Opinions on GM cam

[Brad]

ZZ4 crate cam Part# 10185071
I .208/ E .221 I .474/ E .510 112

I'm wondering how this would work with Vortec heads, 600cfm carb, stock roller 350 rebuild? I will eventually have a 700r4/3.73 combo and it'll be used as a dd. I know it'll work just fine, but I'm wondering the pros and cons of this cam over say, the CompCams 264 roller cam?

[G-Ring]

I bought one a while back off ebay to use in my 383, got it for $50 and it was a new take out. I then bought a ram jet cam to match the limits of the vortec heads (.474) and to keep it more streetable than the zz4. What are the specs on the 264 comp cam?

[Brad]

XR264HR I .212 E .218 Dur I .264 E .270 Lift I .487 E .495
X4260HR I .210 E .214 Dur I .260 E .264 Lift I .470 E .470
These would cost me about $220 new, but the ZZ4 cam is local on CL new in box for $150

[Ticker]

Stock GMPP Vortec heads are lift-limited to .475 so it won't work with stock Vortecs.There are spring upgrades that can be done to increase lift, but the heads top out flow around .475 so anything beyond that doesn't really add power.

There's no comparison to a roller cam - a roller will make more HP/TQ throughout the RPM range and significantly more in the midrange. Retrofit roller kits are expen$ive, adding about a $600 premium to the price of the cam. Generally I'd say that given the capabilities of the Vortec, I would not personally spend the money for a retrofit roller cam as you can't really take full advantage of the cam ramp.

Depending the RPM range you want to make power, any of the CompCams Xtreme 4x4 cams with < .475 lift (such as grind # 12-235-2) will serve you well.

[cableguy0]

150 bucks for the zz4 cam is a bit steep. they are constantly for sale for 100 bucks or less. they are taken out of engines constantly. As ticker said its too much cam for stock vortecs.

[Brad]

Originally Posted by Ticker

Stock GMPP Vortec heads are lift-limited to .475 so it won't work with stock Vortecs.There are spring upgrades that can be done to increase lift, but the heads top out flow around .475 so anything beyond that doesn't really add power.

There's no comparison to a roller cam - a roller will make more HP/TQ throughout the RPM range and significantly more in the midrange. Retrofit roller kits are expen$ive, adding about a $600 premium to the price of the cam. Generally I'd say that given the capabilities of the Vortec, I would not personally spend the money for a retrofit roller cam as you can't really take full advantage of the cam ramp.

Depending the RPM range you want to make power, any of the CompCams Xtreme 4x4 cams with < .475 lift (such as grind # 12-235-2) will serve you well.

This is in a roller block. Also, I'm planning on doing the beehive spring upgrade.

[Brad]

Originally Posted by cableguy0

150 bucks for the zz4 cam is a bit steep. they are constantly for sale for 100 bucks or less. they are taken out of engines constantly. As ticker said its too much cam for stock vortecs.

Where do you find these at $100?

[G-Ring]

Here's an old post with the ram jet/ht383 cam specs. Works good with 1.6:1 rockers too
http://67-72chevytrucks.com/vboard/s...d.php?t=255659

[Brad]

Different cam, but good link. Gonna go to Ebay and check out prices there to see if I can get it cheaper.

[Ticker]

Originally Posted by Brad

This is in a roller block. Also, I'm planning on doing the beehive spring upgrade.

Cool; I'd definitely go roller then. I don't understand the decision to do the spring upgrade, because the heads won't flow past .475...why spend money to lift a valve higher when there's no power to be had from it?

[G-Ring]

Originally Posted by Brad

Different cam, but good link. Gonna go to Ebay and check out prices there to see if I can get it cheaper.

Yeah its different but a compromise over the ZZ4. I had the same dilema but decided to put that cam in my 88 vette motor which is ironically a ZZ4 minus cam/TPI.
The point I'm getting at is the ramjet 350 with vortec heads puts out roughly the same power as the ZZ4 with L98 heads. Like Ticker said the ZZ4 lift is out of the useful range of the vortecs. So if you want to keep the vortecs, stick with a cam that utilizes their flow characteristics.

[Brad]

I guess I'd like to duplicate the hp & tq numbers from these two builds and looking for a roller cam that will do that for me:
http://www.superchevy.com/tech/0312s...ock/index.html
http://www.popularhotrodding.com/eng...ine/index.html See test's #14-17

Perhaps a cam like the CompCams XR252HR would be better:
Dur@.050 .200/.206 Dur seat to seat .252/.258 Lift .472/.480
or
X4258 looks like a good cam
Dur@.050 .206/.210 Dur seat to seat .258/.262 Lift .460/.460

[hotrod 80]

If your going beehive springs anyway the extra lift won't hurt a thing . Lift is free and doesn't hurt drivablity . Duration and centerline have direct effects in driveability . You are in the right range with the cams . I built a very similar motor , 880 vortec block , l31 heads , forged flatops . 9.8 to1 , Hydraulic roller , 670 street avenger ( he didn't like the 600 edelbrock ) for a guy with a 57' chevy . The car had 3.70 9" 700r4 . Hotcam was to much for him . We tore it down and went ZZ4 . He loved it , just enough . This was a pleasure car for him . Me personnally , I like the big cams for a pleasure car , but a DD they get on my nerves . I would go ZZ4 or smaller depending on what you can put up with . This is for you to decide

For me lope is something that i have to tolerate to make the kind of power i want . It is out of neccesity not desire . I prefer a smooth idle , but to make alot of power you sometimes have to comprimise . 308Hp and 395 tq is no slouch in the danger mouse . That is useable street power . Test 7 & is impressive also , that's similar cam specs . All depends on what you can live with lope wise .

