Reinstalling Hillside Stage IV Heads....
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,703
Likes: 7,887
From: poway
Not sure on the year of the heads but we're stage II.. I bought them off of a forum member who I just had them redone by Hillside.. They were not the newer style heads with automatic compression releases.. So I imagine they were early style.
The current heads that I had set up for stage 4 are of a later style that actually came off of my 2013 motor..
I have no idea what the CFM was on the stage II heads.. Obviously there's no comparison in the amount of air flow between the two different heads because of the difference in the tune that is necessary to make the motor perform properly.. I am by no means a great guru But I do know that these motors are just a pump and the more air you can flow through the pump the greater your power numbers will be..
The older tune that I have in there now is working very well and my engine temps never went over 260, so I'm happy with that..
The current heads that I had set up for stage 4 are of a later style that actually came off of my 2013 motor..
I have no idea what the CFM was on the stage II heads.. Obviously there's no comparison in the amount of air flow between the two different heads because of the difference in the tune that is necessary to make the motor perform properly.. I am by no means a great guru But I do know that these motors are just a pump and the more air you can flow through the pump the greater your power numbers will be..
The older tune that I have in there now is working very well and my engine temps never went over 260, so I'm happy with that..
Thread Starter
|
Seasoned HDF Member
Joined: Mar 2010
Posts: 20,850
Likes: 7,391
From: Poolville
No on the valves.. I specified from the KPMI catalog exactly which valves I need to get the tip protrusion down to where it was manageable.. 2.020" intake and 1.615" exhaust.as indicated in the attached pic. 5/16" stems.. I believe they were shorter in overall length by .090"intake and .075" exhaust. Plus adding the .040" height increase to the rocker shaft when I had Vulcan custom make the rocker mount assembly's, it really helped to correct my rocker geometry not to mention the addition of the S&S roller rockers. So far all works very well and with the older tune in it, it perofrms verry nicely.
Thread Starter
|
Seasoned HDF Member
Joined: Mar 2010
Posts: 20,850
Likes: 7,391
From: Poolville
No, Stage II heads have 1.900"/1.575" with mild porting and the current Stage IV heads have the 2.020"/1.615" valves with extensive porting.
Thread Starter
|
Seasoned HDF Member
Joined: Mar 2010
Posts: 20,850
Likes: 7,391
From: Poolville
118 hp/122 tq.. A little disappointed.. I thought it would be more.. Maybe the pipe and Woods 888 cam are holding it back.. Did much better with the small primary Hooker 2-1 and the t-mann 662 cam...
Thread
Thread Starter
Forum
Replies
Last Post
98hotrodfatboy
Engine Mechanical Topics
10
Nov 12, 2024 02:00 PM