Thread: Motor Rebuilding Issues

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Today I started to unhook My motor for rebuilding. I am rebuildding a 327, 1968. I would like to hear some dos and don,ts about rebuilding a small block. And thier are some issues that I have. Issue 1. Are small block heads the same as far as how they fit on the motor? Issue 2. Is it better to use headders rather than stock exhast manofoils for the street? Is it better to use HEI rather than a point system for Street. How important is a PVC? What,s a good way to brake in a motor? Is there a way to tell what kind of car a intake manofoil comes off of? A lot of questuions, I know,LOL. But I,ll have a few more I,m sure. Thanks, John.

Originally posted by Johnwalkeasy
Today I started to unhook My motor for rebuilding. I am rebuildding a 327, 1968. I would like to hear some dos and don,ts about rebuilding a small block. And thier are some issues that I have. Issue 1. Are small block heads the same as far as how they fit on the motor? Issue 2. Is it better to use headders rather than stock exhast manofoils for the street? Is it better to use HEI rather than a point system for Street. How important is a PVC? What,s a good way to brake in a motor? Is there a way to tell what kind of car a intake manofoil comes off of? A lot of questuions, I know,LOL. But I,ll have a few more I,m sure. Thanks, John.

1. yes 99% of the time this is true...
2. yes.. any exhaust tech will tell you that stock exhaust manifolds dont flow half as well as headers, you'll get better performance with headers.
3 yes HEI is much better than points for any application, points have to be adjusted and changed every so often, the HEI will put out a cleaner spark and have less maintance.
4. PVC, yes it is important, i've seen motors hardly run at all because they dont have a PVC, i've also seen oil pressure issues because of not having one.
5. best way to break in a motor is first run it for 20 minutes at about 1500-1800 rpms for the intial break in, use standard oil not synthetic and keep it stationary without a load, the engine will tend to run a little hot one break in so make sure your cooling system is up to snuff, dont use an old radiator thats all plugged up, at least get it rodded out. change the oil, if you plan on using synthetic you can now start using it. now drive the motor how you plan on driving it all the time, just dont be slamming it and putting huge shocks on it. change the oil after 500 miles.. good to go.
6. cant tell what car an intake manifold came off of, but you can find out what motor it came off of with the casting numbers.

thanks Sal for your good answer. Would you know if all stock exhast manofoils are the same. Or are they bigger for a 350 than for a 283? Thanks, John. BTW, You may have address this issue before. But would the 327 in a 1968 truck, have for sure 6 volts going to the points? And if I can find no condensir or any kind of piece between the coil and the starter. Would that mean that it is a 12 volt? Thanks, John.

i think the manifold size really matters more on vehicle/application and the year it was off of... i'm not much of a chevy guy so i cant give you too many details on that.... and the voltage should be checked with a voltmeter when the ignition is turned on.... if it comes up 12 then you're good... if theres no visual ballist resistor and you're coming out 6, then its the wire itself.... and you'll have to replace your coil wire with just some standard automotive wire.... if you dont have a voltmeter/multimeter, its a good $30 investment, you'll be amazed how many times you can use it when you're having electrical issues to solve things a lot quicker

On the headers, if you don't want all the hassle and underhood head associated with headers, you might want to consider the ceramic coated "shorties" or block hugger headers. Not as good as equal length long headers, but better then the stock cast iron exhaust manifolds.....

AND USE THE EXHAUST MANIFOLDS FOR BREAKIN IN THE CAM ,DONT USE CERAMIC HEADERS IT'LL RUIN THE SHINE ,I FOUND OUT THE HARD WAY

good tip, 75mbsl.... i wouldn't know cause i've never had headers at time of breakin

Originally posted by thesals
1. yes 99% of the time this is true...
2. yes.. any exhaust tech will tell you that stock exhaust manifolds dont flow half as well as headers, you'll get better performance with headers.
3 yes HEI is much better than points for any application, points have to be adjusted and changed every so often, the HEI will put out a cleaner spark and have less maintance.
4. PVC, yes it is important, i've seen motors hardly run at all because they dont have a PVC, i've also seen oil pressure issues because of not having one.
5. best way to break in a motor is first run it for 20 minutes at about 1500-1800 rpms for the intial break in, use standard oil not synthetic and keep it stationary without a load, the engine will tend to run a little hot one break in so make sure your cooling system is up to snuff, dont use an old radiator thats all plugged up, at least get it rodded out. change the oil, if you plan on using synthetic you can now start using it. now drive the motor how you plan on driving it all the time, just dont be slamming it and putting huge shocks on it. change the oil after 500 miles.. good to go.
6. cant tell what car an intake manifold came off of, but you can find out what motor it came off of with the casting numbers.

I agree with a majority of this but I would run the r.p.m.'s a little above 2,000 and vary the r.p.m.'s up and down a little to change the (oil splash).I would not add any synthetic oil until you have over 3,000 miles on the engine or your rings will never (seat).Maybe even more if you have moly rings in it.

Thanks again for all the input. I noticed today there is an electric wire going to the auto transmission where the speed ometer cable is usely at. So I guess the trans has a electric speed ometer. Ive, also got some wireing that go,s to carburarator that,s not conneckted up. John.

wiring for the carb is for an electric choke most likely.... and the synthetic oil depends.... GM adds it after their 36 hour burn in on corvette motors, but they also use much less leanient restrictions when it comes to bore and rings......the moly rings technically never seat, because theres supposed to be no break in required on them.... this is coming from fresh college info..... but once again, i've never used them in my engine builds

Two more questions. Would stp be a good oil to coat crank and barrings with.or should I use somthing else? Also, If cam is stock, what sould they mic at? Thanks, John.

STP works... but i reccomend actually using bearing grease... lots and lots of it... you can never use too much of the stuff

I don't know if I'd use a whole lot of heavy grease, I've read where some guys have had a problem with it plugging up the oil pump screen. It just doesn't seem to want to break down and mix like you'd think it would. I would clean the cam within an inch of its life and then massage it with the black molybdenum disulfide that comes with the cam. Here's a cam break-in procedure that I follow.
CAM BREAK-IN
Anyway, use only stock springs to break in the cam, changing them to the springs you're going to run after you have several hundred miles of easy runnin' on the motor. Fill the crankcase with racing type oil that has sufficient zinc content to protect the cam. (Read the article in Car Craft March 2006 concerning the removal of zinc by the oil companies). Add one bottle of GM Engine Oil Supplement, available at any GM dealer. Prime the oil galleys. Adjust the valvetrain and spark advance so that the engine will crank right over. Bolt on a carb that is primed with gas and ready to run. DO NOT, REPEAT, DO NOT GRIND THE STARTER TO START THE MOTOR. IF IT DOES NOT START RIGHT AWAY......STOP!!!!!...... FIND OUT WHAT IS WRONG. While an associate monitors oil pressure and water temperature, bring the r's up to between 2,500 and 3,000 and hold it there for 20 minutes. Shut down, replace oil, filter and GM EOS. Run easy for 300 miles. Replace oil, filter and springs. Enjoy.

the bearing grease's for building motors are supposed to disolve once they start getting oil and heat mixed with them... thats at least what they're supposed to do

Gotta agree with Tech, use cam lube to break in the cam. I use whatever motor oil I'm going to be using later to coat everything else on assembly,and prime the system before firing. If it's going to sit a while before being fired, I use white assembly lube. It is designed to disburse when replaced with oil flow. I use his procedure also to break in for 30 to 45 min. and then replace oil and filter. Hank