I'm rebuilding the 305 enigne in my camaro and want to know how important it is to messure the bearing clearance even though I'm putting in new crank and rods. Shouldn't it all just fit together without trouble since they are all new parts.

 

In theroy yes It should just fall togeather, but you need to keep in mind that EVERYONE makes mistakes, HUMANS & Machines, so anytime you build something ALWAYS ALWAYS ALWAYS go back behind and check everything.

 

bearings among other parts come in differant sizes, if you don't measure how do you even know what new parts to buy? yes it's important to measure everything, before and after.

 

well the kit I ordered is coming with new bearings matched to the crank, same thing with the rod bearings matched to the rods. Do I still need to check the clearance.

 

YES!!!!! ALWAYS check everything befor building it, it could mean the differance between a 1000 mile engine or a 100,000 mile engine.

 

did you order a new crank and bearings? if you never how do you even know what size bearings to buy, or if your crank is good with out measuring. there is no way to get around measureing the clearance, unless you just want to throw parts together and sodomize the assembly process and the end results.

 

Well what should I do if the clearance is off even if everything is new.

 

that all depends on how much its off..........

 

DO YOURSELF A HUGE FAVOR
buy these books, FIRST it will be the best money you ever spent, read them, and you will be miles ahead of the average guy. youll save thousands of dollars and thousands of hours once youve got a good basic understanding of what your trying to do!

HOW TO BUILD THE SMALL BLOCK CHEVEROLET by LARRY ATHERTON&LARRY SCHREIB

HOW TO BUILD MAX PERFORMANCE CHEVY SMALL BLOCKS ON A BUDGET by DAVID VIZARD

JOHN LINGENFELTER on modifying small-block chevy engines

how to build & modify CHEVROLET small-block V-8 CAMSHAFTS & VALVTRAINS BY DAVID VIZARD

SMOKEY YUNICK,S POWER SECRETS
SMALL BLOCK CHEVY ENGINE BUILDUPS


Heres a few ( ) things that should always be checked on an engine being rebuild

heads
are the pushrods perfectly strait?
do the pushrods flow oil?
rocker studs/guides torqued correctly?
do the head bolts have washers under the bolt heads? are they the correct length for the cylinder heads in use?
have the heads been pocket ported?
combustion chambers unshrouded?
intake ports gasket matched"
are the valve guides cut to the correct length?
are the heads pocket ported?
is the retainer to valve guide clearance correct?
are the valve guide oil seals installed?
is there valve spring seats installed?
inner damper springs installed?
spring bind height checked? (to exceed max valve lift by .050 min.)
oil return holes cleaned of casting flash?
were steam holes in heads necessary?
were the spark plug threads of a installed spark plug extending into the combustion chamber?
rocker slot to rocker stud clearances ?
retainer to valve guide clearances?
spring bind height checked for the correct spring pressure?
valve lash/preload ?
are the valve springs the correct tension,height?dia.
keeper the correct angle? style? size?
valve seats the correct angles?
valves back cut?
valves the correct length, stemsthe correct diam.
strait?
rockers the correct ratio?
were the valve to valve guide clearances checked?
were the heads milled?
did the head gasket overlap the bore?
what are your valve train clearances?
is the rocker arm geometry correct!
chambers CC,ed
port work..(some steps optional)

(1) open throat to 85%-90% of valve size
(2)cut a 4 angle seat with 45 degree angle .065-.075 wide where the valve seats and about .100 at 60 degrees below and a .030 wide 30 degree cut above and a 20 degree cut above that rolled and blended into the combustion chamber
(3)blend the spark plug boss slightly and lay back the combustion chamber walls near the valves
(4)narrow but dont shorten the valve guide
(5) open and straighten and blend the upper two port corner edges along the port roof
(6) gasket match to/with intake and raise the port roof slightly
(7) back cut valves at 30 degrees
(8) polish valve face and round outer edges slightly
(9)polish combustion chamber surface and blend edges slightly
(10) remove and smooth away all casting flash , keep the floor of the port slightly rough but the roof and walls smoothed but not polished.
(11) use a head gasket to see the max you can open the combustion chamber walls
(12) blend but don,t grind away the short side radias


