parts interchange

I know its a dumb question but its just to prove a point. Are there any parts from a Ford 302, that will fit a small block Chevy? (crank, rods, pistons)  

the air cleaner ass.. if both run a holly  

Radiator cap,, courtesty of the wife.....    ; )  

HOW DARE YOU! EVEN THINKING OF PUTTING FORD PARTS IN A CHEVY

but even though it's off topic, those 514 Ford guys sure like to use BBC stuff

Actually you're kind of going the wrong way. It used to be common in the pre roller cam days to build up a SFC with SBC parts. Mostly but not limited to rockers, valves, springs and retainers.

Ford and Chevy pistons can be interchanged and are by "pros" who are adjusting total piston height in the block to allow changes in rod length to either engine.

Bogie

I just read somewhere in CHP about ifter bores in chevy engines beeing honed to accept Mopar lifters because the larger size is more durable. I think it was talking about rooler lifters.  

I allmost sold a set of 993 heads to some guy once.The problem was he swore he was gooing to put them on his pontiac 301. I couldent do it, I later sold them to someone who understood what he was getting later.  

The SBC and BBC use a flat lifter that is a bit smaller in diameter than those of Ford or Chrysler. There are mushroom shaped lifters available for Chevy engines, but the seemingly quick and cheap solution was to bore the chevy lifter bosses to accept the larger FoMoCo or MoPar lifters.

Within reason the larger diameter flat tappet reduces the loading between the lifter and the lobe; and extends max lift open time for the valve by virtue that the lobe tip must traverse a longer distance from one side of the tappet face to the other.

For a roller there is less to no effect since there is adaquate space in the Chevy lifter for sufficient roller diameter to minimize loading between the roller and lobe. Also, a roller doesn't have the effect of the one end of the face to the other wiping effect of a flat tappet. The roller makes instantainous contact rather than wiping contact, hence the big difference in lobe design. The flat tappet lobe is peaked, the roller lobe is quite broard across the top in comparison in order to get the open time comparable to that of a flat tappet. And yes all those magazine pictures that show a flat tappet and roller tappet cam together and tell you how that board lobe of the roller compared to the flat tappet results in more valve action and timing, simply ain't so.

Bogie  

And yes all those magazine pictures that show a flat tappet and roller tappet cam together and tell you how that board lobe of the roller compared to the flat tappet results in more valve action and timing, simply ain't so.

Bogie  

Come on, The valve can be off the seat for the same lenght of time but it can't reach max lift and stay there for the same amount of time. Other wise no one would be talking about useing fomoco or dodge lifters for their larger diameter and potential cam profiles thet go with them.

ACAJOE

A 400 SBC fitted with Ford 6 rods makes a perfect 350 according to Hot Rod.  The did an article on that a couple years ago..

Bob

OK let me go through this once more. To start with I'm picking on an example not the specific. There is no doubt that you can get more acceleration rate and more gross lift and duration from a roller cam compared to a flat tappet. But this is mostly the zone of race only engines.

The picture that so many magazines and books show of a narrow peak on the lobe of a flat tappet cam compared to the broad lobe of a roller tappet cam is not explaning to you how these cams function in regard to passing the lobe under the lifter. If you have a flat tappet cam and a roller tappet cam of exactly the same timing and lift when measured at the lifter or valve; the roller when all you do is  to look at it will appear to have a much longer duration because of the very broad lobe. If you were to put each cam with its lifter in a block and using a degree wheel and dial indicator both of these cams would measure the same duation and lift at the lifter. So what's going on, why do two radically different looking cams measure out the same.

The reason why these two identially timed and lifted lobes look different is that a different situation exists between the lobe and the lifter. In the case of the flat tappet, upon reaching maximum lift, the lobe sweeps across the face of the tappet from one side to the other. The time it takes for the lobe to sweep across the flat has a lot of degrees of cam and crank rotation occuring. The roller cam on the other hand does not have the sweeping motion from one side of the lifter face to the other (because it doesn't have a face), It makes instantaneous contact, therefore, the duration must be built into the lobe. This, all other things being equal, makes for a wide lobe at maximum lift.

So simply laying a flat tappet cam and a roller lifter cam side by side and saying the roller cam provides greater lift and duration because it has a broader lobe is not necessarily factual when you consider the different way these cams interface with their respective lifters.

Now if you have a flat tappet cam using chevy lifters you get a certain duration, think of it as what that cam is advertised to provide and you're checking this out with a degree wheel and dial indicator to verify that you've got what you bought. Now lets say if you modify the block to accept a mushroom faced tappet or the larger diameter Ford or Chrysler flat tappet but keep your original cam. If you now check duration and lift at the tappet with your degree wheel and dial indicator, you will find that there's a few more degrees duration all at max lift. Whoa dude, what happened, is my cam growing or what? What happened is that it takes more time ,or degrees of rotation, for the trusty old lobe to sweep under the now greater distance across the face of the larger diameter tappet. If this were a roller cam and you decided to put a Ford or Chrysler roller tappets into the engine, which would require you bore the lifter bores larger to get them into the engine. Upon checking the original roller cam's duration and lift with a degreee wheel and dial indicator, you would find the duration and lift were the same as originally advertised because the contact between the lifter and the cam is always instantaneous never sweeping.

So all other things being equal cam lobes are shaped specific to the type of lifter. A flat tappet lobe sweeps across the face of the lifter, the time and, therefore, duration it takes to do this is determined by the diameter of the lifter, (as well as the shape of the lobe), but a bigger diameter lifter requires the lobe take more time to cross it. The roller on the other hand, makes a little line of contact taking essentially no time or duration to pass over the lobe, therefore all the duration has to be built into the shape of the lobe. That's why they will always look different even if the timing and lift at the lifter or valve is the same. Jiggling lift and duration goes on top of this difference, and yes a wild roller lobe is a beast to behold.

Bogie

Well said.  One only needs to look at a flat tappet cam and a roller cam to visualize what you're saying... the flat tappet cam's lobes are "pointed" and the roller cam's lobes are more "rounded."   

Old,Bogie explained this best. I think where some people get mixed up is looking a lift and duration @ .050 on one cam and not the other.Does a roller cam help you get away with lobe spacing? It seems that a roller cam can have more lift and duration and stll maintain low end torque,vacumme and driveability.unless I have ben looking at advertised instead of >o50 duration.  

OK let me go through this once more. 

(yes dad )

" There is no doubt that you can get more acceleration rate and more gross lift and duration from a roller cam compared to a flat tappet.

Bogie"

Hey, I    get what you're saying. And you think roller cams are too expensive for the average streeter. For the ten years I've owned my truck it has seen 5 different cam/head/exhaust/displacement configurations. I've tried flat tappet and roller cams back to back. I know the roller is better, I drive the results every day.

If you think you can make a flat tappet cam that is just as good without the price tag, Then Apply For Job at COMP CAMS.  They are always looking for your kind of talent.

When someone asks for various opinions and I give mine don't blather about how I must not understand. I get it. But just like in the magazine when you, I or anyone else tries to boil such a complex subject down to a simple answer there is always someone unhappy.

ACAJOE 'roller cams for ever' 

It seems that a roller cam can have more lift and duration and stll maintain low end torque,vacumme and driveability.

( from gearman)

It can have more lift for the SAME duration.

ACAJOE