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Author
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Topic: Solid Flat tappet vs solid roller cam? (kinda long)
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MrWesson22
Gearhead Posts: 1295
From: Dacula, GA
Registered: Sep 2000
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posted 05-03-2001 12:29 AM
 
Hopefully towards the end of the summer, the cleveland is getting new heads/intake/cam/carb. We're using 2V heads with 4V valves... the guy doing my porting gets around 280cfm @ .600 lift with these and says they have great midrange flow and power on the street. He owes me a favor and is doing the headwork for practically nothing. We'll do it right with a good valve job and all that. We're also going to use a Weiand Xcelerator single plane for the 2V heads opened up a little and a Holley 850DP. We're looking at Crower 1.8 roller rockers as well. The car has 10.6:1 CR (I believe), hooker longtubes, a full MSD ignition, holley mech. fuel pump... I'll be running 3.89 gears. The goal is 425-450hp on pump gas with as much torque as possible. I know I can get there with a flat tappet cam, but would it be worth the extra cost/hassle to go for a roller conversion? We are going to get a custom grind cam based on what the heads end up flowing, so that's not really the question right now though input would be appreciated. I guess I'm just wondering how much extra power a roller cam with a similar grind is worth over a similar flat tappet and whether it really is easier on valvetrain parts enough to warrant the extra cost in this application. I apologize for being so long winded and appreciate any input y'all have. If any more info is needed, just let me know. Thanks! ------------------
Neal
Member #723
[email protected] AIM: MrWesson22 69 Gulfstream Aqua Grande
351C/Toploader 4sp
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MrXerox
Gearhead Posts: 349
From: Oklahoma City, Oklahoma
Registered: Nov 2000
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posted 05-03-2001 01:32 AM
I am building an IDENTICAL setup to what you have Neal except I have the 4V quench heads with the boss screw in stud conversion done to them. The cam Alex picked out for me was the Comp Cams 32-771-8 which is a solid roller that boasts a 244 @ .050 and .623 lift with a 110 LSA. A roller is the way to go if you can swing it dollar wise as ANY less friction in a motor is certain to make more power. This cam will help you bleed off some of that compression as well to hopefully run on premium pump gas  I am going to run a C-6 with a 3500 stall so Alex might have a better suggestion for your 4 speed setup...?
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MrWesson22
Gearhead Posts: 1295
From: Dacula, GA
Registered: Sep 2000
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posted 05-03-2001 09:42 AM
Yeah, that's what I was leaning towards too. Anyone know how much $$$ Comp Cams' roller conversion is running these days?------------------
Neal
Member #723
[email protected] AIM: MrWesson22 69 Gulfstream Aqua Grande
351C/Toploader 4sp
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kid vishus
Gearhead Posts: 7251
From: middle of NC
Registered: Oct 2000
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posted 05-03-2001 10:28 AM
My only input is depending on what the heads end up flowing and where the peak flow is, should dictate what ratio rocker arm you use. If the heads stopp increasing cfm at .600, then .620 to .650 lift is where I would peak the cam at. Using .700 lift wont gain anything but wearing out springs faster in my opinion if the heads dont flow up there.
I wouldn't buy 1.8's for the sake of buying 1.8 rocker arms. I would rather use a lower ratio rocker arm and keep the geometry in line easier than use a long rocker arm and put more un-necassary strain on the springs. My current motor has 1.6 rockers on the intakes on and 1.73's on the exhaust. That gives me .605 lift on the intake, and .650 on the exhaust, and it works real well like that.
Also, I think the 850 might be a little much for a street motor. At least I never had much luck when I tried to run one. I found a 750 dp worked much better. Just my opinion.
