Your donations help keep this valuable resource free and growing. Thank you.
|
Roller rockers/stock valve covers |
Post Reply | Page 123> |
Author | |
PHAT69AMX
AMC Addicted Joined: Jul/07/2007 Location: West Virginia Status: Offline Points: 5904 |
Post Options
Thanks(0)
Posted: Sep/27/2018 at 1:20pm |
Harland Sharpe 1.6 fit under stock valve covers on mine, about .51x" valve lift.
|
|
rang-a-stang
AMC Nut Joined: Sep/25/2018 Location: Camarillo, CA Status: Offline Points: 272 |
Post Options
Thanks(0)
|
Awesome! Thanks, gentlemen!
|
|
Boris Badanov
AMC Addicted Joined: Dec/14/2013 Location: NH USA Status: Offline Points: 4209 |
Post Options
Thanks(0)
|
3/8 Cranes fit, 7/16 (if they still make them) do not.
|
|
Gremlin Dreams
|
|
WesternRed
AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Offline Points: 5787 |
Post Options
Thanks(0)
|
I'm up close to 600 lift, but with Edelbrock heads if that makes any difference.
|
|
I've finally given up drinking for good...........now I only drink for evil.
|
|
mixed up
AMC Addicted Joined: Jun/16/2015 Location: Monroe mich Status: Offline Points: 2156 |
Post Options
Thanks(0)
|
I had Harlem sharp in my 290 with a 540 lift cam and edelbrock aluminum valve covers no problem but an more than that there might be issues
|
|
69 amx 290 auto
65 220 290 4spd 80 ford fairmont |
|
WesternRed
AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Offline Points: 5787 |
Post Options
Thanks(0)
|
1.7 Harland Sharp works fine for me under the stock covers.
|
|
I've finally given up drinking for good...........now I only drink for evil.
|
|
rang-a-stang
AMC Nut Joined: Sep/25/2018 Location: Camarillo, CA Status: Offline Points: 272 |
Post Options
Thanks(0)
|
Hey guys, my first post here on theAMCForum.
Reviving an old dead thread for some similiar help. I am building a 401 for my Jeep. I am looking to add 1.7 roller rockers but want to keep my stock valve covers. I see several of you guys have posted that you have roller rockers under stock covers but are they 1.6 or 1.7? Anyone know if 1.7's will fit?
|
|
348AMX
AMC Addicted Joined: Jul/03/2007 Location: Massachusetts Status: Offline Points: 4165 |
Post Options
Thanks(0)
|
The rocker ratio also plays a larger roll in those advertised horsepower increases so common in aftermarket aluminum roller rocker marketing.
Most V8's came with a 1.5 or 1.6 ratio rockers stock, and swapping a 1.6 or 1.7 ratio rocker will net greater valve openning so there can be examples of engines that will get 20+ horsepower from higher ratio aluminum roller rockers over stock rockers. In engines that can benefit from the higher valve "lift" when the cam installed isnt optimized are where those advertised gains really come from. The reduction in parasitic frictional losses dont really add to horsepower increases in a noticeable way at all especially if a flat tappet cam is still used. The camshaft lobe to lifter face contact is the greatest friction load in flat tappet engines. You can gain 3 Horsepower from using different viscosity oil in some cases. So selecting full roller rockers soley for horsepower gains isnt practical. |
|
amx39068
Supporter of TheAMCForum Joined: Feb/21/2008 Location: Arizona Status: Offline Points: 11576 |
Post Options
Thanks(0)
|
The 3-5 HP is from reduction in friction movement. Some additional power however is gained from more precise valve tip to rocker relationship and valve movement but where it really shines is in combination with other modifications like better valve springs, a bigger cam and other modifications that work well together and produce significant additional power which will be otherwise somewhat diminished without the added benefits of the roller rocker.
Think of it like getting a bigger carb or a performance intake each without the other. There are diminished benefits for each alone but when you add them together the compounded benefit is multiplied beyond the sum of the individual parts.
For a mild build I use roller tip rockers on adjustable studs. They are less than half the cost with much of the same benefits as full rollers and work fine with all your other stock valve train components. |
|
Dan Curtis-Owner and CEO AZ AMC Restorations; Facebook: https://www.facebook.com/amcmusclecars/ & Curtis Real Estate Development
|
|
badamx
AMC Apprentice Joined: Apr/04/2011 Location: Middlebury, IN Status: Offline Points: 58 |
Post Options
Thanks(0)
|
I thought my buddy's claim of 20-30 hp jump was a little shall I say "optomistic"? I am sure with a more agressive cam and other valve train components combined the cumulative hp bump would be better.
The 390 has low miles and is set up the way it was the day it was born which I found very adequate over the last 5 years of driving her. Are rollers alone worth the expense and trouble? Or would it be suggested I warm things over a little to make the car more lively? Like I said my friend is a drag racer so it is his natural inclnation to seek more power. The car is one of 181 as it sets with the Go-Pack 390 4speed and red leather interior. I hate to corrupt it. I have a 63 Falcon that I am making into a drag car so I can exercise my modification demons with that. Any thoughts? |
|
Post Reply | Page 123> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |