I know this is probably a stupid question but why does some SBC's have an oil filler tube in the front of the motor and some dont??

Way they were designed. 67 and 68 Camaro had oil fill tubes up front. 69's had them in the valve cover.

But some of the intakes i see have the oil filler tube in the front. Does it matter? I suppose they are interchangable??

Prior to the PCV system SBC motors vented the crankcase threw an Outlet tube usually found on the back of the intake manifold next to the distributer so it was practice to put an Oil Filler tube on the Front of the intake as there was room for it at this location. Newer engines got a PCV system to vent the crankcase and as more accessories were bolted onto the front of the engine they took up space were the filler tube was - so the Oil Filler Tube on the front of the intake had to go and is now usually found on a valve cover.

Depends on what you're trying to use the intake for. Are you restoring a car to originality? Each manifold is specific to an application. The 67 and 68 Z28's have the thermostat housing in the middle and the 69 has it off center. They also have different casting #'s. I can't speak to every model, but most have certain casting numbers for each engine combo.

Depends on what you're trying to use the intake for. Are you restoring a car to originality? Each manifold is specific to an application. The 67 and 68 Z28's have the thermostat housing in the middle and the 69 has it off center. They also have different casting #'s. I can't speak to every model, but most have certain casting numbers for each engine combo.


Ditto on the above Tom and never a stupid question thats how we learn ...Hi Harvard: hope the new year been good to you ,very good here lots of new parts going together to make a good setup I hope,see ordered wednsday in the performance forum if interested ,hope we can all get together this summer,sorry Tom didn't mean to hijack....:) Happy Motoring

Ditto on the above Tom and never a stupid question thats how we learn ...:) Happy Motoring
:thumbsup:

:thumbsup:


Hope to see you too this summer Fred :),I am not good at planning ,but maybe a collective effort ,for the Puget Sound area T/C gang...Happy Motoring

Prior to the PCV system SBC motors vented the crankcase threw an Outlet tube usually found on the back of the intake manifold next to the distributer ...

Just to clarify;

Prior to the PCV systems - there was a "Draft-tube" system that allowed vapors to flow from the fill tube vented cap inlet, through the block and be drawn out of the draft-tube by the negative pressure differencial at the tube outlet. The vapors and crankcase bi-products were dumped into the air flow under the vehicle.
These draft-tube systems were never installed on Camaro engines from the factory.

The 'outlet' for the crankcase vent was cast into the rear of Pre-1968 blocks (for automotive use - marine, industrial and truck continued for several more years) - not the intake manifold. :noway:
Inlet vent air to the crankcase entered via the cap on the oil fill tube on "Open" PCV systems and through the rear vent on "Closed" PCV systems (a reversed flow to the 'open' venting design).
The PCV valve was mounted in the rubber tubing leading from this rear vent hole to the intake on 1967 "Open" systems.
The PCV valve is screwed into the fill tube and routed to the intake via rubber hose on the 1967 "Closed" systems.

There was also an oil-seperator installed internally in the block lifter galley (below the manifold) that caught most of the oil out of the vapors exiting the vent hole.

1968, and later, automotive blocks do not have the rear venting provision hole and used the valve cover holes to allow crankcase vapors to be vented to the intake to be burned off during operation.
The passenger (right) side is the inlet side to the crankcase vent air flow of the post-68 PCV systems and the PCV valve is mounted in the Drivers (left) side valve cover (or in the tubing run of a few set-ups) as the vapor outlet to the intake system for the vapors to be burned.

John:

Great info re PCV history. Come to think of it I do recall seeing that Oil Baffle Canister in the lifter gallery on older blocks but man - that was some time ago - LOL

You ever get behind an old car in traffic and see steam coming out from under it?? And it stunk of unburned crap!!

That's the engine ring blow-by that is expelled out the road draft tube!! EPA said it caused right a 35 percent or so of ALL vehicle smog forming air pollution emissions so it was done away first out in Cali like about '63/'64!

pdq67

I've got a 50 Buick with the tube out the back of the block. Smells like nostalgia.

I guess they didn't attempt to dump the draft tube into the OIL Bath Breather for fear of flooding it with oil or causing a Crank Case explosion.

... but man - that was some time ago - LOL

Yeah, I'm old - go ahead and rub it in :yes:
ps: tomorrows lesson will be the art of 'scraping babbit' - be sure to tune in :D

John: I learned to drive in a 55 Ford in 66 - so take it from there. Don't tell anyone but it was faster the a 56 Pontiac and left a 56 Olds 98 behind - LOL

Ron, I got ya beat. I learned in 64, in a '54 Hudson Hornet 2dr HT, with dual H Power, factory traction bars, and HydraMatic 4 speed. It would start the engine by coasting up to 5mph and dropping into low. We had to do that a lot. The battery was 6 volts. Drove it all through high school.

John: I learned to drive in a 55 Ford ...
Ron, I got ya beat. I learned in 64, in a '54 Hudson Hornet 2dr HT ...

So you guys learned on cars with Electric Starters :o

I still got a scare where I put my teeth through my bottom lip when I walked into the bumper of a 36 Hudson. I wasn't very tall then and the car was over 20 years old. That car had a Starter with a BIG Button on the floor (no solenoid I imagine) and yes it did have a Crank under the Grill. I can still see my Dad cursing as he swung it trying to get that straight 8 started.

In it's day a Hudson Hornet was one heck of a ROAD CAR!

As were my Dad's several new big Packards he drove back then in '49 and up to '55 or '56!

He'd take the one we had at the time and get it tuned up Sat. morning and then take a drive out in the county that afternoon and set it on 110 mph for miles and miles back before there were any speed limit's in IL!!

Talk about flat going down the road!

I was just a wee pup back then!

pdq67

My Dad had a 51 Buick Special stright 8 ,3 on the tree and in the Safeway parking lot he would put me in his lap and let me steer ,she would float down the road on trips he had her til 1965 whan he bought a 1965 Buick Wildcat 425ci 340 hp,he was going to get the daul Quad's360 HP setup, but Mom said no ,she didn't want to spend the extra I think it was 75 .00 ,thay still have it or I should say I have it they gave it to me a couple yrs ago ,I only take it out about 5 times a yr. to keep things going I want to redo the breaks as it a single res. M/C I don't like that .sorry got carried away ,but memories are cool..HAPPY MOTORING . Sorry TOM I hyjacked you again