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Need advice: Flat tappet or roller in my hemi?
#1343580
11/30/12 06:17 PM
11/30/12 06:17 PM
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Joined: Jan 2004
Posts: 2,103
East Coast, NJ
fig426
OP
top fuel
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OP
top fuel
Joined: Jan 2004
Posts: 2,103
East Coast, NJ
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I've been researching, researching, and researching. It seems that with the solid flat tappet, I was always concerned about losing a lobe due to the current oils, even though I put in plenty of additives. So since I have my engine apart, I've been thinking solid roller. But from what I read about that, is, I'll be trading my concern for losing a lobe with a concern for losing a roller. So where do I go with this? I had no problems with my solid flat tappets with about 50 runs on it, although it was only .630 lift, shifting at 6300, through the traps at around 6800, if my tach is accurate. 10.96 @ 124mph.
It's the 528" hemi that I dropped the valve in over the summer. I've gone up to 11.3:1 compression, will be going aluminum heads. 3800 stall footbrake 727. 430 gears. 29.5 tire. 4000lbs. 2 750's on an open plenum intake. 2 1/8 supercomps through 3.5" aero chambers.
Chris from New Jersey
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: fig426]
#1343582
11/30/12 06:27 PM
11/30/12 06:27 PM
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Joined: Oct 2012
Posts: 1,106
Northeast
VincentVega
super stock
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super stock
Joined: Oct 2012
Posts: 1,106
Northeast
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There's no question. A roller cam, even all other things being equal, will have less rotating friction.
If the camshaft profile is correct, you can get a bit more power and drivability out of the same lift and duration because of the increased ramp. And, like you say, it removes the oil additives problem, and also removes the need for breaking in a cam which is always a dice roll.
Looking for 1975 through 1978 B body 4 door sedan sheet metal or parts cars - monaco, fury, coronet. Please let me know
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: 66er]
#1343587
11/30/12 07:44 PM
11/30/12 07:44 PM
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Joined: Feb 2005
Posts: 4,313
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,313
Prospect, PA
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Quote:
If you can afford to do it with good quality part ie: Isky tool room or manly next tech spings, Isky Red Zone or Crower Sever duty lifters, then the solid roller is the way to go. They make great parts that will last a long time.
.....and don't go crazy with the lobe profile.
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: fig426]
#1343588
11/30/12 09:01 PM
11/30/12 09:01 PM
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Joined: Oct 2007
Posts: 4,206
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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Adjust the lash frequently. If one valve starts to move, pull and inspect that roller.
As little idle as possible.
Don't second-guess the mfg. on spring loads.
Boffin Emeritus
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: jamesc]
#1343592
11/30/12 10:08 PM
11/30/12 10:08 PM
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Joined: Dec 2005
Posts: 4,231
State of retirement
52savoy
master
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master
Joined: Dec 2005
Posts: 4,231
State of retirement
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Quote:
there are improvements you can make to flat tappet systems these days such as nitriding, face fed oiling on lifters and tool steel lifters. i know roller systems are superior but solid cams have made a lot of power over the years. i've never had any problems (having said that i now will) and for sure having a failure is a real mess but i believe if sound practices are used a solid can live a long happy life
X1.. You can groove the (lower part)lifter bores with a tool from I believe CompCams. It allows a small amount of oil to leak by and spray on the cam lobes. 
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: fig426]
#1343596
12/01/12 12:10 AM
12/01/12 12:10 AM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
One other thing. I'm not chasing ET's here. I'm happy being an 11.0 car. Although hitting 10.96 for the 1st time was pretty cool. 
w/ 528 ci of Hemi, I'd be mad if it didn't run 10's.
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: Mr.Yuck]
#1343597
12/01/12 12:24 AM
12/01/12 12:24 AM
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Joined: May 2004
Posts: 12,386
Taxes & Virus's R-US, NY
Dragula
I Live Here
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I Live Here
Joined: May 2004
Posts: 12,386
Taxes & Virus's R-US, NY
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I have done both with my Hemi, and its a matter of preferance. With proper break in and spring pressures & oil, a flat cam should last a long time. I am currently running a .608 lift solid mechanical and I have already had my little 484 pump gas hemi in the 10.90's.
Now I also ran roller cams for many years in my Hemi, and if you keep the lift mild, and use a good manufacturer, all will last a long time as well. As soon as you go looking for all that untapped hp with a roller, you find all the weak links in the valve train. Ask me how how I know. I went thru a lot of parts running a .750 lift roller on the street.
Its all preference..
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: Mr.Yuck]
#1343598
12/01/12 04:51 AM
12/01/12 04:51 AM
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Joined: Jan 2004
Posts: 2,103
East Coast, NJ
fig426
OP
top fuel
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OP
top fuel
Joined: Jan 2004
Posts: 2,103
East Coast, NJ
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Good info from all you guys that actually run, or ran, each of them. On the roller side, are the $500 rollers sufficient, or do I need to be stepping up to the $1000 ones?
Chris from New Jersey
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Re: Need advice: Flat tappet or roller in my hemi?
[Re: fig426]
#1343599
12/01/12 06:20 AM
12/01/12 06:20 AM
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Joined: Jan 2011
Posts: 4,785
Utah and Alaska
astjp2
master
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master
Joined: Jan 2011
Posts: 4,785
Utah and Alaska
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I went with Crane 66550-16 lifters with pushrod oiling and a crane cam that is 242@.050 and .608 lift with a 112 LSA, it idles great and with my 9.5 to 1 pistons its a great street/strip combo. Contact Chase Knight at crane for a recommendation. Tim
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