decided to switch cams what do ya think ????

[ton*loc]

well my build is

358 with flat tops 10.0 to 1, professional products port matched IM, vortec heads 2.02 1.60, balanced bottom end, th350 with 3000 stall, edelbrock 800cfm. 100 shot of juice occasionally




you think this cam is a good choice.

Grind Number: 286 H06
Operating Range: 3000-6400 RPM
Duration Advertised: 286° Intake / 286° Exhaust
Duration @ .050'' Lift: 230° Intake / 230° Exhaust
Valve Lift w/1.5 Rockers: .465'' Intake / .465'' Exhaust
Lobe Separation Angle: 106°
Max Lift Angle: 102° ATDC Intake / 110° BTDC Exhaust
Open/Close @.050'' Cam Lift: Intake - 13° BTDC (opens) / 37° ABDC (closes)
Exhaust - 45° BBDC (opens) / 5° ATDC (closes)

[Super73]

For a 100 shot, it's fine. Personally I would like to see more exhaust duration and or a wider LSA to aid in pumping losses on the bottle.

[hotrod 80]

I agree the spray will like a higher lsa . I think you are leaving some flow on the table with the low lift numbers . IMO lift is free power and the vortecs should flow to .500 .

[ton*loc]

that is the problem with the vortec heads they cant handle alot of lift. something to do with the retainers running into the valve seal/guide area with out even more machining. the machine shop said to run no more then .475 lift and this was the most aggressive cam i could find under those guide lines

[whatnow123]

Originally Posted by ton*loc

that is the problem with the vortec heads they cant handle alot of lift. something to do with the retainers running into the valve seal/guide area with out even more machining. the machine shop said to run no more then .475 lift and this was the most aggressive cam i could find under those guide lines

Look at the Comp Cams Magnum 270... 470 lift, 270 duration. I've heard nothing but good things about this cam and it's right under your lift recomendation.

[Super73]

ok. With out going over .475 lift..

Intake lobe # 5201 (224 @ .050 with .470 lift)
Intake Lobe # 5216 (230 @ .050 with .459 lift)
Exhaust Lobe # 5238 (236 @ .050 with .459 lift)


Now if it were me, I'd use the 224* lobe. See it's less duration yet more lift. It's excelerating the valve faster. Your going to retain a little more bottom end TQ and really not going to loose much up top.

So, if it were me, I'd have it ground like this:

224/230 106 Intake Center with a 110 LSA

Do you know what thickness head gasket you are running?

If your truly at 10-1 static cr, that grind would put you at 8.24 dynamic cr. I would love to see you mill the heads slightly to reduce the chamber by 2-3cc's to achieve as close to 8.5 DCR as posible. That's about the max I'd want to run on pump gas.

With the 230/236 combo, I'd again set it up a 106/110. This would increase over lap from 7* on the other cam to 13* with this one. At this point, heads should be milled to cut 5-6cc's out to achiece 8.5 dcr.

Again, you'll see a little more top end power with the 230/236 cam due to the added duration. But it would be probably 5-7hp and at a loss of TQ with the added overlap. That TQ is probably going to get you out of the hole better and net an equal ET. On the bottle you don't want to be letting that N20 escape out the exhaust valve either (not that I think you would loose much with the extra 6* of overlap).

[ton*loc]

Originally Posted by Super73

ok. With out going over .475 lift..

Intake lobe # 5201 (224 @ .050 with .470 lift)
Intake Lobe # 5216 (230 @ .050 with .459 lift)
Exhaust Lobe # 5238 (236 @ .050 with .459 lift)


Now if it were me, I'd use the 224* lobe. See it's less duration yet more lift. It's excelerating the valve faster. Your going to retain a little more bottom end TQ and really not going to loose much up top.

So, if it were me, I'd have it ground like this:

224/230 106 Intake Center with a 110 LSA

Do you know what thickness head gasket you are running?

If your truly at 10-1 static cr, that grind would put you at 8.24 dynamic cr. I would love to see you mill the heads slightly to reduce the chamber by 2-3cc's to achieve as close to 8.5 DCR as posible. That's about the max I'd want to run on pump gas.

With the 230/236 combo, I'd again set it up a 106/110. This would increase over lap from 7* on the other cam to 13* with this one. At this point, heads should be milled to cut 5-6cc's out to achiece 8.5 dcr.

Again, you'll see a little more top end power with the 230/236 cam due to the added duration. But it would be probably 5-7hp and at a loss of TQ with the added overlap. That TQ is probably going to get you out of the hole better and net an equal ET. On the bottle you don't want to be letting that N20 escape out the exhaust valve either (not that I think you would loose much with the extra 6* of overlap).

so you think some thing like this would be better ? its the only production cam i could find around your description.

http://www.cranecams.com/index.php?s...21&lvl=2&prt=5

[Super73]

With a 109 ICL, you would have to mill the heads 10cc to achieve 8.5 dcr..

