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Re: Flat cam
[Re: Crizila]
#2403515
11/14/17 02:42 PM
11/14/17 02:42 PM
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Joined: Jan 2003
Posts: 1,807
Mopar Country, Mi
ccdave
The Ultimate
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The Ultimate
Joined: Jan 2003
Posts: 1,807
Mopar Country, Mi
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[/quote] No 2 ways that a roller will make more power (usually). Unfortunately, flat tappet cams get a bad rap when there is a flat tappet failure when it is often not the cam / lifters fault. If you are in to a mild to moderate street/strip build (OP), flat tappet stuff works great for a lot less $. Built many in the .600+ lift range with no problems. Maybe I'm just lucky.  [/quote] When a customer hands me a check to build an engine for them it's not worth the risk to hope that a flat tappet cam breaks in properly. If a flat tappet cam goes south it's on me regardless of why, who or what. Install a roller and hope and "should be ok" are eliminated....
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Re: Flat cam
[Re: CSK]
#2403570
11/14/17 04:40 PM
11/14/17 04:40 PM
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Joined: May 2003
Posts: 6,559
Downtown Roebuck Ont
Twostick
Still wishing...
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Still wishing...
Joined: May 2003
Posts: 6,559
Downtown Roebuck Ont
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This is from the Hydroplane Racing League rule book. http://hrlhydroplane.com/wp-content/uploads/2016/03/HRL-Annex-V7.pdfCAMSHAFT & VALVETRAIN
The ONLY 2 camshaft accepted are:
Option 1: HRL Camshaft. It MUST be purchase through the Hydroplane Racing League –
HRL, Coordinator 450-371-6144 ext. 224 – Anne-Marie Leboeuf
Option 2: Comp Cams # 12-675-4
You can buy it directly from any distributor
A. Stock diameter magnetic steel solid flat tappets lifters. Maximum size 0.842” No
hydraulic lifters
B. Stock size push rods only. Size 5/16” all the way. (No titanium or exotic material)
C. No mushroom or roller tappets. No rev kits.
D. Double roller or standard timing chain only. No gear drive or belt drive.
E. Roller rocker arms allowed. NO shaft rocker arm systems. 1.50 Ratio Only
F. Stud girdles allowed.
G. Valve Springs - Any valve spring may be used, Maximum size: 1.250’’ (+ or – 0.010’’)
diameter
H. Spring retainer: steel only, no exotic material
I. No cam roller bearing allowed
J. Standard diameter cam bearing only
K. Any alteration of the original form is prohibited. They run SBC with solid flat tappets for 5 mile at about 7200 RPM when the prop is in the water and flash 10,000 if it comes out of the water. My machinist builds these and one of his 5 litre engines holds the 5 Mile Closed Course World Record for MPH. He doesn't have camshaft problems and his favorite oil is Valvoline 15/40. Kevin
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Re: Flat cam
[Re: dvw]
#2403992
11/15/17 03:07 PM
11/15/17 03:07 PM
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Joined: Dec 2011
Posts: 257
Way North Idaho
1KoolBee
enthusiast
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enthusiast
Joined: Dec 2011
Posts: 257
Way North Idaho
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A couple of things I see. Shiny bearings speaks of oil film break down. Cam bearings, oil pump, and drive bushing are all damaged. Looks like there wasn't enough film strength, lack of proper oil flow or inadequate oil for the job.
Doug I agree....there's too much else going bad here to just be the cam, and if not corrected, it will happen again roller or not.
'68 Bee 383/TF/Factory Air...high school sweetheart
'67 GTX Clone project,500 six pack,Hemi4-speed,Dana
05 Dodge Viper, 505 V-10, 6-speed Tremec
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Re: Flat cam
[Re: BradH]
#2404084
11/15/17 06:10 PM
11/15/17 06:10 PM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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How high can a typical BBM HR setup spin before the extra weight of the roller lifters starts to become a limitation? I know some people have used (made?) restricted plunger-travel HRs to squeeze out more RPM. But that's not the "normal" build, is it?
As I've gone faster over the years, my required RPM ceiling has also been raised quite a bit... 5800... 6400... 7000... 7200. How far up my incremental RPM steps could a HR have taken me? Weight is not much of a factor on stock builds, but becomes an issue with hi RPM race motors. Everything has to be bigger / stronger ( and heavier ) just to be able to handle the spring loads. And the spring loads aren't variable - same big hit at idle as at ......rpm. And while those spring loads are going up, life expectancy is going down. All things to consider when choosing a cam for a particular application. And IMO, the OP's failure is not in that equation and should not be part of the cam choice decision.
Fastest 300
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Re: Flat cam
[Re: CSK]
#2404275
11/15/17 11:28 PM
11/15/17 11:28 PM
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Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
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Just to point it out, in case it got lost in the fog......
The OP had no symptoms or indications of any kind of cam problem.
We spoke on the phone and he told me the last time he had the car at the track it made its best runs.
Why the pan was off was to look for the cause of the erratic, and lessening oil pressure(and I believe that problem has been identified).
He noticed the irregularities on the cam lobes when the pan was off.......but it wasn't anything he was looking for.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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