Big Block cam
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Big Block cam
Ok here goes. I think I am going to do the cam this winter and it will either be a solid or solid roller. Over the years I have seen some bad things about solid rollers and their durability on the street, oiling problems etc. Is this still the case or not. I am only looking for 550-600 horesepower with the 502 so I wouldn't have to go too radical at least with the roller. I have iron heads with 8.75 to 1 compression and rectangle ports. I will have to have the heads converted to rocker studs instead of the non-adjustable valvetrain so I can probably mill the heads to 9.5 to 1. Will the flat tappet be more or less durable than the roller and how much more horsepower will a roller make than a similar flat tappet. Also what is the cost difference I should expect. Thanks.
Safety Car
Joined: Mar 2001
Posts: 3,725
Likes: 0
From: Rochester NY
Re: Big Block cam (69ttop502)
69ttop502,
Comp Cams is making an extreme duty roller lifter for street driven roller cams. But spring life is also a problem for solid rollers. With the power levels you want to make a hydraulic roller cam might be the ticket. Good power but you never have to adjust the valves. My SBC with a roller that I drove on the street had the covers off every 100 miles or so to make sure nothing was going bad.
Joe
Comp Cams is making an extreme duty roller lifter for street driven roller cams. But spring life is also a problem for solid rollers. With the power levels you want to make a hydraulic roller cam might be the ticket. Good power but you never have to adjust the valves. My SBC with a roller that I drove on the street had the covers off every 100 miles or so to make sure nothing was going bad.
Joe
Race Director
Joined: Feb 1999
Posts: 16,978
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From: In Dreams There Is Truth Ohio
Re: Big Block cam (69ttop502)
You have to use the Comp Cams solid roller lifters designed specifically for the 502. Think Engle also has a set for the 502. The 502 lifter bores are longer than the 427/454 bores, therefore you have to use longer lifters or machine the bores. The lifters are around $450.00. DO NOT USE std. solid roller lifters on the 502.
Check out the Com Cams 288-AR.
Check out the Com Cams 288-AR.
Race Director
Joined: Nov 2000
Posts: 11,872
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From: Waterloo ontario Canada
Re: Big Block cam (69ttop502)
I spent about $1500 CDN changing from solid flat tappet to roller and I never like the roller cam as well. I was told by my speed shop that they never really noticed any difference in flat or roller cams. For the dollar a good solid roller cam is hard to beat. My valves stay adjusted. I adjust them in the spring when the car comes out and don't need to touch them again.
A Crane cam is about $165CDN and the lifters are about $100. For the roller cam and lifters I paid $800 then needed the spring, retainers, keepers and I wanted a stud girdle which also needed longer rocker arm studs. It soon added up.
But I have bragging rights. It is a roller motor.
A Crane cam is about $165CDN and the lifters are about $100. For the roller cam and lifters I paid $800 then needed the spring, retainers, keepers and I wanted a stud girdle which also needed longer rocker arm studs. It soon added up.
But I have bragging rights. It is a roller motor.
Le Mans Master
Joined: Mar 1999
Posts: 6,744
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From: delmont pa
Cruise-In I Veteran
Cruise-In II Veteran
Re: Big Block cam (69ttop502)
never run a solid roller cam without a rev kit to hold the lifters in place because if you lose a rocker or a push rod the lifter can jump out of the bore and the turn 90 degrees fall back down the lifter bore and presto you have BIG trouble. a friend of mine just found this out with his 510 blower boat engine when he broke a rocker stud. also the rev kit will keep the lifters on the cam at all time even at idle. that is the advantage of a hyd roller the lifters never leave the cam lobe:chevy
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Re: Big Block cam (clem zahrobsky)
Thanks for the information everyone. GDaina I have the Gen V 502 with the hydraulic flat tappet cam so I could be wrong but I don't think I have the taller lifter bores. I guess I will go flat tappet solid but help me out again here. In order to get around 600 horsepower I probably need somewhere around .600 lift and duration in the mid 250's at .050 so do I have enough static compression to run this healthy of a cam and would the spring pressure necessary to run this cam have adequate durability. Thanks again. Norval what were your roller and flat tappet specs, and GDaina what are you running?
Safety Car
Joined: Aug 2001
Posts: 3,892
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: Big Block cam (69ttop502)
I do not think you have enough compression to run the 288, maybe try the 280. The Comp catalog calls for 10 to 1 for the 280, let alone the 288. I would call Comp and ask them. I am running the 280 in a 600 HP 454.
