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Tech,
I am amazed at the effort you show to people you dont even know. YOu must have spent 8 hours on these post. I am not even building a sbc and yet I copied these posts and saved them as a separate document. Whether this person uses your advice or not, I want to thank you for the excellent post.
Many thanks!
TechInspector has a lot of good advice. If you decide against a roller cam, just make sure you add the appropriate zinc additives (EOS or other such products) to your oil and break it in properly. New oil formulations are not good for flat tappet cams. And IMO, the XE-274 is a little big for a 350 if you want to have a street-friendly driver.
Tech is very knowledgeable on this subject. I built a 383 based on his recipe and it screams. I used the comp hyd roller 286 magnum(230/230 @ .050)
I have built many engines and one thing that I have discovered is that from the very beginning, you must really think long and hard about what really you intend for the car. Are you really going to put 10,000miles on it? does it have ac and other power accessories?
As far as sound is concerned, I agree with tech. Hyd (flat tappet or roller) will never sound like the solid roller that I just put in a recent 427 ford build( 254@ .050) NEVER.
It is not necessarily the camshaft itself that is the culpit for poor driveability (aside from low vacuum) It's the things that complement the camshaft requirements ie...high compression, high stall, lowgears ect...
Comp created those thumper cams specifically for sound. I have put them on the desktop dyno and they inferior to other cams from a performance stand point.
I probably will never install another flat tappet again. After the last wipeout, too $$$
I like the sound of solid rollers as you can hear the valvetrain components clearly. Plus, solid rollers separate the fairweather corvette dorks from real muscle car enthusiasts!!!!!
WOW again techinspector1 !
I can't say enough how much I appreciate this information you gave me and the time you've taken to put this info together for me.
You've sold me on the hyd. roller set up. With my luck I'll screw something up and wipe out a cam/lifter then start kicking myself. I don't want to pull the engine and all the crap that goes with it to re-do what I tried so hard not to screw up.
I'm going to study, make notes and search all the part numbers you gave me, (I really appreciate the links and part numbers).
Again you clarified so much for me and I can't express enough for the time you took to help a complete stranger.
I will keep this thread so I can refer to it often, and of course the other members that have also posted. I value all your opinions. You guys have seen a hell of alot more then I'll ever get to experience and thats your experience I must learn from.
Like they say- "You get what you pay for, You pay for what you get"
Sincerely thanks.
Hi Guys,
Found these two cams, I will give you the numbers. This is what is hard for me to understand, so with the info earlier in this thread of my engine, car combo,
basically-
355, hyper pistons(d-cup), 9.0:1 comp., 3500 lb. car, 3.89:1 gears, 2200 stall.
Other info in above posts, don't want to repeat too much.
These two roller hyd.cams:
#1-dur@.050 234/238 - adv. dur. 296/300 - 112 lobe sep. .539 int/.548 exh.
#2-dur@.050 226/234 - adv. dur. 258/256 - 110 lobe sep. .525 int/.532 exh.
With these specs what can I expect with these cams for a street engine, manners, sound, one hve more torque or hp than the other?
Don't even know if this is a fair question.
Thanks if anyone can help.:o
I have a question about the valve adjustment. Techinspector1, you said to adjust the rocker arms 1/8 turn after all the slack is removed from the valvetrain(zero lash). I have always adjususted 1/2 turn except when using Competition Cams Pro Magnumroller lifters. The Pro Magnum is basicaly a race lifter. The rest of the Comp Cam line is 1/2 turn after zero lash. G.M. recommends :eek:3/4 to 1 turn after zero lash. I'm just a little concerned why you would say to adjust the valves 1/8 turn without knowing which lifters are going into the engine.
Quote:
Originally Posted by techinspector1
It was brought to my attention on another forum that there are some lifters that want only 1/8 turn. This is only the static adjustment anyway, just to get you in the ballpark to crank the motor and for the cam run-in. You are expected to do a hot lash after break-in and can set the preload anywhere you think is right. I have read lately that some fellows are using 1 1/2 turns after the slack is removed.
Wow 1 1/2 turns. Maybe they should just use a solid lifter cam. Thanks for clearing that up.
Cam #2 is the better choice but I would want a little more stall--at least 2400. Cam #1 is a little larger than you want with 9:1 compression. That cam would want at least 10:1 static compression to take advantage of the additional duration. In addition, you would need more stall, more in the area of 2800-3000. I think you would like the street manners better with cam #2. Cam #1 would be a better choice for a 383 or 400.
Thanks Lynn
Cam -1 was used in 383 build with a 10:1 compression (Edelbrock 2201)
Cam -2 was recommended to me by Howard Cams, gave them by combo info and is sending it out.
I just find it hard to look at these numbers and be able to read what application it would fit, you apparently had no problem.
Thanks!
It just like anything else--the more you study this stuff, the more you learn about it, and the more you can pass on to others. I suppose it has something to do with all the years I spent teaching.
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