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MrWesson22
Gearhead Posts: 1295
From: Dacula, GA
Registered: Sep 2000
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posted 05-03-2001 11:07 AM
I asked Neil about that (the guy doing my heads) as 1.73 seems like plenty to me. He said he really did see a noticeable gain on the motor with these heads with the 1.8s. I'm still not decided on the carb either, I do know it'll be a holley DP and I'm taking it to someone that KNOWS the carbs inside and out to get him to set it up for me.------------------
Neal
Member #723
[email protected] AIM: MrWesson22 69 Gulfstream Aqua Grande
351C/Toploader 4sp
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MrXerox
Gearhead Posts: 349
From: Oklahoma City, Oklahoma
Registered: Nov 2000
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posted 05-03-2001 12:21 PM
Why dont you have your heads machined for screw in studs and you will not need the "conversion". I would never trust anything other than studs with an aggressive roller grind like you are wanting to run....? I would listen to the kid on the rocker ratio as well...anyone who throws together a cleveland using bit and pieces that runs in the 10s must know his stuff
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Rustang1
Gearhead Posts: 110
From:
Registered: Nov 2000
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posted 05-03-2001 12:26 PM
Based on a friends expensive learning curve, if you go roller, don't scrimp on the lifters! The prices are cheaper for a reason!------------------
1968 Mustang,Clevor,C4
1969 Torino 351C 4spd
1978 F150 460 C6
1978 F150 351W C6
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Butch Jennings
Gearhead Posts: 637
From: No. California
Registered: Apr 2000
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posted 05-03-2001 01:27 PM
My experience has been that rollers require more maintenance and are generally harder on valve train parts due to more aggressive profiles and higher spring pressures. I've made real good power with flat tappet cams, I'm not saying don't run a roller, but unless you're willing to put the time in on maintenance....ie: checking spring pressures, staying on top of lash, looking at pushrods and rockers on a regular basis, I'd stay away from a roller. They will beat a set of lifters to death in no time if not properly looked after, I don't care who's lifter you use. Properly maintained, a roller is the way to go....it's all a matter of how dedicated you really are to keeping things right. Not that flat tappets don't require maintenance, just not to quite the same extent. I regularly check everything out on my flat tappet motors too, but I find that they require new springs way less frequently and they cost anywhere from 1/2 to 1/3 as much as the roller springs....especially if you use a stud girdle on the flat tappet combo, it seems like overkill, but a stud girdle keeps everything in check. That's my 2-cents (or maybe a nickel) ------------------
Butch
460 powered 1967 Comet Cyclone
10.27 @ 129.997
Butcher's Home Page
"Friends don't let friends drive Chevys"
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Gary
Gearhead Posts: 726
From: Sarasota, Fla. USA
Registered: Jun 99
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posted 05-05-2001 06:39 AM
Flat tappet with roller rockers are less hassel cheaper too. Or depending on what you plan to turn your engine to, a hyd roller cam
is a pretty much put it together and forget it deal
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MrWesson22
Gearhead Posts: 1295
From: Dacula, GA
Registered: Sep 2000
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posted 05-06-2001 10:53 AM
I appreciate all the info. My question stands -- how much power is a roller cam of a similar operating range worth over its comparable flat tappet? And how much money am I realistically talking about to do the conversion and do it right?------------------
Neal
Member #723
[email protected] AIM: MrWesson22 69 Gulfstream Aqua Grande
351C/Toploader 4sp
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Dave_C
Gearhead Posts: 1123
From: Gadsden, Al
Registered: Aug 99
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posted 05-06-2001 01:04 PM
Well, time foe me to be the odd man out.I would *never* go back to a flat tappet after owning a roller. Mine is in a 383W stoker with Windsor Sr iron heads, sees 7000 rpm all the the time, never any problems. No valvtrain wear at all. When I first put it in I checked the lash every 25-30 passes. Now I check it every 150-200. Reason is it never changes. I run a stud girdle. With it in place the rockers can't loosen on their on. The only way the lash can change is through wear. If the rocker geometry is correct and the right springs are used there will be no wear. Correct length pushrods and the right springs are the key. You don't have to run killer springs. My springs are good for two seasons. Mine measure 200 lbs on the seat and 510 lbs open. For a car that spends a fair amount of time at the track I would say go for. The cost is not cheap on the intial investment, but worth it in the long run. Don't really know on the power comparison. A friend of mine has a similar motor to mine with a flat tappet cam, same car weight. I do have more compression (13:1 vs 11:1) And my car is 3 tenths and 5 mph faster in the 1/8. Costs:
Comp Cams custom roller. .628/.630, 262/272 @ .050 104 lca. $275. custom costs the same as off the shelf
Comp roller lifters: $280. Stay away from the off brands like CAT, ($110)
Comp pushrods: .200 short (7.950) $110
Doug Herbert Performance house brand roller valve springs (rumour is they are made by Isky). 1.500"/.735 dual springs $90
Doug Herbert titanium valvespring retainers $60
Comp Cams 10 deg valve stem locks. $30.
