time, but made a noise that left me clutching my wallet.



It turned out that the oil pipe was ever so slightly grazing the con rod bolt, this thankfully was easily fixed with a gentle tap from the hammer and it finally ran smoothly. Getting the sump off in-car is a real pain, however if I loosen off the engine mounts and replace the gearbox->engine bolts with longer ones, I can use a crow bar to seperate the engine from the box about an inch which is enough to get to the rearmost sump bolts.

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