WILL PISTONS HAVE TO BE NOTCHED?

[danny clemens]

On an Eagle 408 stroker engine with Keith Black pistons (KB319 with 27.5cc dish) will the pistons have to be cut for clearance when using 60259 Edlebrock Heads? The heads have 2.020 intake and 1.600 exhaust valves. I'll be using a cam with probably no more than a .500" lift. Will it work, not work or be close with this setup without notching? Another question I have is will the bottom of the cylinders have to be notched to clear the rods. Eagle "SIR" connecting rods come with the kit.

 

[mustangdave]

Only way to be sure is to mock it up:clay the pistons w/the heads on and turn it over by hand, the measure the clearance. With oil pan off turn over and watch rods to see how much clearance. Any engine should be mocked up at least once, if not more to check everything.

 

[dennis112]

Only way to be sure is to mock it up:clay the pistons w/the heads on and turn it over by hand, the measure the clearance. With oil pan off turn over and watch rods to see how much clearance. Any engine should be mocked up at least once, if not more to check everything.

Agree with Dave. You must assemble the motor "at least" twice in order to verify and correct all clearances. Some motors combinations need clearanced, some don't--the only way to find out is to mock it up first.

 

[danny clemens]

I was just hoping that because this is probably an often used combination (especially the Eagle crank and rods) for a 408 stroker that somebody that had been through it before would share some info.

 

[Max Power]

Ebery one turns out different Danny. Some engine will require cylinder notching, some not. My counterweights didn't require major notching, but they did hit the piston land right under the pin, which is very unusual. I had to pay for custom work to the crank to get it all to work.

As for the valve to piston question, someone here may have run a similar combo, but you still want to check with clay, especially since you diidn't provide much cam info. Valve timing is a factor in addition to lift.

 

[danny clemens]

Thanks for the info guys. Looks like I need to find some info on using the clay.

 

[mustangdave]

To explain further, every part in the engine has a tolerance it can be over or under. These sometimes add up and create a problem with one engine and not another even though it has the same build.

 

[danny clemens]

I just called a guy up at Keith Black technical help about the KB319 piston and he said that the 2.020 valves would work with just about any cam I wanted to put in there. I mentioned cam numbers of .500 lift, 110 degrees of lobe seperation and 224 degrees duration @ .050 lift (not necessarily the cam I'll be using but close) and he said that it would be OK. I think I'll still check the piston to valve clearance just to be on the safe side.

I'll put the crank, rods and pistons in to check all of the clearances before I get everything balanced just in case I have an issue.

 

[Shakin66]

I would be VERY careful listening to anyone as to wether they think it will clear or not. I called ford racing and they said..."You'll be fine..." well it wasnt so I checked it with clay and the method that uses the weaker inner spring and liked it much better. If you need some info on that let me know but if you google "piston to valve" you will find it.