|09-05-2007 09:58 PM|
|awoodman||Well how do I tell what the springs on those modded vortec heads from summit are meant for? What do most budget builds for around 400hp with a 350 have for lifters? Roller or flat tappet? Either way, im going hydraulic.|
|09-05-2007 05:33 PM|
|DoubleVision||The roller cam I have is still for sale, less than half the price you`ll pay for a new one. Roller lifters can be reused, so can roller cams. Your looking at over $250 for just the cam itself. And the next lesson for today is, make sure you get the matching springs for the cam you get, you cannot use flat tappet springs on a roller cam. Whatever cam you get, get the springs that cam company recommends. While it can be confusing, whoever your ordering from will pawn flat tappet springs off on you and say "these are good for .600 lift! they`ll work great on the roller cam!" wrong, the fast opening and closing of a roller cam laughs at flat tappet springs and will create coil bind as well as early valve float in which both will result in failure.|
|09-05-2007 05:20 PM|
every one of the cam mfgr/grinders websites has a "how to select a camshaft" page of information...
on this comp link, click on each of the dyno graghs to see the details of the build, roller cams are the bottem section.....you want a cam with atleast 15"HG at 800rpm idle and hp peak around 5500 for a typical "street/strip" build
use the Knowledge Base link, at the top of this page....under engines/camshafts
|09-05-2007 04:45 PM|
|awoodman||My compression ratio will be right in the 9.75-10:1 range. I dont have head gaskets yet, so I can be anywhere in that range depending on what gasket I choose. Flat top pistons with 4 valve releifs, -5cc piston head. I plan on building the engine first, then getting a tranny and rear end. No emission testing that I know of..|
|09-05-2007 04:23 PM|
Do you know the compression ratio of the pistons in relation to the heads? Are they dished, flat top or domed?
What trans are you going to use and what rear end gears? Do you have any emission testing where you live?
Knowing a little more will help steer you towards a good cam selection.
Maybe someone can comment on This cam on eBay. It's a new takeout from a crate engine. Guy has 5 listed. ABout half the price of the Comp or Crane.
|09-05-2007 03:07 PM|
|awoodman||can anyone help me out? Id like to order the cam today if possible. Thanks|
|09-04-2007 07:16 PM|
|awoodman||Okay, so if I use these lifters, can I get away with a cam that costs maybe like $250 or less? What will I want for a cam that goes in my engine? Its a 355 with hyperutectic pistons, stock resized rods, the machined vortec heads from summit for $390 a piece assembled with a max valve lift of .550 in. and valve sizes 1.94 and 1.5, and a 700 cfm carb? I dont know what im using for a tranny yet, but the engine will got in a s10 for the street and strip. I want as much hp and torque as possible, with the car still being drivable on the road.|
|09-04-2007 04:44 PM|
Matching them to the bores is not necessary.
Only you can tell how each one looks and feels. If you take them apart and clean good and they are ok, go for it!
one a side note here, I have a good buddy that bought a new Chevy truck back in '96. I believe it is a roller cam engine. He has well over 240,000 miles and NEVER been apart. Trans is original too. (4L80E)
|09-04-2007 04:40 PM|
|awoodman||Is it a problem that I didn't mark the lifters and bores? Because I didnt know to do that when I removed them. Theyre in very nice shape visually and I would take each one apart and clean it thoroughlly and re-oil them and just use them on a nice hydraulic roller cam. What do you guys think?|
|09-04-2007 03:47 PM|
|DoubleVision||Read Jmarks post again, but I will say it for him. Do NOT waste your time on a flat tappet camshaft. You will pay more for a roller cam, but you are getting what you paid for. I have a comp roller cam for sale that has less than 5000 miles on it that works in factory blocks that came with a roller camshaft. There are few oils left that you can get that have zinc and other anti wear additives, without these additives a flat tappet cam will go flat in short order and the powdered metal will kill the rest of the engine and you will be starting over again. If you are interested in the cam I have let me know it`s going for a good price and there is nothing wrong with it, it will give you explosive low end torque as well as better gas mileage.|
|09-04-2007 03:11 PM|
|awoodman||so what should I do for the most power? Reuse the lifters with an aftermarket high lift cam or just buy a hydraulic flat tappet and high lift cam set?|
|09-04-2007 03:03 PM|
|09-04-2007 02:59 PM|
Roller lifters, in and of themselves, will give you almost no hp gain, all things considered. Where they really pay off is on very agressive cam profiles. They allow much faster openings and closings. The lobe on an agressive roller cam is almost a rectangle! LOL A flat tappet lifter will end up scraping the edges of the lifter on the cam lobe if you tried to use it on an agressive roller camshaft.
If you are going to re-use your old roller lifters, you MUST run them on a roller cam.
|09-04-2007 02:42 PM|
|awoodman||Will I even have any more power if I keep the old hydraulic roller lifters with a performance cam, versus buy a kit with a new cam, and hydraulic flat tappet lifters? I imagine that a new kit would be more wise, because my engine had 158000 miles on it, although the lifters are fine...|
|09-04-2007 12:48 AM|
Again, sorry for wandering off topic . . . the older I get the more I seem to do that!
You're right, there's lots to learn! I used to wrench on cars quite a bit when I was younger but for the last 20+ years I just haven't had time. A couple years ago I bought an old '74 chevy C-10 and my boys and I have had some fun wrenching on it. My 19 year old son drove it alot when he was 16-18 and now for some reason it's just plain "tired"! So now I'm thinking it needs a rebuild so I've rekindled my old gear head ways.
The weather here has been excellent the last couple weeks - 60s in the evening and 80s during the day . . . prior to that it was high 80s during the night and 100 to 100+ during the day! Just plain nasty!
McCook isn't the end of the world, but you can see it from there! <grin> Actually it's quite a hike west of me and quite a different climate - I'm in southeastern Nebraska, just south of Lincoln. This area is more green rolling hills, out west is more sandhills and stuff.
Well, back to trying to read this entire board in one sitting! <grin>
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