block
is the oil pump pick-up mounted 3/8"-1/2" from the oil pan floor/
is the windage screen mounted about 1/8" from the rotateing assembly/
is the pick-up brazed to the pump body?
has the oil pump relief piston in the oil pump been checked for free ,easy movement? clearance? spring tension?
is the oil pump pick-up tube inserted too far into the oil pump body,(binding the gears)
has the block been clearanced for the rotating assembly?
has the block been aline honed?
is the crank strait?
are the damper install keyway and threads ok?
counter weights clearanced?
MAGNAFLUXED?
OIL PASSAGES CLEANED?
GALLERY PLUGS INSTALLED CORRECTLY?
has the cam to rod bolt clearance been checked?
piston to valve clearances checked?
piston to bore clearances?
TRUST BEARING CLEARANCE?
what were the piston ring to slot clearances?
RING GAPS?
were the rings all checked individually for end gap in the cylinders they were used/installed in?
were the rings checked to make sure the correct side faced up, and the correct ring was in each groove?
what were the back clearance on the rings?
were the oil ring expanders carefully fitted for correct drag?
were the oil ring scraper ring rails checked for end gap?
total cam lift and remaining clearanceS?
WAS THE CAM DEGREED IN?
main bearing clearances?
what is the main bearing run-out clearance
piston to head clearance? (QUENCH?)
head gasket to coolent holes checked?
magnets installed?
rod bolt to block clearances?
what tq reading is necessay to spin the crank with no rods attached?
are the rod bolts and main caps torqued correctly? (rod bolts checked with a bolt stretch gauge?)
did you check the block for a strait main cap alignment?
what size journals and what were the bearings edge to filet clearance??
are the journals checked for finish and run-out/tapper?
did you use moly lube to assemble?
correct bearing crush?
did you pre-lube before start-up?
did the distributor gear fit the cam gear precisely?
was the distributor oil flow mod done?
was the correct style distributor gear used?
did you check the piston to piston pin bores for fit and clearance?
did the piston pins to snap ring clearance seem overly tight?
if they are pressed pins were they correctly matched and checked for free movement in the pistons?
was the engine ballanced?
cam button installed?, and lock plate installed?
were the rods resized? checked for parrallel bores/were the rods strait?
piston valve clearance notchs correctly located on the pistons? edges smoothed?
were the rods checked for length?
is there a few thousands clearance on the oil pump drive shaft AFTER the distributors bolted down?
did you install a steel collar on the oil pump drive shaft?
was the rod to piston pin side clearance checked? (at 4 places seperated bye 90 degree spots)
does the oil pump drive shaft mid section clear the block with the pump installed?
whats the starter to flywheel gear clearance?
is the pilot bearing to trans imput shaft clearance ok?
is the front motor mount bolt to fuel pump pushrod clearance ok? did the fuel pump pushrod move easily/
are you possitive the pistons were installed with the correct valve relief in the correct location?(eiieeiie) were the pistons installed with the correct side facing forward/
what torque values were used on all fasteners/ were they the correct length and type bolts?
were the bores honed with a torque plate in place?
was the cylinder finish correct for the type rings used?
was the oil pump itself checked for free spin and clearance AFTER THE PICK-UP WAS INSTALLED?
was the cam drive checked for free rotation and drag/
were the oil passage plugs drilled for extra oil flow?
were the lifter bores checked?
cam to timing cover clearance?
cam journal to cam bearing clearances?
was the cam journal run-out checked?
was the cam degreed in or just lined up useing factiory index marks?
has the rod and windage screen to oilpan clearnce been checked?
does the dipstick & tube clear the windage screen?
was the cam lobes/LSA/LIFT CHECKED?
is the deck square/level?
whats the cross hatch hone angle?
what grit hone was used?
are all the threads clean/clear?
brass freeze plugs installed?
block painted?
do the oil return holes have screens epoxied in place if necessary
besides the normal checks for deck height, line hone,and splayed main caps, making sure all the threaded holes are correct, the cylinders honed lifter bores are correct, theres the little things, I paint the inside surfaces of my blocks with
http://www.glyptal.com/1209_black_enamel.htm
to lock in place any micro dust left after the last total cleaning before assembly, to speed the oil flow back to the oil pan and help prevent corrosion
BTW I bought 16 rubber corks to push into the lifter bores to prevent paint entering the lifter bores durring the painting, I placed 16 mini-screw eyes in the corks and strung them on a bead chain to keep from loseing them while in storage or in use!

