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1.5 vs 1.65 rocker arms

  
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1.5 vs 1.65 rocker arms

 
1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/27/13
07:38 AM

I am currently running 1.65 ratio rocker arms, and I am considering going to 1.5 ratio.  My cam is a Crower 60244 240/242 and 501 lift.  What would the difference be in running a 1.5 ratio instead of 1.65?  

Pontiacman8 Pontiacman8
Moderator | Posts: 5775 | Joined: 02/08
Posted: 07/27/13
08:15 AM

Is that .501 lift with the 1.5 or the 1.65 rockers?  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/27/13
09:26 AM

Sorry, that is 501 with 1.5.  I also have ported Kauffman heads and a port matched Performer intake and a Pro Systems carb.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/27/13
02:25 PM

As far as rocker brand goes, what are you currently running? In the mid price range I suggest full rollers from Scorpions or possibly Harland Sharp. Many of the others are Chinese made and many failures under average to moderate conditions have been seen.  

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/27/13
03:09 PM

I am running Scorpions and I intend to buy Scorpion in 1.5 if I switch.  In the past on other engines I have run Harland Sharp with good luck but I see that they are more money now and have had good luck with Scorpions.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/27/13
03:56 PM

have had good luck with Scorpions."  

Typically not much luck involved when one buys US made parts over imports [unless one has a Toyota, lol].

Scooorpions.  

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/28/13
07:05 PM

Will 1.5 ratio put less stress on the lifters then 1.65.  It seems to me it would open the valves with 10% less effort and open the valves 10% less.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/28/13
07:50 PM

Yes, close, but no one has ever asked that before which begs the question, why do you ask? Do you have a problem?

Please don't tell me you have lifters ticking and your lifters are Comp Cam's. If so adjust them to 1/2-5/8 turn in from 0.  

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/28/13
08:23 PM

Yes my lifters are ticking, I am going to replace them tomorrow.  My parts store suggested Comp Cams lifters again, but I am going to use Crane lifters.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/28/13
08:49 PM

Ahhhhhhhha, Another comp lifter tick victim, lol!

Sorry, but if you adjust them as I say the tick normally goes away unless there is other damage to them.

Cranes should be high rev type. I love Crane's.

I set them 5/8 - 3/4. If they tick your cam is going flat.

I would break them in just like a new cam. Including using ZDDP oil.

Isn't your cam new?

Don't be afraid to run the 1.65 rockers.



Perhaps you could be persuaded to use my favorite rockers below. They have "a colorful charming appearance" and resist "weariness" [becoming tired, lol].


Sunglory aluminum rocker arms feature colorful charming appearance owing to the anodized treatment to resist weariness.

Machined from the high quality extruded aluminum alloy, using state-of-the-art extrusion processing to ensure the superior flow of the aluminum grain for optimum wear resistance, our rockers are provided in 1.5, 1.6 and 1.7 ratios.

The needle bearing machined (instead of stamped)offer the advantage of high strengthand smooth operation. Roller tips are heat-treated too for superior durability. Polylocks are provided.

Sunglory aluminum rocker arms are the best choice for racers at an affordable cost.


http://www.sungloryparts.com/showproduct.asp?id=121  

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/29/13
05:14 AM

70bird thanks for the info.  Yes it is a new cam, Crower 60244.  I should get my lifter today and I will break it in like a new cam.  

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/29/13
12:31 PM

I got the old lifters out and they look good and so does the cam.  Now tomorrow I will have the rest of my parts and I will get the engine together.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/29/13
12:58 PM

"I got the old lifters out and they look good and so does the cam.  Now tomorrow I will have the rest of my parts and I will get the engine together."


Good news, return them to comp for diagnosis or shop you bought them from and get credit or refund.  

ROWSLEY ROWSLEY
Guru | Posts: 1016 | Joined: 07/11
Posted: 07/30/13
08:25 AM

70 what about comp hyd rollers. heard of any problems with them?

461 did you check for push rod to head clearence? if the push rods are rubbing on the heads you will not be able to ajust the tick out!!!!! a common problem when using 1.65 rockers.

any company that sells 1.65 rockers for pontiac should tell you to check push rod clearence at the top of the hole by the stud!!! no matter what type of head you have.  
76 455/4spd TRANS AM
69 GRAND PRIX 455/5SPD

1979TA461 1979TA461
User | Posts: 63 | Joined: 06/13
Posted: 07/30/13
11:40 AM

I did check the clearance of the pushrods and they were OK.  I have Kauffman heads, they have plenty of clearance for 1.65 pushrods.  

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