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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 82Shortbed on August 02, 2008, 03:21:31 am
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I'm sure most people have heard this cam one time or another but may not know it, but I was curious to know if anyone has used this cam in a truck, how well did it perform, and how did it sound idling? I've heard several opinions on the idle either being nice and smooth and some saying it has just enough lope so you know it's not a stocker.
Anyhow, I want to stick this cam in my 350, it has fresh vortecs with a valve job and shaved to a 60cc chamber, flattop pistons, I've been told with a .039 head gasket that will put me right at 10.5:1 compression, the rest of the bottom end is stock with a vortec performer intake, a q-jet, and MSD distributor and 6A box. My truck has 3.42 gears as well. here's the cam specs as on the box
Lift .447/.447
Duration 290/290
Duration @ 0.050 - 222/222
LC/114
Opinions would be appreciated
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My thought is that it is too small & too wide of lobe separation. You have a good set-up going there. Something like 230*-236* duration @.050 & if the guides have been cut....about .525-.535 lift. If they haven't been, .500 is about all you can go. Check out the Comp cams beehive springs/retainers, they help with the clearance issues. Ground on a 110-112 lobe center. Honestly I would go a little bigger/tighter lobe sep. than this, but I checked your other posts for your goals & this should do about right for you. This should bleed off enough cylinder pressure at low RPM's to run pump gas & sound kinda nasty too. A 1800 or so stall converter should be about right. Just my Two cents worth, Lorne
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That set up needs a cam more like this one (http://store.summitracing.com/partdetail.asp?part=SUM%2DK1107&autoview=sku)
Or if you want a smoother idle this one (http://store.summitracing.com/partdetail.asp?part=SUM%2DK1105&autoview=sku)
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After talking to some people at work today, they suggested a couple of other cams with shorter advertised durations with similar durations at 0.050, they were tellin me that those are better because they're not as "lazy" or whatever, anyhow, here's a couple of suggested cams I like
Comp High Energy 268 Single Pattern .454 268 218@0.050 110/106
Comp XE262 .462/.469 262/270 110/106
Summit 1103 - .442/.465 214/224 @ 0.050 112LC
I've read that vortecs like staggered pattern camshafts better because the extra duration on the exhaust side helps clean the chamber out better because they're exhaust flow needs a little help. I want all the suggestions I can because I only want to do this once! My goal is at least 350hp, 375 would be great. I mess with desktop dyno, but I have no clue how accurate it is, and it sits me around the 370-380 range with a variety of camshafts, I notice the more duration it has, the lower my torque is, which I don't want to sacrifice that much mainly because I want it to pull when I hit the throttle, I have NO plans on towing with this truck, but 350hp/370ft lb would be SWEET, I've never had that kinda power before, so I'd enjoy it.
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Although those cams you listed have different profiles they are pretty mild camshafts and to realistically see 375 hp you're going to need a much more aggressive cam.
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Did you ever see the movie Planes, Trains & Automobiles with John Candy & Steve Martin? In there is a part...."Your going the wrong way...Your going the wrong way". You have the compression, head flow & intake to make a VERY good daily driver that will put a smile on your face every time you hit the gas. Pick a cam in the size Vile (the top one ;D) & I have advised or better yet, call a cam company & give them your details. I would be shocked if their advice was even close to the "buddies" at work. Those smaller cams will do several things....increase cylinder pressure, which is good if you have low compression (which you don't, if it's truly 10.5 to one) this can cause pinging. The larger duration will bleed some of the compression at low engine speeds to help this. Also, I feel you will leave yourself well short of your HP/torque goals, the last couple aren't much more than a stock cam, the engine will have be neutered. The ADVERTIZED numbers mean NOTHING in in picking a cam, NOTHING. The .050 numbers are measurable on the cam & fact. As I said just my Two cents... you asked for opinions. But sometimes more opinions isn't always better, call a cam company if you don't know which way to go. Your performance goals are in that engine, the cam is the brain of it all. Lorne
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When you are really stumped on the cam to go with, call as many cam companies as you can think of with your combo specs and honest goals. Call as many as possible and go with the size they all seem to gravitate towards. Comp, Crane, Lunati, Isky, Crower, Engle, Howard, Reed, Schneider; give 'em all a ring.
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you'll notice for those flat tappet hydraulic cams I recommend the summit cams quite often. The brand names mean NOTHING. Edelbrock recently admitted to me they don't even make their own cams. They're just sticking the name on it. Hence why their technical data is contradictory and is flat out wrong in many circumstances. the guy on the other end of the phone many times will have never opened up and built an engine in their life. Listen to the guys here who have the experience with building LOTS of motors.
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I actually like having those bigger cams suggested to me as I was worried honestly if they'd been too much cam for me. I'm waiting on emails from Comp and Lunati, but hey, I do work for an auto parts store, so I could milk the clock and call some cam guys during the week! But the Summit 1107 has caught my attention big time!
