Common engine assembly errors - and how to avoid them

[Screaming Metal]

OK....been busy folks....back to the Article at hand.
When you put your distributor in, pay attention if its sitting up off the seating surface. If it is, this needs to be addressed. Its usually the shimming of the distributor, but this does affects your oil pump also, because its driven off the distributor. Reshim it, to keep all the wear off your housing and putting crap into your oil.
I use magnets in my oilpans and lifter galleys, to keep the wear to a minimum. Cam buttons are cheap. When that cam walks forward, it affects your distributor timing....check for this also.
Find the lowest hole you can in your water jackets, and use that DRAIN PLUG every few years get rid of that old antifreeze. Try the Evans waterless coolant. Keeps corrosion down. Better and easier on those radiators.
If you have the room, put on a remote transmission spin-on filter. All that trans line and the extra filter capacity adds cooling capacity to your trans setup, plus you can keep your trans clean by replacing that filter when you do your oil. No, not every oil change, I do mine about every 3 changes....that slippage and stalling puts minute traces of stuff into your trans fluid. A high stall will need it more, or a motor with alot of torque. Thing is, you can do it without pulling your trans pan off every time. I put studs on my pans, makes aligning the gaskets easier.....and the B&M trans drain plugs, makes it easy to drain those pans. I also silver soldier then into the rear end covers, makes adding and checking fluid easier.
When priming your motor, don't prime too long, you'll wash your assembly lube off things, You want oil almost there or there, not pumping oil thru the passages washing the lube off your cam lobes and lifters and bearing surfaces. Don't pack your oilpump with grease. You can stop up some of your passages and starve something for oil. If you MUST do this, use the white assembly lube, it will mix with the oil, and go into the pan. It will still help your motor break in.
Always doublecheck the machine shop, make sure the cam bearing oil holes line up with holes in the block. Those old WD-40 straws are good for these things, bend a 90 into the straw and make sure there is a hole there.
When your filling your motor with coolant, tale your Thermo housing off, pour water/coolant in slowly. When it just under the thermostat , plop the thermo in and seal the housing. This helps from getting those air pockets in the water jackets. Then, top off the radiator. Crank the motor, and have it idled up where the rings and cam can break in correctly. Vary your speed ever so slightly for the 1st 20 minutes, I let mine run for 30, and keep your eyes on everything.
I screw in a pressure gauge into the oil fitting hole there by the distributor, to keep my eye on things. They sell these small ones cheap, that are used on stationary motors and tractors......

 

[Mike]

And if you're shimming the distributor, use the proper shims. Don't try to stack extra gaskets on, as they will become oil-soaked, soften up and you'll suddenly find your timing is out in left field.

Final round of LeGrandnational, back in 1989. It looks like we're about to be off to a heckuva race, but the truth of the matter is that we got in a hurry at a previous race and stacked some distributor gaskets to shim things up. And the motor was shooting ducks, sitting there on the starting line. <sigh> Just another way to lose a race.

 

[Screaming Metal]

And if you're shimming the distributor, use the proper shims. Don't try to stack extra gaskets on, as they will become oil-soaked, soften up and you'll suddenly find your timing is out in left field.

Final round of LeGrandnational, back in 1989. It looks like we're about to be off to a heckuva race, but the truth of the matter is that we got in a hurry at a previous race and stacked some distributor gaskets to shim things up. And the motor was shooting ducks, sitting there on the starting line. <sigh> Just another way to lose a race.

Dam Mike, seeing that T Altered lifting its left front wheel and getting up on its bars, I figured I'd see the slicks on your car wrinkle wallin' getting ready to put the hurt on him! How much of a handicap?

 

[Screaming Metal]

And since the alum. distr. housing sits in a cast block the majority of the time, put a little anti-seize on it. I've seen these things get frozen in those holes before.....its almost like magic! Like MIKE said! DO NOT STACK THOSE GASKETS! Wrenching down on those dist. housings while they're up in the air will lock the dist up, bind the oil pumps, mess up your hi-dollar electronic distr., I have even seen them crack the distributor cap. When all that stuff stacks up solid, when you go wrenchin' down on it, it rises even more.
On your carbs on your cars when you start it to break the cam in, make sure ALL THOSE LITTLE VACUUM LINES ARE PLUGGED! I've been called into a shop because a motor is running like ASS, and its a small vacuum leak. THATS what they make inspection mirrors for! So before you go twisting on all those adjustments, make sure there isn't a missing cap somewhere.
If your car backfires, even if its a mild motor, look at your carb and make sure all those vacuum caps are in place.
I was once at a Nationals meet, under the hood of one of those big 800 Cu.In.+ Mountain Motors, it was blubbering really bad, it spit back, I had my head turned looking in one of my tool boxes, and was smacked in the back of the head by one of these small projectiles.
Backfires, being out of time or lean pops will send those caps flying.

