Brokenls

I think its time to admit defeat on my 5.3 build. I got the motor used, took to machine shop and had it bored .020 over, polished crank, cam bearings and heads done. I assembled it, used plastigage on bearings, rods in spec, main bearings were on the tighter side of tolerance but ok, i dont remember exact number. I put a btr truck cam in. I didnt know it had to be tuned for cam, so it did not get a 20 min break in cause it didnt stay running. I swapped factory cam back in. From day one oil pressure has not been great, around 40 on start up onced up good, around 10 at idle. I have checked with mechanical guage. I have done 3 oil changes so far, cut filters open, no chuncks just some glitter. I swapped in melling high pressure pump and a new oring. Pressure is a 45 accelerating, but still 10 to 15 at idle. Seems to have a slight tapping noise, i unplugged each plug wire to try to isolate it but made no difference. I am assuming main bearing issue, any other thoughts?

Brokenls

Motor has less than 1000 miles on it since rebuild

Brokenls

Could it be issue with barbell in the rear

ddnspider

iTrader: (26)

pinched o-ring on the oil pump could do this, or the barbell, or a leaking cover, etc.

Brokenls

Oring on oil is pump is good for sure. There are no oil leaks visible anywhere

ddnspider

iTrader: (26)

You can have internal leaks on the front and rear covers. How do you know you have the or-ing right? Is it the right size? Is the pressure gauge good.

Brokenls

I checked pressure with mechanical gauge above oil filter. Have put on 3 new oring on pick up tube just to make sure. Is there a way to check pressure at the front

Brokenls

Also put new cam retainer plate on

KCS

iTrader: (20)

Did you check the pan to pickup clearance?

Brokenls

No I did not. Last night I pulled trans and put in New barbell and gasket ask we will see

cookseyb

BTW with roller lifters you don't really need a 20 minute break in like flat tappet requires. BTR cam should be fine..For added "O" ring dimension and reliability read the instructions and use the proper color supplied by Melling and get the extra hold down bolt by SacCity Corvette for added comfort.

cookseyb

PS depending on the year of the engine there are three different cam bearing dimensions-sets, make sure they used the correct set...

Brokenls

Well put in new barbell and rear main gasket, running 42psi at idle once warmed up. Barbell was in tact and did not seem damaged

cookseyb

Great!!