carl.froehlich

Dear All,
I had disassembled the engine of my 95 Camaro Z28, 6 speed, 60 K miles, after head gasket failure.
The engine was STD and it will be bored to .020 (block). The crankshaft is OK and needs just polishing (.001 OS rod and main bearings keep the clearance inside the limits).
As I want a mild improvements I had bought the following parts:
Comp Cam 07-465-8 (260/270, lift .550/.560 at 1.5 ratio, 113, range 1200-5200 rpm);
Comp Cam RPM 1618-16 rocker arm, SA, 1.6 ratio;
Clevite SH1349S bearing cams;
Valve Springs Com Cam 26918-16, single, beehive, 372 lb/in;
Chevy Performance high volume oil pump;
The engine has a bored Throttle Body, 52 mm, without cat at the exhaust pipe.
I drive mainly in streets and I need good low and intermediate range. The engine is not for performance or racing, but as I want to get some fun, eventually it will reach the red line (5700 rpm) for a short period. The engine shall be reliable and last for a long time.
I’m thinking to buy hypereutectic pistons Speed Pro H631CP20 and piston ring set Sealed Power E-251K20.
As .001 OS rod and main bearings keep the clearance inside the limits, what kind of rod bearing and main bearing kit should be bought for the engine?
I don’t have enough knowledge to choose among the manufacturers’ options. King Engine has SI, XP, HP series. Clevite has H,P or V series and so on.
What is your recommendation for me, considering the purpose of the engine?
Other point is the valve train (STD, OEM). The machinist told me that the intake and exhaust valves are inside the tolerance ranges and they could be reinstalled again. I’m afraid about the extra charge of the springs on valves. What are your opinion about?
Many Thanks
Carl

RUDEDOG

At 60k miles I would re-install the stock pistons and rings and go with Clevite H series bearings. That's what I did at 90k and I'm at about 160k now and compression is the same if not better. Always running Mobile-1 synthetic and Melling HV pump. If you are using the stock heads I would send them to Lloyd Elliot port works for a port job and springs. I used AFR's. That's my experience. Check it out in my Signature.

carl.froehlich

As the cylinders are far away from the STD tolerances, they will be bored to .020. The previous owner probably didn't care about oil specs, cooling system or maintenace in general.
The heads are stock and they will be ported a little bit.
The bearings will be Clevite.
Thank you for sharing your experience.

97WS6SCharged

The P series bearings are Clevite's aftermarket replacement bearings. The H bearings are the higher performance bearings usually used with aftermarket cranks. You can use either.

Whenever I rebuild a motor I always opt for a dual valve spring just for peace of mind whether or not I'm using a big cam. Just personal preference. I also usually spend a few extra bucks for a good valve job.

I don't know what your goals are for the car exactly but that cam is tiny even by tiny cam specs. You might look into something slightly bigger such as the 305 grind.

carl.froehlich

I took a look on Comp Cam specs and the 305 is more agressive. Does it have a good low and mid ranges? The 07-465-8 has much less duration at .050 (210 int, 218 exh) and more lift (.56 int, 0.555 exh, 1.6 ratio). I'm not an expert, but high rpm or any improvements on heads don't match with this cam. As I had bought it with all recommended components (rocker arms, push rods, springs, etc), the only way is move to 07-466-8 (218 int, 224 exh at .050; 113 lbs; lift 0.57 int, 0.565 exh, 1.6 ratio).
Thanks

Chimera96

The 466 would be good, I have that cam. great low end TQ and makes good power. It is the next one up from the 465 in the XFI series. I pass Calif. smog easily with it and the idle is very mild.

Unlike other cam grinds the XFI series rates their lift WITH 1:6 RR so in comparing it to other cam lifts is not the same as those are based on 1:5 RR

You are correct in that Comp does spec 26918 springs. They are good springs but are a "single" spring if that is a concern. I am replacing my 918's with Lunati double springs as mine are getting tired after 30k mi on the 466 cam

Unless you are going to run wider than stock bearing clearances I would not us a HV pump. Just a stock pump with the GM "white" spring in it for more pressure. Good idea to go with a steel oil pump drive shaft from ARP or Meling

whatever pistons you get, keep your compression ratio around 11-11:5. The LT1 is not like a old SBC where 9.8-10.5 was the norm

typically .030 is what most bore to. That gets you a 355 CI motor. Your stock crank should be fine with a polish. If it needs a grind have the machine shop spec the .xxx over bearing size. Clevite H series is a quality bearing

stock rods are fine but many have them re-sized with ARP fasteners

Mild cam like a 466 or milder 465 is fine for a basically stock or mild ported head.

You will need to get the PCM tuned for the cam. It will wake up the car and should be a nice runner when you are done

There are some unique things to the LT1 vs Gen 1 SBC. Ideally your machine show is aware of them.

MachinistOne

Use a Durabond CHP-8 cam bearing set - it's a better one piece design and tougher material compared to the Clevite.

For main and rod bearings you should just stick with a P series bearing. It's a better choice for a non dedicated race motor without an aftermarket crank, stock fasteners, and rods because the eccentricity is higher allowing for more flexing of parts without the bearing pinching the crank. It also gives you added embeddability which is a positive for a daily driven motor.

Clearance wise, as long as your housing bores are in spec, and the crank is still in spec, even at the low end, you'll likely just want to use Std/Std bearings to add a little bit of oil clearance and end up at .0022-.0025 on the mains and .002-.0022 on the rods.

If you're doing a stock rebuild, just use the catalog piston that is specified for LT1 engines - it's lighter and uses a thinner ring pack than the one you're talking about with the old SBC 5/64" ring pack. The Sealed Power E251K ring is a bargain moly which isn't even as strong as the factory ductile top moly ring.

Really, you shouldn't be having to ask these kind of questions - bearing and piston/ring selection is something that any competent machine shop or engine builder should have down solid and be telling you what to do...