# Making progress on my motor!



## NYH1 (Feb 20, 2010)

As some of you guys know, I'm building a mild 385 stroker motor, 4.040" bore x 3.750" stroke. Some of you guys have been a BIG help. So thank you to everyone for all of your help. 

Last week I clearanced my block so I had enough clearance between my rods and the block. Before I did any grinding at all, I could completely rotate the crank with all the rods and pistons moched up. I had no interference at all. However I didn't have the required .060" clearance between the block and a few of the rods. I only had to grind a little bit off the block down by the cylinders (#2, #4, #6 and #8). My crank and rods didn't come close to the oil pan rail at all. There was a ton of clearance there. I'm using a Scat rotating assembly. The crank is pt# 9-350-3750-6000 and the rods are pt# 2-ICR6000 (6 inch rods).

Today my cam and timing chain set came from Summit. The cam is a Lunati Voodoo 262/268 hydraulic flat tappet cam. Spec's are 219/227 dur. .050", .468/.489, LSA 112°. I moched the block up with the crank, rods and pistons along with the cam and timing chain and gears to check the rod/cam clearances. I didn't degree the cam in. I'll do that upon final assembly. I just installed it at zero on the timing gears. I installed one piston/rod set up at a time and checked the clearance between each rod and the cam lobes. I had more then enough clearance. Way more then the required .050". The rods didn't even come close to any of the cam lobes. I was surprised. The rods are stroker rods with cap screw bolts, but I was expecting to have to grind a little off of a few of the rods.

I checked my deck height on every cylinder today too. I checked them at each side of the piston in the same direction as the wrist pin go's to minimize piston rocking, which I didn't eliminate completely. The deck heights were .008" to .012". Again, I had a little piston rocking.

Next I have to file fit a complete cylinder worth of rings, top, middle and oil rings so I can get the rotating assembly balanced. I'm also going to take the cam bearings out so I can completely clean the block again.


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## NYH1 (Feb 25, 2010)

I measured my pistons yesterday at room temperature (70°). They measured 4.036" ± .0002". The smallest one was 4.0358" and the largest was 4.0362". 

My father and I measured the cylinder bores tonight. He set the temperature in the garage at 68° this morning before he went to work so everything would warm up by the time he got out of work tonight. They measured 4.040" ± .0003". The smallest was 4.0397" and the largest was 4.0403". I'm putting the smallest piston in the smallest cylinder and the largest piston in the largest cylinder. That gives me a piston to wall clearance of .004" ± .0001".

Keith Black's recommended piston to wall clearances for their FHR forged pistons as follows-
Street Normally Aspirated .0025" to .0035"
Street Towing .003" to .004"
Street Nitrous or Super Charged .0035" to .0045"

I'm glad my clearances are .004". Now I can put a 75 or 100 horse hitter on it down the road. I'll file fit the ring end gaps for this as well.

So far so good!


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