Call Comp and see what they want to grind the mentioned cam.


Call Comp and see what they want to grind the mentioned cam.

[djracer]

You might want to call Chet Herbert cams. He is crazy cheap and will sell you direct.

[ton*loc]

seems to be mixed ideas on the subject i talked to a few people at nothern auto parts here in sioux city and ended up comming home with this one


Grind Number: 282 H06
Operating Range: 2400-6200 RPM
Duration Advertised: 282° Intake / 282° Exhaust
Duration @ .050'' Lift: 226° Intake / 226° Exhaust
Valve Lift w/1.5 Rockers: .470'' Intake / .470'' Exhaust
Lobe Separation Angle: 106°
Max Lift Angle: 101° ATDC Intake / 111° BTDC Exhaust
Open/Close @.050'' Cam Lift: Intake - 12° BTDC (opens) / 34° ABDC (closes)
Exhaust - 44° BBDC (opens) / 2° ATDC (closes)



thoughts ??

[Super73]

The cam they are recomending to you has 8.0 dynamic compression / 10-1 static compression. Again, heads would need to be milled 4cc's to get 8.5 DCR.

Couple other things.. It has the same amount of seat duration (286*) if they are both being meassured at ,006, however, one might be at .004.. That being said, even though the lift is higher on the 226" cam vs the 230* cam, It apears the 230* cam has faster off the seat acceleration but probably a slower rise after .200 lift.

Max lift isn't the end all thing, it's valve timing, and choosing a cam that has more duration at .050/.200 with less duration at .004/.006 is typically a good thing. It allows you to keep higher DCR with smaller lobes giving you a better idle, better bottm end TQ with out really sacraficing much up top (if any).

But, that cam would not be that great for spray. You ned to bleed down the added exhaust the N20 is going to cause. A 44* EVO point, I think will leave too much exhuast and polute the intake charge more than you want.


Let me ask you a few questions:

1) What is the max RPM you want to spin this motor?

2) any idea of the weight of the vehicle?

3) What type of intake are you running?

4) What size headers and how lang are they? What about exhaust diameter?

[ton*loc]

Originally Posted by Super73

The cam they are recomending to you has 8.0 dynamic compression / 10-1 static compression. Again, heads would need to be milled 4cc's to get 8.5 DCR.

Couple other things.. It has the same amount of seat duration (286*) if they are both being meassured at ,006, however, one might be at .004.. That being said, even though the lift is higher on the 226" cam vs the 230* cam, It apears the 230* cam has faster off the seat acceleration but probably a slower rise after .200 lift.

Max lift isn't the end all thing, it's valve timing, and choosing a cam that has more duration at .050/.200 with less duration at .004/.006 is typically a good thing. It allows you to keep higher DCR with smaller lobes giving you a better idle, better bottm end TQ with out really sacraficing much up top (if any).

But, that cam would not be that great for spray. You ned to bleed down the added exhaust the N20 is going to cause. A 44* EVO point, I think will leave too much exhuast and polute the intake charge more than you want.


Let me ask you a few questions:

1) What is the max RPM you want to spin this motor?

2) any idea of the weight of the vehicle?

3) What type of intake are you running?

4) What size headers and how lang are they? What about exhaust diameter?

well i built the motor to spin 7k. it was balanced with in .5 grams instead of the industry 2 gram standard.

truck is 3980 as of yesterday

its a professional products dual plane 1500-6500

1-5/8 headers into 2.5 exhaust with 40 series

[Super73]

I think that 226* cam they suggested will peak closer to 5,500-5,800 rpm and be dead by 6,000-6,200. Playing with your specs in Performance Trends Engine Analyzer, it peaks at 5,300 then hits a wall.

Using the same 226* lobe though on a 106icl 114 ecl (110lsa), you gain TQ starting at 3,200 rpm, you keep the same peak 5,300 but gain about 20hp and carry it much better at 6k..

Now, in Engine Analizer, the 224/230 106+4 cam I mentioned, looks exactly like the 230/230 cam you had originally thrown in the pot. But it shows a very slight gain in TQ 4,700 bellow (talking 1-2lbs) and a very slight loss of HP up top after peak (Again 1-2hp at most)

Now, the 230/236 106+4 really shines from 3,300 on up.

Bellow is what Perf Trends shows for all 4 cams. One grapgh is with out N20, the other is with a 100 hit.









I'll play with other cam profiles over the next few days and see what I can come up with..

[Super73]

This should move pretty well in your set up.

