5.7 Vortec Cam??

[autolover3]

I have searched and found some good information but no sure answer. I am tossing the idea of putting in a cam during engines class next semester.

What I have-99 Yukon with 5.7 vortec. Modded intake and throttle blade, blackbear tune, pacesetter longtubes, dual into single exhaust no cats or muffler (thinking of adding muffler ), egr delete, transgo shift kit, stock 3.73s, 32" tires.

I would like something that will provide most hp/tq while staying in stock convert pwerband and is very streetable since its my DD. I'm thinking of either a LT4 production cam if i could find one, or maybe ZZ4 or HT383. Or equivalent comp cam etc. Also would like to keep 1.5 rockers, but what else should I plan on buying??

Any input would be awesome!

 

[red99hoe]

comp cam...Xtreme Energy™, XR269HR

Part Number: 08-503-8

i just rebuilt the top end on my 99 tahoe. In my build, I used the 08-502-8, but there is to much lift for your factory valves. I don't have factory heads. With this cam you can keep the same tune you have. I also kept the 1.5 rockers.

I used the summit vortec heads and the 503 cam, pacesetter shorty headers flomaster mufflers and dyno tuned. Brian with pcm for less did the tune.

Stock bottom end with 140,000 miles 282 rwh 390 fp tq. I am really happy with the way it runs.

 

[autolover3]

Seems that Comp cam would be a little large than what I would like. I am keeping stock torque converter and have read on some other chevy forums the ZZ4 crate cam would fit me well. I wouldn't have to machine heads if I ran beehive springs and retainers with 1.6 rockers with the ZZ4 and can find the cam for $200 online. What exactly is the gain from switching to 1.6 rockers instead of 1.5's?

Also I would get it tuned for my cam specs since Blackbear has free retunes if I recall correctly.

Thank you for your input, greatly appreciated! How do you like your Pacesetters?

 

[red99hoe]

I think that the 08-502-8 will work with your factory heads. I am, bye know means, an expert on this. I did the same thing that you are doing. started reading forums. You need to weed through a lot of B.S.
Don't waist your money on a CAI....made know difference....
You most likely will not see a difference between longtube or shorty headers.
Unless you are running your truck above 5000 all the time, roller rockers are a waist of money.

when you you replace the cam, I would get new lifters push rods and rockers. I would replace the timing chain and the cover. It might be a good time to put a new water pump on as well

Going from 1.5 to 1.6 allows the valve to open further and stay open longer.

 

[autolover3]

That 08-502-8 seems very similar to the LT4 hot cam correct? I'm trying to keep this a budget build (also not wanting to cut corners but you get what I mean )

I don't plan on buying a CAI since I prefer GM's factory fender fed air box, I have removed the silencer box and did the throttle blade mod. I love my Pacesetter longtubes I recently put on with dual into single straight exhaust.

The timing chain and cover is on the list for sure, will see what other components look like and I just recently installed new water pump.

I think I'm at the point if I want to do either the LT4 hot cam, or the ZZ4 crate cam. Do you know would city drive ability be alright if I went with the hot cam with a stock torque converter or should I go the ZZ4 route.?

Thanks for your thoughts!

And I absolutely love reading through forums and have gained the ability to generally decifer who's blowing smoke and who isn't.

 

[SunlitComet]

CAI do make a difference in power and induction noise est about 9hp for a 57 series K&N unit.

Shorty headers often gain about 8-12 hp but tri-y units which blend 4-2-1 on each side give you good torque and hp on an average of 24hp and #'s. Long tubes will get more hp but mostly at the high end which is good for constant high speed runs. any roller type of rocker will reduce friction. At the least get roller tips. and because you are removing the timing cover you will need to do the oil pan gasket as well. They are kind of married to each other. And you must purchase a new cover as the old one can not be reinstalled. And you will likely find that even at 200k miles you can reuse your chain and sprockets. Oh and 1.6 rockers will require head modding. And keep in mind you can't go crazy with the cam. Look for the ability to work with computer controlled engines. Comp has a few that do. Leaning towards crazy cam will definitely need a basic tune just to get it running without errors and then dyno'ed to perfect it. That dyno work could easily reach $500+.

 

[autolover3]

I'm not interested in spending ~300$ for an minimal gain intake right now. Don't long tube or in general equal length long tube/runners increase torque due to air velocity? I plan on running hydraulic rollers since that's what the vortec is oem correct?

I am planning on running the ZZ4 cam, 918 springs, 787 retainers, and I think the 648 locks. Possibly 1.6 rockers, will do necessary modding of head if needed. And then let Blackbear do the rest!

 

[SunlitComet]

I usually suggest people start with intake and work your engine airflow way till you reach the tail pipe. If there are things you just are not interested in then you skip it. But go with the flow. They do increase torque a bit. But I would look for a dyno chart from the header maker. Sizing and length is important to get the most out of your engine without changing things in a negative way. If you get a dyno chart and are happy with what it can give you make sure it is based on existing computer and emissions equipment being intact. You would want it to where you have good high speed movement but still be able to climb some steep hill or get a trailer moving if needed. Yes you have hydraulic roller lifters. And for the CAI it would be a shame not to hear the induction noise change after doing all the work.

 

[autolover3]

I've already got the longtubes on and will maybe toss the idea around of a Volant system or equivalent.

Whats your opinion on the ZZ4 cam?

"(intake/exhaust) is 275/280
.050" tappet lift (intake/exhaust) is 208/221
lift with 1.5:1 rocker ratio (intake/exhaust) is 474/510.
lobe centerline is 112 degrees."

 

[red99hoe]

I'll tell you what I did. I read many different forums, called summit racing and jegs. Talked to there sales guys and asked them what they thought would be best. Three calls to summit, three different cams....called jegs twice, and again two different cams. I called comp cams twice and both guys there told me the same cam. So that was the one that i went with. So if I was you, I would call the manufacture of the cam that you are thinking about. they are going to have more knowledge about there product.
In my opinion, roller rockers are a waist of money on a daily driver. I will agree that there is less friction and they free up hp. If you were building a drag car, I would suggest them. I'm going to guess that 95% of your driving is below 3000 rpm. Also, there is a chance of failure in the roller rocker...
You don't have to drop the oil pan to get the timing chain cover off. You just need to drop the front of it down. Two bolts on both sides and it will give you enough room to slide the old one out and put the new one in.
There wasn't any difference in RWH between K&N cai, K&N filter, and oem with cotton filter...... I will let you decide on how you want to spend your money.

I guess the bottom line for me was that I wanted a "reliable" daily driver. It pulls hard off the line the power comes in good around 2100 rpms and continues to pull.
This is my opinion.....and you know what they say about opinions