Che70velle

iTrader: (6)

If you had a Darton sleeved GM block, or perhaps a Dart…or another aftermarket block with Darton sleeves, you’d be much closer to hitting the cylinder with the rod/rod bolt. The reason being is that the Darton sleeves are longer at the bottom to help support the piston skirt at BDC, strictly for stroker applications in mind. While we are on the subject, how far are your skirts coming out the bottom of the hole at BDC? Just curious.

Double06

iTrader: (1)

Here is an example of the notch in the block for the rod this is a longer 4.125 stroke though. As Maxwell Smart would say "I missed it by that much".

slowride

iTrader: (3)

The reason he has more clearance is due to the larger bore block to start with. You will see a lot more clearance marks on a smaller bore blocks more often than not when using 4"+ crankshafts.

grinder11

iTrader: (1)

Thats what I thought. Thanks for clarifying..

65LSXNOVA

This is the 4th or 5th set of cam bearings ive installed on a LS in the past 25 yrs. I know the ch-25 are wider than the ch-23 but damn i think they could make the ch-25 even wider if they wanted.

Installation Using one of summits cam bearing installers. Works pretty darn good.

Finished product. Used a allen wrench and stuck it thru cam bearing oil feed hole to comfirm oil hole alignment.

65LSXNOVA

More bearing troubles.....started measuring bearing clearances and #1 cam bear i was coming up with .0035(not bad) #2 im getting .0005 and i confirmed it as i can get the cam to even attempt to go into cam bearing #2. I do have a brand new set of ch-23 here i might give a try.

slowride

iTrader: (3)

Watch for the scaring in the cam bearing bore at the top from the seam marks of the stock bearings. They dig into the block and cause a raised spot which can cut down your clearance.

65LSXNOVA

do you think it matters if the main caps are installed and torqued?

Double06

iTrader: (1)

How does the cam look? It appears in photo some wear but maybe just the photo.

65LSXNOVA

cam (239/247) is very good shape with low miles. Last October when I tore this SBE down the cam I was running a cam(232/234) that i suspected it was slightly bent as it had tight spots when rotating. I then pulled this cam(239/247) out and put it in block and it spun fine. I just pulled all the cam bearings back out to make sure I had installed them in correct locations. All was correct.
Only thing I'm thinking is maybe I need the main caps installed and torqued

gnx7

iTrader: (28)

Should be fun! What heads are you going to run and target compression ratio? We did an 11:1 91 octane 416ci LS3 with 100% stock LS3 heads/intake and BTR either Stg3 or 4 cam and it made 560rwhp thru a T56 Magnum, McLeod alum flywheel/RST and 12 bolt with 335/30/18 out back. It had crappy mid length headers and a crush bent 2.5" exhaust also. Customer then had the heads ported, ported the intake with rod mod, custom cam, redone exhaust with dual 3" mandrel bent and LOTS of tuning where it made just under 600rwhp. This is a C10 AutoX Optima Challenge truck! It now has a 9" rear IRS setup ($$$$) in it and a whole bunch of front end aero plus some more out back. High dollar evolution build of the entire truck that does well in the truck class for sure.

65LSXNOVA

heads are what came off the sbe 6.2 I ran last year which are tfs235 cathedral ports milled to 61cc. Shooting for 12.1-1

65LSXNOVA

Well I torqued the mains down and reinstalled the cam bearings with the same results. Can't get this cam or the factory cam to even start to go into the 2nd cam bearing. Guess I'm ordering new cam bearings. I've never had this much trouble with bearings in the past....wonder if quality control is nonexistent anymore???

slowride

iTrader: (3)

Could slip a bore gauge into it and see if it's more of a size or alignment issue. Try from the back side, I know it's on a stand, but it's aluminum so just take it off

65LSXNOVA

When going in this direction #5 easy #4 very tight #3 no go cam almost stuck.

65LSXNOVA

What other cam bearings are out there?? Seams like alot of BS in the past on here with people using ch-25 durobonds

gnx7

iTrader: (28)

I've had issues a few times with the cam going in. Just get the journals polished and it should slide right in.... that's what I did. Not a huge deal.

slowride

iTrader: (3)

Did you install 4 & 5 from the back? Generally there is taper on the block to help those two from the back. Maybe polish the crank or check for burrs on the edge you drove the bearing in on.

65LSXNOVA

#2 #3 #4 are all too tight
#1 #5 are close to perfect with .0035 clearance

slowride

iTrader: (3)

Did you happen to double check the part numbers? That would be a pain, but what are the odds that 1/5 are fine and the others are off? I guess you might have to pull the inner 3