When you first start a motor, check things 2, even 3 times, a overlooked detail can cost you a new motor. Make sure all your fluids are in there, are the right weights, theres coolant in there, all the bolts are tight. Get it to where its almost dead on so to start without a lot of cranking. If you've done this a few times you know what I'm talking about. Once you start her, its best to keep it going.
If your running one of these roller cams, you really won't have a breakin period, but if its flat tappet, or anything else BUT a roller, you've got a break-in. Once that cam has been run in to those lifters, everything has to be put back in its original positions. SO, if you have to pull things partially down got some reason, those lifters gotta go back into the same holes or you'll wipe your cam out.

For the guys on the early motors, when your putting those head gaskets on, make sure you pay attention to your coolant passages, Some gaskets restrict coolant flow, if you don't watch for details, some of these gaskets are made to go on one way. And if they aren't put on that one way, they will block a coolant passage. This is very important on the flatties, and the early model V-8s.
Sometimes I look at a coolant hole and its almost 1/2 the size of the hole in the block and head, so I open it up. Gotta be careful here.

Take your time during your rebuild and pay attention to details....

 

[Screaming Metal]

One, The 1st and most important gauge the a mechanic and tunes needs on startup, is a oil gauge. I screw it into where-ever, so I can see what the pressure is when she starts and how it holds while running.
The only gauge in most top fuel diggers or altereds? The lowly oil gauge, without oil pressure, that expensive motor is trash.

Save your old exhaust manifolds or headers, use them for startup. I'm pratically deaf, well, I have a really hi-pitched whistling in my ears because I worked in racing my whole life. Those headers and old headers will do 2 things.
Allow you to tune your motor without burning the chrome off your headers or turning then blue, and will get those exhaust outta your face thus the noise also.. DO NOT RUN A MOTOR WITHOUT SOME SORT OF EXHAUST MANIFOLD OR HEADER IN PLACE! You can damage it, or worse, catch something on fire!
I've lit myself on fire a couple of times being around the zoomies....it doesn't even alarm me anymore, I just swat it and put it out.

 

[Youngster]

Great thread guys! Thanks to all who are contrubuting.

Ron

 

[Keeper]

Great thread guys! Thanks to all who are contrubuting.

Ron

Agreed, this has already saved me hassle as there were a couple I missed!

Here is one I got from my machine shop.

Put a bit of ATV on the harmonic balancer keyway when installing. He told me oil likes to walk out that little key way if you do not.

 

[Screaming Metal]

Agreed, this has already saved me hassle as there were a couple I missed!

Here is one I got from my machine shop.

Put a bit of ATV on the harmonic balancer keyway when installing. He told me oil likes to walk out that little key way if you do not.

Well, I guess if you had alot of base pressure, like in a bracket motor where you just throw in a mushroom tappet cam and a Victor Jr. intake, a 750 dual feed double pumper with some 5.13's out back with a mid-sized car.....

Your Harmonic balancer usually is pretty well protected, oil has to fight its way past the lower timing keyway, then on some motors, past a spinning baffle, then past the key in the Harmonic balancer (clearence less than .004), then the flat thick washer on the end of the crank snout, that bolt usually torqued to 65+ ft. pds.......if theres a leak at the keyway, well, thats some might determined oil! hahaha.....
Guess its a good place to help seal, I've never had a leak there....but I would not say it couldn't happen.
And on top of it all, you have centrifugal force of that crank spinning....

Thing is if you have your PCV system set up to where you have a good vented system.... you'll probably be pulling a vacuum everywhere thats loose....I prefer to have that oil vapor inside my motor than out. I absolutely hate oil leaks!

 

[Lee_in_KC]

Put a bit of ATV on the harmonic balancer keyway when installing. He told me oil likes to walk out that little key way if you do not.