[Ticker]

It doesn't hurt anything, but it also doesn't deliver anything.

Lift isn't "free", and lifting further than what the heads can deliver will have a negative impact on power. Higher lift means the ramp of the cam has to be more agressive, among other things.

'nuff said; I know they sell a bunch of these uprated Vortecs and people change springs...but it delivers (less than) zero power. I'll stop bearing the dead horse and just <unsub>

[Winola73]

A 350 with Vortec heads and the '395 roller cam is a great combo, makes excellent torque with a very broad and flat torque curve and puts out decent HP, it will idle like a sewing machine but pull strong to 5500. You can get new crate motor takeouts on eBay for $70 all day long. It was used in 305 and 350 Mercruisers, 350 Ramjets and HT383's. I'm using one in the 355 I'm building for my '66 C10 with a 5 speed and 3.73 gears.

[hotrod 80]

Fell free to not run from a disscussion that might help Brad make a good choice of cams for his truck.

[70rs/ss]

Brad the ZZ4 can and will work with the spring upgrade, and honestly the stock Vortec springs need to be upgraded so the, "no gain above .475" isn't the whole story." Vortecs flow into the .500 lift range, just not a ton, but definately no loss between .475 and .500 lift. That being said I too bought the HT383 cam on ebay, it was like $80 and is the factory roller type cam, and it'll be close to the Vortec stock lift limit, so the spring upgrade is still needed (for performance, as well as to get the additional clearance you'll need). The HT383 cam, Vortecs w/beehives and a nice 600-650cfm carb w/edelbrock perf rpm intake, and it should throw down some nice tq and hp numbers and a BIG smile too!!

[hotrod 80]

Originally Posted by 70rs/ss

Brad the ZZ4 can and will work with the spring upgrade, and honestly the stock Vortec springs need to be upgraded so the, "no gain above .475" isn't the whole story." Vortecs flow into the .500 lift range, just not a ton, but definately no loss between .475 and .500 lift. That being said I too bought the HT383 cam on ebay, it was like $80 and is the factory roller type cam, and it'll be close to the Vortec stock lift limit, so the spring upgrade is still needed (for performance, as well as to get the additional clearance you'll need). The HT383 cam, Vortecs w/beehives and a nice 600-650cfm carb w/edelbrock perf rpm intake, and it should throw down some nice tq and hp numbers and a BIG smile too!!

Well said .

[Brad]

No Ticker, I haven't made up my mind. That's why I'm posting up other cam possibilities for the heads I already have. I just want it all- torquey, high hp on both the street and highway. I want good torque down low for the street, yet still be able to scream by folks on the highway if needed. I appreciate yours and everyone elses opinions. I guess I'll add that I'd prefer a cheaper cam like one of these take-outs that I'm discovering, instead of the $230 CompCams since I'm on a budget....

[Ticker]

Originally Posted by Brad

It would be great if you'd give me your opinion of what would be the best cam for my needs instead of just telling me what won't work.

My apologies, I didn't think that's what I was doing. You asked for opinions about about specific cams, and I gave my recommendations regarding those specific cams. I didn't see a general request of "what cam should I use."

I thought I was trying to help, but I guess since the impression I'm giving is just so negative I should have just never responded. I'm sorry.

My recommendation would be staying within the lift limits of the stock GMPP Vortecs and selecting one of the Xtreme 4x4 CompCams such as P/N 08-409-8 or 08-411-8. I realize this doesn't fit your budget; I don't typically work with take-out cams as their condition is unknown, and the cost of failure is high.

Good luck with your build!

[Brad]

Again, I appreciate your help. Some new things to consider. I've spent alot of time researching and trying to pick that 'perfect' cam only to come back full circle and be as unsure as ever. I'll look up those cam grinds

[Ticker]

Originally Posted by Brad

Again, I appreciate your help. Some new things to consider. I've spent alot of time researching and trying to pick that 'perfect' cam only to come back full circle and be as unsure as ever. I'll look up those cam grinds

That's the way it tends to go; lots of variables to consider for sure.

Cam selection ultimately is a trade-off of a lot of factors, low-end torque, high-end HP, driveability and "sound". But the key point to consider is that some of the basic criteria are what the head can deliver, as we *must* match the cam to the head for the best power, and where in the RPM range you want to make power. If you start with those, the choices will narrow quite a bit.

To have it all, you'll need a VVT LS series

[Captainfab]

I've been happy with the performance of the Ram Jet 350/HT383 cam mentioned above, installed in a 355 with 1.5 rockers. When installed in the HT383 Gm used 1.5 rockers and 1.6's in the Ram Jet. I believe you could get away with running that cam with 1.6 rockers and stock Vortec heads. Although checking clearances is always a good idea. These cams can typically be found on ebay as 'new' take outs for reasonable cost.

[nomrlz]

i agree that there is no reaso to go much over 475 lift with unported vortecs. i've quit calling comps tech line all together. i don't know if they just push cams they have a surplus of or what but every time i call. they recommend cams that are about 2-3 levels over what the engine should get.