#1  
Old 02-21-2021, 08:36 AM
taff2's Avatar
taff2 taff2 is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: South Wales in UK.
Posts: 2,172
Default 3/8" pushrods with Edelbrock round port heads

Are any of you using 3/8" pushrods with the E heads, and did you have to grind out the pushrod holes in the heads for clearance?
Cam is a solid roller, .625" lift with 1.50 roller rockers
I'm not against using 3/8" tapered to 5/16" at the rocker end if anyone has used these? Thanks.

  #2  
Old 02-21-2021, 10:22 AM
73 TRANSAM 73 TRANSAM is offline
Chief Ponti-yacker
 
Join Date: Jun 2008
Posts: 545
Default

Taff
I'm actually using a 1/2" pushrods for my WP. I center the 1/2" drill to the pushrod hole and drilled it to a bigger 5/8" hole in my mill. I'm using a 1.6 TD rocker shafts. This is for my boosted 482.

  #3  
Old 02-21-2021, 10:58 AM
lakefect lakefect is offline
Senior Member
 
Join Date: Nov 2004
Location: kendall ny
Posts: 235
Default

Quote:
Originally Posted by 73 TRANSAM View Post
Taff
I'm actually using a 1/2" pushrods for my WP. I center the 1/2" drill to the pushrod hole and drilled it to a bigger 5/8" hole in my mill. I'm using a 1.6 TD rocker shafts. This is for my boosted 482.
wow, i got into the intake port using 7/16 p/rods

  #4  
Old 02-21-2021, 02:46 PM
73 TRANSAM 73 TRANSAM is offline
Chief Ponti-yacker
 
Join Date: Jun 2008
Posts: 545
Default

I do have a wide port eheads so maybe it don't apply here.

  #5  
Old 02-21-2021, 02:48 PM
73 TRANSAM 73 TRANSAM is offline
Chief Ponti-yacker
 
Join Date: Jun 2008
Posts: 545
Default

I do have a wide port eheads so maybe it don't apply here. I'm running boost with my junk.

  #6  
Old 02-21-2021, 03:09 PM
Apache Warrior's Avatar
Apache Warrior Apache Warrior is offline
Senior Chief
 
Join Date: Aug 2005
Posts: 292
Default

I’m using 3/8 pushrods with my standard port E-heads (72cc).

I did drill out the intake port pushrod access holes for 9/16 stainless thin-wall tubing, epoxied them into the ports (nice and secure) and used red Glypyal to coat the entire port so I can run e-85 and not have to worry about the ethanol degrading the epoxy.

The other pushrod holes were all drilled out to 9/16. No tubing.

No issues.

Using T&D shafts with Crower stand shims.

  #7  
Old 02-21-2021, 05:36 PM
charlie66's Avatar
charlie66 charlie66 is offline
Ultimate Warrior
 
Join Date: Dec 2004
Posts: 3,261
Default

Im using 3/8" in mine . Had .090" Milled off one side all the way through and .050" off the other side of the hole and then still had to file it the rest of the way with a 3/8' diameter round file to get .040" to clearance the rod to the head . It took some time but no issues with it hitting .. So the holes are of an oval shape . Theres no need to hog it out ..

__________________
My Half AN Injun.....
  #8  
Old 02-21-2021, 08:40 PM
69Goat1's Avatar
69Goat1 69Goat1 is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: Tahlequah Oklahoma
Posts: 3,054
Default

I have 3/8 pushrods in my wideports...when drilling we got into the port slightly but we welded it up and finished it out...turned out perfect.

  #9  
Old 02-22-2021, 01:13 AM
krisr's Avatar
krisr krisr is offline
Ultimate Warrior
 
Join Date: Sep 2003
Location: Sydney, OZ
Posts: 1,433
Default

I'm running 3/8" in mine. Butler opened them up for 1.65 rockers but I ended up using Comp SBC adjustable guide plates as that was all I could get for a 3/8" pushrod over here and spent a fair amount of time setting each rocker up so the pushrod clears and still rides the valve stem properly. Works great on my motor.

__________________
'71 Holden HQ Monaro - 3850lbs race weight, 400c/i - 11.4 @ 120
'66 Pontiac GTO - 389, 4 speed street cruiser
  #10  
Old 02-22-2021, 04:19 AM
lust4speed's Avatar
lust4speed lust4speed is offline
Ultimate Warrior
 
Join Date: Jul 2002
Location: Yucaipa, SoCal
Posts: 8,684
Default

Have 3/8" pushrods and 1.65 rockers with my first gen Edelbrock round ports. Forgot who warned me to be somewhat careful and only take the necessary cut back towards the rocker stud because the wall was said to be somewhat thin to the coolant area. Had a machine shop oval shape the pushrod holes with the Bridgeport for that reason, but when I changed to a cam with .720/.723 lift I just went in and did the second clearance myself with the die grinder. Didn't have to widen the pushrod hole at all.

__________________
Mick Batson
1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon in progress.
  #11  
Old 02-22-2021, 08:21 AM
taff2's Avatar
taff2 taff2 is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: South Wales in UK.
Posts: 2,172
Default

Ok thanks, I'll clearance the holes in the normal way then (same as my iron heads), just mill/grind back the top half of the holes at an angle towards the rockers. I've smoothed off the port pushrod bulges and I don't want to break through into the ports by running a bigger drill bit through the holes.

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:25 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017