Race Director
Joined: Nov 2000
Posts: 11,872
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From: Waterloo ontario Canada
Re: Big Block cam (69ttop502)
The flat tappet crane cam I loved was F 256/3634-2s-8 It had .618 intake lift and 256 @ .050 and 638 exhaust lift and 264@ .050 It had 105 lobe centers. This cam really pulled in the mid range and would effortless take me to 7500.
I replaced it with a comp cam roller solid that Lingenfelter advised me to try. I hated it but after $1500 for everything including a stud girdle I stuck with it.
.623 lift 236@.050 intake 244@.050 exhaust 112 lobe centers. This cam has a good idle vacuum but it is all done by 6500 with no mid range charge.
I replaced it with a comp cam roller solid that Lingenfelter advised me to try. I hated it but after $1500 for everything including a stud girdle I stuck with it.
.623 lift 236@.050 intake 244@.050 exhaust 112 lobe centers. This cam has a good idle vacuum but it is all done by 6500 with no mid range charge.
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Race Director
Joined: Feb 1999
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From: In Dreams There Is Truth Ohio
Re: Big Block cam (69ttop502)
[QUOTE]Thanks for the information everyone. GDaina I have the Gen V 502 with the hydraulic flat tappet cam so I could be wrong but I don't think I have the taller lifter bores. [/QUOTE/]
The 502 block has the tall lifter bores. The hydraulic roller lifters made for the 502 are tall. If you go with a solid roller cam, you HAVE to get the solid roller lifters made for the 502 from Comp Cams or Engle
I am running 10.4 C.R. If you got the 502/502, your C.R. may be 9.75, not sure.
I am running the Comp Cams 288AR solid roller, Gen IV cam. Had to modify the timing cover to make it work. There are Gen VI solid rollers on the market from Comp Cams, Engle and others. Since I had the cam, I decided why buy another.
The specs are .623 gross lift, duration @.050 246 degrees, 110 centerline. Great power and torque through out the entire power range. Also am using factory tri power, and older al. sq port heads, pocket ported, triple angle grind.
If you go with a new cam, u have to get the springs recommended for that cam. DO NOT USE existing springs unless the meet cam spec pressure, when open.
The 502 block has the tall lifter bores. The hydraulic roller lifters made for the 502 are tall. If you go with a solid roller cam, you HAVE to get the solid roller lifters made for the 502 from Comp Cams or Engle
I guess I will go flat tappet solid but help me out again here. In order to get around 600 horsepower I probably need somewhere around .600 lift and duration in the mid 250's at .050 so do I have enough static compression to run this healthy of a cam and would the spring pressure necessary to run this cam have adequate durability. Thanks again. Norval what were your roller and flat tappet specs, and GDaina what are you running?
I am running the Comp Cams 288AR solid roller, Gen IV cam. Had to modify the timing cover to make it work. There are Gen VI solid rollers on the market from Comp Cams, Engle and others. Since I had the cam, I decided why buy another.
The specs are .623 gross lift, duration @.050 246 degrees, 110 centerline. Great power and torque through out the entire power range. Also am using factory tri power, and older al. sq port heads, pocket ported, triple angle grind.
If you go with a new cam, u have to get the springs recommended for that cam. DO NOT USE existing springs unless the meet cam spec pressure, when open.
Burning Brakes
Joined: Feb 2001
Posts: 854
Likes: 0
Re: Big Block cam (69ttop502)
Bill. Send me a detailed list of what you have now and or going to add, and i'll run this past the guy who built my "383".He's the one that tested the "baffles" first with the 434BB. Because of the freer breathing,he's adding a special dual plane manifold and moving up to a 1050 Dominator. Let me know. Thanks, JCL :cool: :cool: :chevy
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Re: Big Block cam (JCL)
Norval and GDaina thanks for your input, that is interesting that you liked the flat tappet better. I will probably go that route because of the lower cost. Now I need to figure out if my low compression is going to give me a problem. I read an article on the Merlin 509 and with 9 to 1 compression and iron rectangle port heads they used a Crane solid flat tappet with .579 lift and .050 duration of 256, so I guess its possible to run a pretty healthy cam with that compression. They dynoed that engine at 580 horsepower with smaller diameter headers than recommended. Jim I feel awful that I haven't gotten any pictures to you yet but I finally did take some so as soon as I can figure out how to scan I will get them to you and my thoughts on your baffles. I am really enjoying the hell out of my exhaust and the car runs great and sounds just perfect. Thanks for the help I will E-mail you my specs and Will get you those pictures. Thanks guys.