Comp Lobes:
Lobe - .050 - Lift
5069 -- 235 - .462
5071 -- 246 - .477
110icl 118 ecl (114lsa)

Heads milled / thinner gaskets to achieve 11.35 Static compression (8.5 DCR)

[ton*loc]

first off dude you rule !! thanks for all the help you have been giving.


try my cam with .500 lift

Grind Number: 282 H06
Operating Range: 2400-6200 RPM
Duration Advertised: 282° Intake / 282° Exhaust
Duration @ .050'' Lift: 226° Intake / 226° Exhaust
Valve Lift w/1.5 Rockers: .500'' Intake / .500'' Exhaust
Lobe Separation Angle: 106°
Max Lift Angle: 101° ATDC Intake / 111° BTDC Exhaust
Open/Close @.050'' Cam Lift: Intake - 12° BTDC (opens) / 34° ABDC (closes)
Exhaust - 44° BBDC (opens) / 2° ATDC (closes)


plus all this time i was avoiding getting the machine work done to the heads thinking it was going to be expensive. so i called there today and its $50. $50 freaking dollars i cant believe i've been running around trying to choose a cam around these heads and all it took was $50 i feel like a tool.

i was thinking of running my cam with 1.6 rockers to get the extra lift

or

i was thinking of the extreme xe274

uless you had another idea

[Super73]

Here you go..

You current cam with 1.5 rockers vs my suggested cam:



You current cam with a 1.5 vs a 1.6 rocker



My cam with 1.5 vs 1.6 rocker




Now, with you having the machine work done on the heads for bigger springs, what springs are you going to be using? What type of lift can they handle?

Are you going to have the heads milled as well?

What about using a different heads gasket to aid in Static compression and quench?

What is your intended use for this truck? Much cruising around? Are you worried about gas mileage?

[ton*loc]

Now, with you having the machine work done on the heads for bigger springs, what springs are you going to be using? What type of lift can they handle?

Are you going to have the heads milled as well?

What about using a different heads gasket to aid in Static compression and quench?

What is your intended use for this truck? Much cruising around? Are you worried about gas mileage?


.500 lift springs with machining to handle the same.

i think my gasket is a .39 thickness i bought them from the machine shop

um i cruz it 3-4 times a week i love my truck, and love gas mileage

[ton*loc]

should i buy a nitrous grind ? like this

http://www.compcams.com/Cam_Specs/Ca...?csid=116&sb=2

[Super73]

Well, with loving gas mileage, your going to want to keep the overlap down. Another reason for a little wider LSA.

Are you willing to order a custom Comp Cam? Looks like they can be had through Summit for $169

http://store.summitracing.com/partde...5&autoview=sku

Not sure if you trust me enough, but I think I could put a pretty nice little cam in that motor. Keep it under .500 lift (would prefer to use the 1.5 rocker).

[ton*loc]

Originally Posted by Super73

Well, with loving gas mileage, your going to want to keep the overlap down. Another reason for a little wider LSA.

Are you willing to order a custom Comp Cam? Looks like they can be had through Summit for $169

http://store.summitracing.com/partde...5&autoview=sku

Not sure if you trust me enough, but I think I could put a pretty nice little cam in that motor. Keep it under .500 lift (would prefer to use the 1.5 rocker).

i trust you dude. look at your track times you obviously know your ****, but how are we going to do it. just let me know what your thoughts are and what you come up with.

[Super73]

It's pretty simple.. I tell you the lobe numbers for both intake, exhaust, the intake centerline and the LSA. Summit/Comp does the rest

[Super73]

How does this look?

[70rs/ss]

BTW a cheap way to get your heads to accept more lift is with a set of comp cams beehive springs, they drop in with a new set of 7 degree locks and retainers and no other machine work and increase you lift ability to .550. The set-up will cost ya, about $200-250 total, and then you can take full advantage of the Vortecs flow potential of up to .500 lift. BTW, give Comp Cams, cam help a call, they can give you a couple of suggestions based on your specs, and they have a few nitrous grinds, but Dj and these other guys know there stuff too, just a second or third source for an opinion can help assure you are getting the "right" ca especially if all three are the same or close! Good luck.

[ton*loc]

Originally Posted by 70rs/ss

BTW a cheap way to get your heads to accept more lift is with a set of comp cams beehive springs, they drop in with a new set of 7 degree locks and retainers and no other machine work and increase you lift ability to .550. The set-up will cost ya, about $200-250 total, and then you can take full advantage of the Vortecs flow potential of up to .500 lift. BTW, give Comp Cams, cam help a call, they can give you a couple of suggestions based on your specs, and they have a few nitrous grinds, but Dj and these other guys know there stuff too, just a second or third source for an opinion can help assure you are getting the "right" ca especially if all three are the same or close! Good luck.

i read in hot rod magazine when they claimed those lift numbers to, but when i called comp cam they said there not claiming anything over .500

[Rodms]

If you call comp and find your grind on your cam,then get on ebay and find discountperformanceproducts in ridgeland mississippi and he will sell it to you for less than anybody his phone # is on his ads