pushrod and eddy head trouble

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farmer260

73 Dart Sport
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I have a 360 with a solid cam and lifters, eddy heads and adjustable 1.6 PRW stainless roller rockers and 5/8 pushrods. now my trouble is the rods are hitting the heads. i put a stock set or adjustable 1.5 steal rockers with cupped 5/8 rods and they seem to be hitting too but not as bad. the stock rockers are not adjusted yet but the roller set was. what do you guys think?
 
First you have 3/8 push rods,not 5/8.You can get spacers to move the rockers over away from the intake ports just enough to clear the intake runners by .025.You need to recheck the location of the roller tip on the valve stem to be sure it contacts and opens the valve correctly.The 1.6 rockers bring the push rod closer to the intake runner causing the problem.Now how much rubbing is being done?Can the side of the head that the rods is touching be ground down a bit,or is it just touching casting flash?If so,a small amount of material can be remove to clearance the rods,by .010-.025.mrmopartech
 
its disassembly time if you want to use the 1.6s. elongate grind the holes to get clearance - its the only way, or go back to 1.5s. with 3/8 prds you may still have problems.

Just another "bolt on " performance part.
 
had the exact same prob with my eddies and 1.6's, i pulled the intakeput a big shop towell to cover the lifter galleyalong with plastic and more towells, then covered the heads up good except for the pushrod holes, found a drill bit a little bigger than half the hole size and put it on a drill, saw where the pushrods were hitting and went to town, i got my dad to hold a shop vac hose directly underneath the pushrod hole while i held the drill full throtle and moved it up and down to get the needed clearance. yes it is time consuming and is hard to do by yourself and hard to keep shaving out, take your time and wrap everything up good and it works fine. have had no more problems with mine and it works fine. also the crane and comp pushrods are different lengths, can't remember which is longer or shorter but one of the books aren't correct, whichever is suppose to be longer is actually shorter, i think don't hold me to that its been a while, i got some extra clearance like that to, i think i ended up using the crane pushrods, they had a little more clearance than the comp, but every motor is different, good luck:-D
 
Sorry about the typo on the rod size! ya i kinda thought it might come to this! oh well! the rods seem to be hitting on the side of the hole on some and on the top of the hole on others. i was thinking of getting a drill bit a little bigger than the stock eddy holes and just drill them out bigger. i will take the heads off to make sure nothing gets in the engine. i think just drilling them out bigger in stead of just grinding one side of the hole might be easier to do. i am going to check with edelbrock tech departmant frist just to make sure i have room to do this so i dont hit oil or coolant passage.
 
1.6 rockers tend to move the pushrod closer to the rocker shaft center line than a 1.5. Mine were no closer to the intake port, they were at the tip closer to the intake valve top.

Any reason you are using 3/8 pushrods? That's a pretty stout PR and may not be necessary unless you are running pretty serious spring pressures over the nose. IIRC, PR holes in Ede's are barely larger than 3/8" diameter. You'll likely be clearancing some big holes to clear the PR.

If you have a set of ported heads... be VERY careful around the wall adjacent to the intake port. The wall gets very thin. I didn't take any material out of the wall side to gain clearance.

I had to really clearance mine to get the PR though without hitting. Using 5/16 .083 hardened Manton pushrods. I used a air die grinder and a 3/8" double cut bit to cut material out and it became an oval for the most part. Here are a couple of pics of the finished product.

edeheadprhole.jpg

edeheadprhole1.jpg
 
the guy who is helping me build the engine said the 3/8 rods should be used. the eddy heads have stock springs. why can i just get a drill bit bigger than the holes there now and drill the holes out bigger rather than use a die grinder?
 
Farmer, he means that he used a die grinder instead of a drill with a bit to enlarge the PR hole. A regular drill, electric or Battery powered will do. Just keep that bit spinning fast.
 
A stock ede spring will put about 360# max on the rocker over the nose at coil bind, IIRC. A good 5/16 .083 walled pushrod will handle that no problem, even an .065 walled chrome moly rod would be up to the task. Going to a 3/8 rod will add unneeded weight to the valvetrain, weight is bad.

We've run fairly big rollers with more spring pressure than the ede springs using 5/16 pushrods with no issue.

Might I suggest a call to one of the custom pushrod manufacturers, (Manton, Smith, Trend) and ask them what they think is necessary. Bigger isn't necessarily better in the case of pushrods.

Just some food for thought.
 
well i have already bought the rods but i guess i could sell them and get new ones. all i would need is the rods to be the same length as the 3/8 ones i have and i would be ok. so 5/16 with .083 should do me then! and that means i wouldnt need to take as much off the heads to make them fit right? any idea what size drill bit i would need to make the hole big enough to clear the rods?
 
borrow or rent a die grinder with a 1/4-5/16" carbide bit and elongate the holes towards the rocker shafts , especially for the intake prds at the top 1/2 of the hole.
I also agree a 5/16" cmoly pushrod is more than adequate to use with the Eddy spring which tops out @ 320# @.580 lift.



farmer260 said:
well i have already bought the rods but i guess i could sell them and get new ones. all i would need is the rods to be the same length as the 3/8 ones i have and i would be ok. so 5/16 with .083 should do me then! and that means i wouldnt need to take as much off the heads to make them fit right? any idea what size drill bit i would need to make the hole big enough to clear the rods?
Click to expand...
 
If you use a die grinder, don't wing the thing at max RPM. turn it kind of slow. Aluminum has a habit of gumming up the bit.

If you can, get some kind of lubricant, dip the bit in the oil, and grind a little. You'll notice a change in the way the aluminum is removed. Re dip it and go again.

Dropping a drill bit through the hole will remove material where you don't want it gone. Namely the intake port wall side. The holes should look oval when done, not round.
 
i think i will put the rockers and rods on and turn the engine over by hand and mark next to the holes where the grinding needs to be done!
 
DO NOT TOUCH THE WALL OF THE PUSHROD HOLE THAT IS NEXT TO THE INTAKE PORT!

Please read what I wrote. It's says "not" to remove material there. Look at the pics I posted and you'll see that the oval is running the short length of the heads, essentially side to side. Not front to back as installed on the car.

Putting the rockers on and turning the engine over slowly will put a shiny mark in the pushrod hole where the rods are rubbing. Put checking springs on the valves. Makes it easier to get full range than fighting the actual valve spring tension. I had my heads on/off the engine probably 12 times getting the clearance required. It will take a while.
 
good job - mock up the assembly and run the rotation thru the 720* to make sure you have at least 20-30thou clearance during the complete valve lift cycle. you can get away with just 20-30lbs on the head studs.
 
Ive got the eddies with custom Manton 3/8 pr and 1.6 Dove rockers. No rubbing--no grinding .


We just went thru this with my buddies 440 . I told him which pushrods to buy and he got impatient and ordered some 3/8 that rubbed the head. I told him a few times he's ok with 5/16 ............
 
I run 5/16 0.80 Comp pushrods (7692) and 1.6 gold cranes with no clearance problems. I also am running around .560 lift an have not had any issues. Went 8000 rpm on accident and still no problems. My 2 cents
 
Yup.. dont need 3/8 PR, and as part of the check and correction, I always elongate the holes. You never shim laterally to get a PR to clear. You only shim to get the tip of the rocker centered on the valve. It's a good idea to do big and small blocks BTW. They are both a tight squeeze with anything but 5/16 PR and 1.5 rockers.
 
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