Probe stud girdle. $110. The stud girdle and titanium retainers are optional, but the 10 deg locks are not. Keep in mind that if you are starting from scratch you have to buy pushrods, springs, retainers etc. The only real difference is the $550- $600 for the cam and lifters vs $160 for a flat tappet cam/lifters. Later, David Cole
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Moneymaker
Administrator Posts: 29200
From: Lyons, IL, USA
Registered: May 99
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posted 05-07-2001 01:41 PM
Roller cam! You can pay me now, or you can pay me later!  Roller will ALWAYS make about 20 to 25 more HP than the comparable flat tappet. There is no conversion by the way. You just buy a roller cam and appropriate kit or parts. (unless you were refering to a hydraulic roller YUK)Maintanance is no different than any higher RPM engine. You have to periodically check and set the valve lash that's all. No big thing. ------------------
Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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n2oMike
Gearhead Posts: 3058
From: Spencer, WV
Registered: Jan 2001
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posted 05-07-2001 01:57 PM
Just be careful running an agressive roller on a car that sees a lot of miles and won't see a lot of maintainence in the way of yearly or so valve jobs. Agressive rollers drop the valves on their seats pretty hard, so valve jobs don't last as long. Guides also get loaded more with all the extra lift as well. As for the rest of the valvetrain, it all sees more stress, but top quality parts should stand up to the abuse. The longer the duration of the cam, the more you stand to gain from going roller.Good Luck! ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/motorcitymustang/cmml/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
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oreozeus
Journeyman Posts: 1
From: Rocky River, Ohio
Registered: Mar 2006
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posted 03-11-2006 02:05 PM
THIS IS VERY GOOD INFO - I AM RUNNING comp rollers and I had a failure in one of my 572's - the wheel fell into the cam journal and the next time the lobe came around it pushed it right through the cooling jacket -
Yes rollers allow stiffer springs and last longer but if you run moderate rpm (6000) I would go with the non-rollers. a solid will rev fine and I know we all like to take our motors apart way before they wear-out a roller (150K) the real advantage to t aroller is the tappet opens quicker or "on the very edge or sise - this giving a longer duration on the valves - Is is worth it? Not unlless you have a 6000 rpm and over motor - Well I have one last word of advise - GO Cubs!! GJO My experience has been that rollers require more maintenance and are generally harder on valve train parts due to more aggressive profiles and higher spring pressures. I've made real good power with flat tappet cams, I'm not saying don't run a roller, but unless you're willing to put the time in on maintenance....ie: checking spring pressures, staying on top of lash, looking at pushrods and rockers on a regular basis, I'd stay away from a roller. They will beat a set of lifters to death in no time if not properly looked after, I don't care who's lifter you use. Properly maintained, a roller is the way to go....it's all a matter of how dedicated you really are to keeping things right. Not that flat tappets don't require maintenance, just not to quite the same extent. I regularly check everything out on my flat tappet motors too, but I find that they require new springs way less frequently and they cost anywhere from 1/2 to 1/3 as much as the roller springs....especially if you use a stud girdle on the flat tappet combo, it seems like overkill, but a stud girdle keeps everything in check. That's my 2-cents (or maybe a nickel) [/B][/QUOTE] [This message has been edited by Moneymaker (edited 03-11-2006).]
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V8 Thumper
Gearhead Posts: 4777
From: Phoenix, Arizona
Registered: Dec 2001
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posted 03-11-2006 03:33 PM
quote:
Originally posted by oreozeus:
Well I have one last word of advise - GO CHEVY!!
Dude, take is somewhere else 
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1965 GT coupe, 333ci aluminum headed/solid cammed stroker, four speed, 3.70:1 9" 12.58/110 on street tires, more to come;) All Blue Oval, no blue bottle
http://mustangsandmore.50megs.com/V8Thumper.html
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V8 Thumper
Gearhead Posts: 4777
From: Phoenix, Arizona
Registered: Dec 2001
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posted 03-11-2006 03:41 PM
Hmmmmm...   ------------------
1965 GT coupe, 333ci aluminum headed/solid cammed stroker, four speed, 3.70:1 9" 12.58/110 on street tires, more to come;) All Blue Oval, no blue bottle
http://mustangsandmore.50megs.com/V8Thumper.html
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n2oMike
Gearhead Posts: 3058
From: Spencer, WV
Registered: Jan 2001
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posted 03-11-2006 04:04 PM
Dang, that thread had been dead almost FIVE years! But, for the record, for a car that is expected to see a long service life without being torn down every year or so... Stay away from the solid rollers. Cheap
Heavy
Equiptment
Very
Yuseless ------------------
Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220 [This message has been edited by n2oMike (edited 03-11-2006).]
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