LOL, I had that happen to me. Soon after I got my T on the road I noticed a quarter-sized oil puddle on the garage floor under the front of the engine. I looked under the car and could see a tiny drip hanging from the bottom of the lip on the back side of the lower blower pulley. I thought, how in the world can oil come out there? I de-mounted the pulley and found a puddle of oil in the center bolt recess on the front of the crank hub. I pulled the crank bolt and area washer and found the back surface of the washer and the matching surface of the crank hub wet with oil. The bolt hole in the crank snout was dry. Again I thought, where in the world is that oil coming from? I pulled the crank hub off to check the seal in the timing cover, thinking somehow oil was getting past the seal and into the crank hub (probably impossible in hind sight). The keyway happened to be positioned at the bottom of the crank snout at this point and it didn't occur to me that could be the source. As I was sitting there staring at the crank snout trying to imagine the possibilities, a tiny drip of oil dropped out of the keyway right in front of me. Aha! I found you, you little booger! Cleaned up the key, keyway and snout with carb cleaner, put a dab of RTV in there, put the hub back on, and viola! No leak!

 

[Screaming Metal]

Dam Guys! I learned something today! I've been doing this all these years and I have never run across that! Hey, I'll start doing it! A lower blower pulley puts alot of stress on a balancer, thats why alot of places frown on running a stock harmonic balancer. I've seen the belts get adjusted a little too tight, that belt gets to slapping and snaps the end off on of those cranks. I always tell folks run it a little too loose instead of too tight, dam things got cogs on it, it ain't gonna slip....
I saw one guy did all the right things, except for that, he pulled his car up into the shop after getting it outta the car hauler, he rapped it coming thru the doors, and I saw that outter ring scoot forward, then a second later, there were all kinds of rotating mess all up in that radiator!

Anyway, if and when your dressing up your motors and you have those lovely new chrome valvecovers, keep your old ones for when you happen to need to adjust your valves. I adjust mine static. All my motors I run on the street personally are solid lifter rollers, so, I cut the tops out of the stock valvecovers that way I can crank the motor and doublecheck things while its running, just slide my feeler in there make sure everything is fine. Then I shut it down, let the oil drain back into the pan and cool, then stick on the nice ones.

And for the folks just starting your motors, always run a aircleaner. If you have a belt driven fan, that fan can blow air across that front airhorn on your carb and cause a miss....plus if theres a backfire thru the intake, it can save your butt....

 

[Mike]

For guys like Lee, who are running a blower, machining the crank for a second keyway can save a lot of grief down the road.

 

[RPM]

For guys like Lee, who are running a blower, machining the crank for a second keyway can save a lot of grief down the road.

I bought the Eagle blower crank when I built my motor, it came with the double keyway cut in it. I think it was only about $15.00 more for the second keyway.

 

[Screaming Metal]

I bought the Eagle blower crank when I built my motor, it came with the double keyway cut in it. I think it was only about $15.00 more for the second keyway.

Mike and Ron are correct, its best to go with a double key. Driving that blower takes about 50 horses....let me also give ya'll a few other numbers to think about.
A stock crank is good for about 400 to 45o horses on a smallblock chevy. 5oo horses on the bigblocks. Anything above those numbers and stresses add up quick, meaning, at any time, you can have a mishap.
A blower can give you a 55% increase in power, if not more, in some instances. The more boost you run, the more horses you have.
I'm around these things daily, and just throwing on a Summit kit, and if its anywhere near right, timing and carb wise, is enough to shred a standard bottom end. Unless you back off on the boost. A smallblock will probably be easily 470 horses with about 6 psi, and 550 @ 8-10 psi if not considerably higher....A little food for thought.
On a mild built smallblock, you can run a stock cast crank if all your gonna do is putt around town and have it only for looks, never getting over 3800 rpm and about 5 lbs of boost.
IF, IF you hang a foot off in it, a small 4-71 with a single 4 bbl will greatly surpass that safety margine, if the crank don't give up its ghost, the rods most certainly will shortly.
So, if your gonna get a blower, spend a few dollars on a good steel crank and some good steel rods.....they don't cost that much more. That extra couple of hundred dollars will give you the piece of mind that your lower end can handle that blower should you decide to run her on up to 5000 or 5500 to scoot around that early model 'vette thats been screwing with ya on cruise night.

 

[Lee_in_KC]

For guys like Lee, who are running a blower, machining the crank for a second keyway can save a lot of grief down the road.

Unfortunately, I had already gotten my motor built before I learned of the second keyway idea. Didn't want to tear it down just to do the key way. So far it's held up for five seasons. I had the crank hub off of it last fall just to check the key and key ways, and all looks like new. The crank hub fits very tight, so I'm hoping that will help. I'm running 1:1 and about 6 pounds (at 5000 rpm!). I've only seen positive boost on the gauge a couple of times when I did full throttle burn-outs. Otherwise, I baby the motor most of the time. Crank is GMPP forged.

