I wouldn't say that, but thanks anyway.

 

well, after I got home last night I sat down to review my measurements of the cylinder bores and select pistons.

as is par for the course so far on this engine, some of the numbers didn't meet my satisfaction.

after talking with my ever-patient machinist Billy Duke at Competition Engine Service here in Richmond, I realized what should have been obvious.

I mic'd the cylinder bores of the block properly, but when they were bored/honed, it was with a torque plate bolted onto the deck.

the purpose of a torque plate is to simulate the loads placed on the block when the cylinder head is bolted into place. while a block might seem like a solid unyielding chunk of metal, it will actually stretch or flex a bit with all of it's fasteners pulling in different directions.

so tonight instead of checking my main bearing clearances, I suppose I'll be bolting on the torque plate and rechecking my cylinder bore measurements.

it's hard work having fun guys...

later,
chris

 

Superfords, you should also leave the torque plates on when you file fit the rings to the bores. Also torque the mains on, the water pump and install a bellhousing (if you have a spare trans) to accurately distort the block to get the best ring seal. I see a lot of guys file fit the rings with the block just bolted on the engine stand, which won't give you the best ring seal. As you already know (others may not), anytime you can increase ring seal, even slightly, horsepower is always increased. You're a detail oriented guy, and its the little details that seperate the great engines from the also rans.

Just curious, why didn't you have any performance mods done to the crank? You could've had your machinist streamline the counterweights for less resistance in the oil mass and less rotating weight, and cross drill it for better oiling of the main bearings. For some reason most guys are using completely stock cranks, and leaving some power hidden in the bottom end.

 

rscoleman
The factory already took care of the crankshaft for you
Its got nice aero counterweights and is crossdrilled.

Also since the studs go to the main webbing in the block, I found the torque plate had its most effect on the lower part of the cylinder and Chris is right about the distortion, I saw as much as .0015 out of round but that was in the middle to lower part of the bore. The top side of the bore near the deck was round.
Dale

 

where did you get your torque plates?

 

torque plate from B.H.J. around $300 bucks.

 

as an update, I bolted the torque plate on and checked the measurements again, much better numbers, and since i like to double check everything, I bolted the torque plate back on again AFTER I had installed the crank shaft and the numbers were even closer! today didn't turn out so badly after all!

here's the torque plate (it simulates the cylinder head being bolted onto the deck of the block):


installed views:




and NO, before somebody asks, the green tape with the cylinder numbers is not there so I can remember which cylinder is which. I'm not THAT bad. it may be hard to see in the pic, but I was jotting the clearance numbers down on the tape so I didn't have to keep running back to my notebook.

later,
chris

 

That your shop at home?

 

nice bro

so uhhh, what blower are you putting on top of this thing and what psi are you planning on running? What kinda times are you trying to achieve?

 

and here is the dreaded crankshaft end play measurement. those of you who read the other thread will know that I screwed up my decimal point when I wrote my specs down and I thought I was WAY OUT on this one, but thankfully it was just a stupid mistake.

anyway, set your dial indicator up at a 90degree angle to the crankshaft, use a flathead screwdriver and GENTLY pry the crankshaft all the way in one direction (towards either the front or rear of the block) and then zero your gauge.



now push or gently pry the crank in the opposite direction and record your crankshaft end play measurement!


so far so good!

there are about 1 Meeelion more things that you could measure on this engine, but I think I've covered most of the critical measurements to the bottom end. it just depends on how accurate you want to be and how much time you have to spend "blueprinting" your engine. for me I think I've had just about enough measuring for this lifetime!

next step is to file the ring end gaps!

later,
chris

 

ha! I wish!


I'm going to be running this ported Apten with my 6lb lower. plus a 150 or so NX shot!

I'm hoping for a high 10. we'll see.

later,
chris

 

I was gonna say........nice setup at home. How much would a decently equipped shop run a guy? Building and all.

 

well i've been sick since this past Saturday when I put the crank in, so I haven't really made any progress on the motor.

tonight I started filing the rings to fit the cylinder bores.

let's just say it's not my favorite part of the job.

I bought a manual crank ring filer. I wish I had gotten the electric one, I feel like I need 3 hands to properly hold the ring centered and crank the thing at the same time.

anyway, here are some pics.

new ring in bore has about .01 end gap, too small.


so start filing:


then measure with feeler gauges...

and file some more:

 

grind a little and measure and grind a little and measure until you achieve your desired end gap.

the correct end gap is determined by your ring manufacturer's specs, your intended use (nitrous, boost, etc), and may vary depending on who you ask. too little gap and the ends of the ring will touch causing high friction between the cyl wall and the ring and maybe worse (BAD), too much gap and you'll have lack of power and excessive blowby (BAD). so it has to be just right.

you need to make sure that the ring is square in the bore by inserting it with either one of your pistons or a special tool. I just used a piston. the manufacturer of my particular rings calls for end gap to be measured with the ring about 1" down inside the bore.

when you're done your feeler gauge should fit in the gap with just a little drag like this:


hopefully I'll have time to finish all of the rings this week so I'll be able to install the piston/rod assemblies into the block on Saturday!

later,
chris

 

Chris, I gotta thank you, I swear I get smarter every time I read this thread....Keep it coming...