Here you can see us checking main journal dimensions with an outside mic. The numbers you see are our measurements. Overall variance between all ... Show morejournals was .0005", from 2.2482" to 2.2487". We also checked the rods, but I don't recall the numbers and the build sheet is still with the motor. How do you guys like Brian's 'engine building' shirt?
The next step in checking main journals clearances is to measure the inside of the main bore with a bore gauge. Setting these up accurately is a...well...pain in the ass really. The measurements are only as good as your setup. Our measured clearances varied from .0027" to .0031" Although there was a small discrepancy with the go/no go gauge as you'll see below. Isn't that a great shirt Brian's wearing??
So this is an example of the go/no go gauge you have heard mentioned on this board and elsewhere. It's simply a piece of feeler gauge of a given dimension cut and flattened, then sandwiched between the bearing shell and crank journal. The journal is then torqued to spec, and an attempt to spin the crank is made. The positives to this system is that you have an ABSOLUTELY positive measurement in the feeler gauge, and once you have the system down you can measure to within a thousandth or so by feel alone. The negatives...well, it's a 100% subjective thing lol. I like to put a socket on a crank bolt, and choke up my fist so that I only have a roughly 5" grip, then turn the ratchet with my wrist. If it will not turn at all (with reasonable force), we insert a smaller gauge and try again. We use this as a check of our measurements, and it can really catch you if you slipped up. For example on this motor, our measurements were .0027" to .0031", but the go/no go said .0025" (and a tight .0025" at that), to .0028" tops. In order to even things out and give myself wiggle room, I'll polish the backs of the tight bearings and check again. That should give me my few thousandths clearance on the tight bores, and put me right within my preferred spec of .0025" to .0030".
Anyhow, there's my small update for today. Chances are I'll get down to work on it again tomorrow and hopefully get the shortblock mock up finalized. Who knows, if things go smooth with the rod bearings, we might even get the shortblock assembled =D. Maybe you guys will also be dazzled with more of Brian's innately stylish fashion sense lol.
www.peteandersonracing.com Show Less
Pete Anderson Racing So anyway lol. I got the piston to wall checked today, and it's a bit larger than my preferred specification of .005". Eve... Show moren though the difference was only .0015"-.002" (.0065"-.007"), and within my piston specs...I'll be taking this up with the shop. The pistons themselves are all within .00025" of 4.025". We also gapped all the rings as well...and I got a few pictures of that process. Show Less
And here is the top ring after being checked initially, and adjusted to its final spec of .021". The ring manufacturer calls for a dimension equal to th... Show moree bore x .0045", however as an added safety margin I always add more gap. It's a VERY small amount of power for a VERY VERY large margin of safety. If I was that concerned about the least bit of leakdown on this motor, I'd be using a gapless ring to begin with. Show Less
Pete Anderson Racing Well!!Motor's all together =D. I had a very large update planned...I'd taken a BUNCH of pictures, but apparantly Bria... Show moren set the resolution on his camera to 640x480...and none of them came out worth crap =/. I did get a picture of the finished motor this evening off my cell phone though!! Show Less