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Guys, don't know much on the heads he has but where is coil bind a problem? I think Lorne may have answered it by cutting the guides. I know with my Trick Flows I had to change the springs to accomodate my new roller cam. Just a thought, may not apply here
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coil bind will depend on the cam and the spring that's installed. If you need to check it set the installed height of the spring in a jig or a spring tester and compress it. It should have an open pressure to match the cam specs and not bind. Most cam manufacturers will recommend the correct spring unless they don't make one in which case you have to hunt for one that matches the specs. If you are eliminating rotators (always a good idea) you also need to make up for the difference and measure the installed hieght.
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Gettin' a little off topic here, but, Vile, who do you recommend for retro-fit hydraulic roller cams? Who did you use for your 454? Is there any way to do it (cam, lifters, pushrods, springs) for much less than $1000?
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For my 454 I used the Edelbrock roller cam. They were the only ones with the grind I needed. click (http://store.summitracing.com/partdetail.asp?part=edl-2262) and these lifters click (http://store.summitracing.com/partdetail.asp?part=EDL%2D97443&autoview=sku) I don't think you'll really have a huge problem from manufacturer to manufacturer though but here are some suggestions when thinking about switching to a roller
Heavy duty thick timing cover.
Machined torrington bearing cam gear and retainer.
Lock plate
Double true roller chain
Cam button
correct length pushrods
guide plates
roller rockers
appropriate springs
It definitely makes a huge noticeable difference.
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Thanks for the response, Vile, I'll post further questions on this subject in another thread.
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Well, today, I called Comp, Crane, and Lunati, and here are the results
Lunati
Voodoo 60102 - .468/.489 219/227 @ 0.050 112/108
Bracket Master 00017 - .460/.460 224/224 112/108
Crane
113532 - .473/.486 224/230 110/105
Comp
XE274 - .490/.490 230/236 110/106
Thumpr 12-600-4 - .479/.465 227/241 107LS, he didn't tell me the intake centerline
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OK, so it looks like these guys are steering you toward something in the range of the Summit K1105, like Vile suggested for a smoother idle than the K1107.
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The past couple of days, the 2 Comp cams are the ones I've narrowed it down to. The thumpr cam sounds SWEET, I listened to them on comp's site and youtube. But I know I gotta have some performance too, so the XE274 looks very good to me as well...... Tsk tsk
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you'll notice for those flat tappet hydraulic cams I recommend the summit cams quite often. The brand names mean NOTHING. Edelbrock recently admitted to me they don't even make their own cams. They're just sticking the name on it. Hence why their technical data is contradictory and is flat out wrong in many circumstances. the guy on the other end of the phone many times will have never opened up and built an engine in their life. Listen to the guys here who have the experience with building LOTS of motors.
Very True Ville, the Majority of the Brand Name Manufacturers only make certain parts in house, with the smaller items or even the Larger Production Run items(Things that have been in Production for years) are produced by an outside vendor, and then shipped to the Brand Name Company for their Packaging..... Larger Parts Houses(JEGS/SUMMIT/JC WHITNEY/Etc) will approach those Vendors to cut out the Middle Man, when they want to offer their Store/Catalog Brand Items under the Bigger Name Brands.... One of the things I learned from being in Auto Parts Sales, and Through Various Automotive Venues, each of the Larger Brand Name Companies have items that they just relable with their names on them....
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Hey shortbed, here is a thought. If you have a cam that doesn't necessarily sound mean but really is (aka sleeper) that could be fun. I've always thought it has been pretty cool to be able to outrun the other guy and not sound as if I should.
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Well, I think with the power I want, that a small cam would kill my power. I almost got my mind set on the XE274. It has enough overlap to give me the sound I want, I heard it on youtube. I don't want a sleeper sound, I wanna be heard!
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Do you know what kind of exhaust was on the you tube vehicle? That will make a difference as well.
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The one on youtube had different heads and I would say different exhaust. I'm running Longtubes and 2.5 H pipe exhaust with Flowmaster Super 40s. So I know I should do some ground pounding because I do not have tailpipes. The camaro it was on was ran all the way back to the rear.
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The XE274 will give you a nice chop. I have the XE268 and at idle in Park it has some lope but still idles fine at 850 or so RPM. When I drop it into Drive though and the revs drop to around 700, it really chops. Sounds like it wants to die and if the idle was any lower it probably would. When at a light with my foot on the brake it shakes the truck around and does this little surge every now and then. I quite like it. So the 274 you should not be unimpressed with as far as that goes.
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The XE274 will give you a nice chop. I have the XE268 and at idle in Park it has some lope but still idles fine at 850 or so RPM. When I drop it into Drive though and the revs drop to around 700, it really chops. Sounds like it wants to die and if the idle was any lower it probably would. When at a light with my foot on the brake it shakes the truck around and does this little surge every now and then. I quite like it. So the 274 you should not be unimpressed with as far as that goes.
Any sound clips to give me somewhat of an idea?