Right now I have a stock internal 5.3 blown with the Radix blower. I have bought a set of used 5.3 heads which I plan on having ported/polished and port matched on the exhaust side with new valves, springs, SLP rockers, the whole works. When I did this I was planning on a cam install too, and move to roller lifters. I want something that is gonna have a little bit of a rough idle and be pretty strong through out and pull up to 6000. I think I'm asking alot out of the cam.

I got to thinking about it and was thinking should I replace the crank and rods to more cubes out of it? If I was going to do that I would get new pistons as well. I want to keep the blower, so keep that in mind. I wouldn't mind buying a new engine alltogether and starting with that so I can keep driving it around while I am building the new engine.

I was thinking of picking up a 6.0 or something similar off of ebay, have it cleaned at the machine shop and start with that. It seems as though I heard somewhere that an aluminum block would not be good for my application since it's forced induction. Someone please correct me if I'm wrong, cause then I might consider an LS1 or something like that. I also thought about maybe a 5.3 with a new crank and rods.

What cam cam do you think I should use for just redoing the valvetrain in my current engine? What if I end up doing the whole thing over and building a new engine.

Thanks for any advice/suggestions in advance.

 

What is the stock compression of a 5.3?

 

I think it's like 9.4:1 or so.

 

Either a 6.0L(it's an iron block) or a LS1 would be fine. I don't think anyone has broke an aluminum block yet just from power. There is at least one out there(Agostino Racing Engine) that is holding up to well over 1000hp so block strength is not an issue. The nice thing about the LS1 is that it's 80+lbs. lighter than the 6.0L.

Comp Cam sells a cam that would be great for your truck with the blower. It's a 212/218 .522/.529 114. I imagine with a 6.0 or a LS1 it would idle real nice and pick up a decent amount of power with the blower. I'm no cam expert though.

Don't worry about the extra cubes with a stroker crank. That's what the blowers on there for.

John

 

I think it's 9.5:1.

I was thinking more cubes just for the heck of it more less. There is no replacement for displacement. I was thinking maybe a 6.0 or LS1 bottom end, maybe even forged and bump the blower up to about 10-12psi. I am thinking as a cost issue to just go with the cam and heads for now though.

 

Yeah, you could just do the heads and cam for now. Then build a bottom end and when you're ready to put it in have the heads opened up to fit on a bigger bore if you do the 6.0L or LS1 setup.

If you do a new motor get it to around 9:1. I think 10psi and a nice tune would be very safe on pump gas.

If you get a stroker crank don't put it in the 5.3L block. Get a 6.0L block or the LS1 block at least.

 

I have a friend who pulls his stock engines out and then he does an entirely new motor.

All things being equal you could start out with a complete 6.0 longblock and build that up, or an LS1 motor.

A 5.3 would be my last choice because of the small bore of the motor.

if you want to shift it at 6000 you won't want a cam with too much LSA. I think that's too low to shift and not compromise the performance of the built motor.

 

Another concern is I don't want to over-cam my converter. At 750, I don't want to step up to the TT3000 and get even worse gas mileage. My TT2600 will stall at 2300, so I don't want to go much over 2500-2800 on the powerband. Also, I cruise at about 2250 @ 70 and 2400 @ 80. I would like to go with 4.10's over the 3.73's but again .. cost may come into play there for a little while.

I wouldn't mind going higher on the shifting, but I would have to come up with a stock looking tach that reads more than 6k. The only thing that remotely gives away performance on my truck is the dual pod full pillar, and the pillar on the wheel if you look close enough. I kinda wanted to keep it that way.

 

PSJ - The Radix is a twin screw compressor. It makes full boost very quickly unlike most centrifugal setups so there is no need to run alot of rpm with it. IMO It's good for lots of down low torque.

I think that cam would be nice in a 6.0L or 5.7L. I don't think it would need to be shifted high at all even with the 114lsa. The duration is relatively low which should help keep the powerband lower.