http://www.camtattoo.com/camshop/hom...ing_Tubes.html





Ive used BOTH RUSTOLEUM (BRITE YELLOW) and Glyptal but lately just several coats of BRITE YELLOW RUSTOLEUM ON OVER THE glyptal EPOXY BASE COAT,COVERED BYE BRITE YELLOW RUSTOLEUM APPLIED ON THE TOTALLY CLEANED AND DEGREASED AND DRIED BLOCK, (BTW A TOTAL DEGREASE OF THE BLOCK WITH ACETONE,and LINT FREE CLOTH, AND A heat gun or hair drier to totally dry the block just before cleaning helps the paint get a firm grip on the block surface) and dont forget you should remember the option to J&B EPOXY a MAGNET in the lifter gallery BEFORE painting the surfaces if you want to permenantly afix it on the block. (which do a great job at picking up micro metalic dust)
http://www.wondermagnet.com/dev/magnet1.html


I buy and use the 1 quart size cans of brite yellow paint at the local hardware store keep in mind that YOU MUST ALLOW THE PAINT TO TOTALLY DRY BEFORE ASSEMBLING THE ENGINE, AND THAT NORMALLY TAKES A FULL DAY IN THE HOT FLA HEAT (85 degrees (F)is a fairly average temp here
#7747 Sunburst Yellow
http://www.rustoleum.com/product.asp...ct_id=18&SBL=1
I use brite yellow on both the interior and exterior of the engine blocks I build because it makes finding oil leaks very easy once the engines in use in the corvettes where space is cramped and finding small leaks can sometimes be a problemActually the idea is to grind away all casting flash (the rough sandy looking surface) from the inside of the block, and then wash thoroughly, dry thoroughly, then apply the paint. This takes a long time and must be done carefully which is why most engine builders don't do it, but engine builders on racing teams do it.

It's not only to assist in oil drainback but also keeps the oil from clinging to the block and coking. In racing engines the benefits are slight but noteworthy, http://www.sa-motorsports.com/blockdiy/blkdiy.htm

http://www.hardblok.com/info.html


http://www.speedomotive.com/building%20tips.htm

http://www.se-r.net/engine/block_prep.html

now in addition to that info , heres what I do
(1) get the block totally cleaned, DEGREASED and CHECKED by a GOOD MACHINE SHOP BEFORE INVESTING MONEY IN IT!
(2) have new cam bearings and freeze plugs , oil plugs,installed by the local machine shop if you dont have the correct tools,but only after all other machine work is done and after a extensive recleaning of all the oil passages just prior to starting assembly
(3) screens over the oil drain back holes are a good idea ONLY if your willing to change oil and filters very frequently
(4) several powerful magnets in the oil pan and one in the rear of each cylinderhead to trap small metal parts is EXCELLENT INSURANCE
(5) polishing and smoothing the valve edges and combustion chambers helps prevent detonation
(6) if your pouring the block,never fill the water passages higher than the bottom of the freeze plug holes on a street engine
(7) 7 or more qt oil pans with BAFFLES AND A WINDAGE SCREEN like MILODON MAKES are a GREAT IDEA
theres more but thats a good start?

 

i agree with DTL, you need to do more reasearch and prepare a bit more before you attemt to build or overhaul an engine. you lack some basic knowledge and understanding of the process and how parts work together. maybe you can find someone in your area that is experienced that could help you, or you could watch and help them to do the assembly.

 

You guys make it seem like I'm building a 700 HP monster. I'm building it to stock with all stock parts. The machine shop is taking care of the cleaning and machining of the block and possibly the rotating assembly depending on money. The rotating assembly is all new so I don't have to worry too much. The heads needed new valve seals, so I did that no prob. I'm getting new push rods so no biggy and maybe a new cam and lifters. Now its only the gaskets that I need to put everything together.

 

ok you don't really need to check clearances or fit up after assembly. useing a torque wrench is pretty much a waste of time too as long as you stick with a stock type rebuild. now that you have the answer you were looking for you can feel a lot more confident throwing the parts together and later on wonder what went wrong because it was only a stock 305.

 

Take this with a grand of salt:
Anybody get bolt a engine together and maybe get 3000 miles out of it. Checking and ensuring the engine is put together properly with all clearance check atleast three times is a waste. We as humans never have to do it right the firt time but we have the time to do it again after it throws a rod or pitson to valves interference cause the engine to perform very lousy. But its your money and engine so do what you feel is best for you. However don't post asking what went wrong with the engine when its not performing once you get it together, just review this post and you would find the answer. A lot of people post reply because of experience and problems that the have encounter in the past....
We are just giving advice, you make the decision...
HERE TAKE A LOOK AT THIS MAYBE THIS WILL HELP CHANGE YOUR MIND:

https://www.thirdgen.org/techbb2/sho...ight=scat+9000