For any newcomers to the story, I built a 1380cc street motor for my Sprite
that sounds somewhat like a Diesel since I first fired it up. A knocking
that doesn't sound like a rod knock, and isn't as severe either. Once the
engine is warm, I don't hear it with the top down. With the hardtop on, I
do hear it and it doesn't sound good.
Piston slap due to too-large a bore has been suggested as a possible
culprit. I did not check the bore diameter before I assembled the engine
because I did not have a tool accurate enough for this.
Today I pulled the head off. The bores look good, not scraping.
I want to check the bore size.
What tool should I use to check it, would good calipers be good enough? Of
course I could only measure right at the top.
If this wasn't enough of a problem, I also found that the head gasket is
blown between cylinders 2 and 3.
I specified the block be offset bored, but Vizard says for 73.5mm, this
isn't even necessary. The head was milled, the block was not (I regret that
now). I used a copper headgasket from APT. Some say that the Metro Turbo
headgasket is superior. Any opinions?
I plan to measure the thickness of the wall between number 2 and 3, does
anyone know what the minimum safe thickness is?
If the bares are within spec, the pistons will come out and I'll check the
wrist pins and bearings. :-(
Ulix (wish I had just built a stock motor with a 266 cam...)
|