Yea, cam and lifters look great and the crank is fine IMO.

I dunno man. I like having the forged slugs. With the heat it took to swell these forged pistons, I don't think a stock hypereutectic piston would have taken it and may have had a catastrophic failure. This motor has been in over 6 years and taken 36,000+ HARD miles of abuse.

 

#1 and #2 look like heat got to them. my #3 and #5 cylinder walls and piston skirts looked exactly the same way after i tore mine down. i also broke the ringland on #5 and melted the ringland on #3. mine was a stock gm untouched 5.3 on 14lbs boost on straight 93

 

I need some advice guys. Took the block to the machine shop today and he thinks he can get #1 & #2 smooth with a .005 overbore (4.035 total bore). Wiseco is the only manufacturer I have found with a 4.035 shelf piston. According to Wiseco the new pistons are the same as the ones I have with the exception of a new ring pack and coated skirts. Should I just buy two new 4.035 pistons and put the others back in or do a full 4.035 set? Would .005 larger on #1/#2 make that much difference in rotational force and cause vibrations?

 

sorry to see this. that sucks. Did you happen to clean the tops of first two piston's in this picture or is that how they came out. they seem really clean compared to the other two. other the other two on are really dirty up top? http://www.ls2.com/BigKID/370rebuild/IMG_4343.jpg

 

I did not wipe off the ring land area you are referring to. Those two, 6 & 8, had some oily sludge on piston face when I pulled the heads off and there was some oil in the lower manifold too.

 

In addition to the previous post/answer, all 8 pistons are discolored on the ring land area on the bottom thrust side of the piston. The two in the pic you can see (6&8) just happen to be turned 180* from all the others in the picture. I presume this is from oil in the intake track running down the cylinder and pooling on the rings after a shut down and cooks on the hot piston. The piston faces were clean except for that little bit of sludge I mentioned earlier.

 

Just got a call from the machine shop saying that .005 took the scratches out so time to order my 4.035 Wiseco pistons.
Speaking of ordering parts... what bearings do you guys like? The engine had ACL main and rod bearings but it seems the King and Cleavite H-series are more readily available at the parts houses.

 

I got the block and crank back from the machine shop so all I need are bearings then I can start on the shortblock assembly. Machinist says to use a standard size bearing. It had FM main and ACL rod bearings previously. Thinking of going ACL or King all around. However, FM's are readily available and some builders on here swear by them.

 

Doing some calculations this morning and I am at a crossroad with my injectors. Looking back at some old logs, I was at 92% duty cycle at 6200rpm. The new heads/cam setup will have a recommended shift point of 6800 and will require a bit more fuel than the previous setup. I am sending my 60lb Siemens injectors to FIC for testing and rebuild anyway and was going to have them upsize them to 80lb. I am wondering now if 80's (92lb@58psi) will be enough. According to the calculators, using a .8bfsc, 900chp and 80%dc, I need 112lb/hr.

 

I skipped out on watching football Saturday and spend the day out in the garage pre-assembling the short block and measuring clearances. All of the main bearing clearances look good at .0025-.0028 with standard size King SI bearings. However, the bores are a bit larger than the machinist told me they were. I measure .0065-.0068 piston to wall clearance. Pistons are Wiseco 2618 alloy 4.035 bore with coated skirts that I measure at 4.0320. Sales rep recommended .0040 clearance when I ordered the pistons. I am going to call their tech line today and see what they say.