 

[Mr T Bucket]

I did full throttle burn-outs.

Yes, he did.

 

[Lee_in_KC]

Yes, he did.

I believe you and Kevin did a couple yourselves!! And we were still using the e-brake at that point 'cause we couldn't get a pedal on the main brakes (turned out to be a bad m/c). LOL, good times!

 

[Mr T Bucket]

Yeah, but those were nothing like the last CowTown T meet burnouts down the street from my house last summer.

 

[Screaming Metal]

Unfortunately, I had already gotten my motor built before I learned of the second keyway idea. Didn't want to tear it down just to do the key way. So far it's held up for five seasons. I had the crank hub off of it last fall just to check the key and key ways, and all looks like new. The crank hub fits very tight, so I'm hoping that will help. I'm running 1:1 and about 6 pounds (at 5000 rpm!). I've only seen positive boost on the gauge a couple of times when I did full throttle burn-outs. Otherwise, I baby the motor most of the time. Crank is GMPP forged.

That crank hub fitting tight is a BIG+! As long as you got a good key in there, the nose angle on the balancer is tight when you torque it down, and the Blower drive pulley fits tight, your good in your case. Only using it every once in a while @ 6psi, the horses are there when you need it, should you need it.
I like to see the boost gauge come on when your really stepping on it up around 4ooo rpm and up, where the motor can take it. A single key can live under those conditions. Now, if you hammer on it pretty good fairly often, you'll start eating that crank nose up.
Like I said, a good crank and a good key are key components. Not all keys are the same! Have you ever taken a balancer off and 1/2 way down the key it looks like its offset slightly? Its partly sheared, need a new key. Its a safety feature, it's made to shear under a certain amount of stress.
On single key applications, you clean the balancer out with acetone and a stiff bristled brush, wipe the crank snout down, then put a little loctite on that nose put her on and torque her down.
Now when you take it off, your gonna have to get that balancer warm, smack it a couple of times with a hammer, before you put that puller on there or it'll never come off! Its called the right tool for the right job....

 

[Screaming Metal]

One last thing that needs addressing....I've seen all kinds of mess with oil pumps and the pickup tubes. Now, I'm open to new ideas, I play sometimes with motors trying to get a little extra outta them.
When you get a new oilpump, before you use that old pickup, look at your screen. Make sure its not stopped up. Also, make sure that the pickup fits in the housing TIGHT! Don't just wiggle it in and call it good.
If its stopped up, soak it in some solvent and blow it out good. If the screen is cut and tore, replace the screen and soldier a new one in place or replace the pickup.
I take the time to cut a couple of little braces that will weld to that pickup tube, then bolt to the pump body.
On the stockcars, sprintcars, we have the braces that tack weld the tube, then bolt to the pump or do the tack and the braces, both. Been in the middle of a heat race and seen them loose oil pressure because a pickup came loose. I've seen these tubes come out, even in stock motors when the fit isn't right.
Theres a art into putting them in too. A open end wrench that just barely goes over the pickup tube, and fits good against that bulge that bottoms out on the pump body.
Put a couple of pieces of wood on either side of the oil pump and tighten in in a vice. You want to compress the wood and not crush your new oilpump. Place your pump so that when you drive the pump tube into the pump, the blows are directed toward the rear jaw of the vice. Make sure the tube has a little chamfer on it, put a drop of oil on it, start in into the hole. Get your open end wrench, and the open end over the tube, side of the wrench jaws against the that bulge, and smack the wrench as close to the tube, right at the edge of the wrenchface as you can get. Hold the other end of the wrench, and have a rag wrapped around it. Otherwise, you will hurt your hand.
Since I do it all the time, I have a piece if tubing that is just about .005 bigger than the tube, I notched it out, weld a slug in the opposite end and I drive them in with that. A lot simplier, since I do alot of them.
Then, make sure that pump spins freely.
And for the folks that don't know, don't go messing around with your pumps springs and shims unless you know exactly what you are doing. If your doing a performance rebuild of your oil pump, do just as the book tells you.
Above a certain psi, that spring will hold a steady pressure by opening at a preset psi, to keep from twisting the shaft off, blowing oil lines off and filters apart. Putting a lighter spring in or taking shims out can lower your oil pressure. Putting them in can cause too high a pressure also, which in some instances, can be just as bad....

 

[Lee_in_KC]

Yeah, but those were nothing like the last CowTown T meet burnouts down the street from my house last summer.

Oh yeah, I forgot about those. How long after we left did the cops show up?