With a heads/cam/6.0L/and 10psi I bet your TT2600 would stall a bit higher than before. I'd leave it alone if you don't want to go any higher. It'll be fine.

I was wondering something though. From your post I gather that you want a powerful but, reliable vehicle and aren't looking to squeek out EVERY last available horsepower by making the truck less driveable. Is that a pretty good guess? That's what I'm basing my comments on.

 

You pretty much hit the nail on the head with that assumption. I want a really nice daily driver that is nothing short of a blast to drive, but yet a hellacious sleeper all wrapped in one truck. I know ... it's a lot to ask for, but man what a treat it will be. I got the truck the last week of March in 2002, as of now (June 10, 2003) I have almost 30k miles on it. I absolutely love to drive it around. It's a blast to drive right now.

I was looking on eBay and I saw a guy that was offerinig a 6.0 from a Caddy and claimed that it was an aluminum block. Is this true .. ? I may consider getting the escalade engine if it is aluminum for weight savings in the tank of a 4x4 that I have.

BTW .. the Radix is a roots, not a twin screw. That's the Whipple.

I saw that there is a GP going on for Yella Terra rockers ... Are they a good rocker? I was goingto nab the 1.85's for my new heads if it would be worth it.

 

Right now there are no aluminum 6.0L blocks in anything. GM is going to make them though eventually. The LS1/LS6 block is the only aluminum block being made right now. Maybe the guy meant it had aluminum heads?

You got me on the roots deal. I'm not sure why they don't call it a twin screw though. It's made just like one.

Everyone seems to like the YT rockers. I don't have any experience with them myself though.

I think a nice stock displacement LS1 with heads and cam would rock with the Radix sitting up top. You'll only give up .3L over the 6.0 and lose 80+lbs of the nose of the truck.

 

OK, does anyone have the LS6 hollow valve part numbers? What about the Corvette valves? I was looking at the Z06 springs, what do ya'll think about that? I think I am going to go with Yella Terra 1.85 rockers too.

 

Try searching through our GM sponsor's website:

www.sdpc2000.com

I have 1.7 Y/T rockers.

Your best bet it is to figure out which combo you like the most and ask us for part reccomendation based on your block selection.

I'd do an aluminum 5.7 block since a 80 weight reduction would be very noticeable.

 

John -

quick question I want to go the FI route....and am getting ready I want to use the stock crank, 6.125eagle h beam rods and blower dish pistons.......and some stage II heads that flow about 298cfm intake and not to sure about exhaust but Ithey do flow well...........now I want either the ati with the tuner kit or the vortech first question is which is better...then how does the above set up look to you also only other question is the cam ? I was thinking 224/228 114lsa what do you think I guess with a lift of lets say like 578 or so what do you think ....currently have long tubes....ls6 intake.....the stage two heads and am going to have the motor rebuilt as stated above......I believe that cam is no more choppy then like a hot cam.....the hot cam was choppy as hell .....but produced very little power......any suggestions? or comment on the hypothetical set up I have

thanks

ERic

 

I spoke with Comp Cams today .. Here's what they recommended:

Cam: 212/218 .568/.575 114 on a hydraulic roller lifter.

This is using the 5.3L block, port/polished heads and 1.85 rockers. He told me that the z06 springs would not be enough for that because I would be getting to much velocity on the lift with the bigger rockers. They told me that leaving the valve size the same, it would start pulling hard at about 1200 all the way to 6200.

This sounds like something I would want. Something that would pull hard down low, and wind on out. Could I get away with using the stock valves, since those ls6 valves are about 340 on gmpartsdirect.com? I was also told that steel retainers would be OK to use with this setup.

They also told me that it would be a choppy cam at idle with boost, but with no boost at idle it would be a very noticable idle. Given the cam specs do you think I would be fighting misfire codes, and other problems? How much tuning would it take to get this cam running good after the heads and all?

 

Eric, that 224/228//114 is not that choppy I have heard it before and it sounds like to a B1 to me.

Eric, I have seen nice numbers from both blower, but I have a YS trim from Vortech and I am fan of Vortech since their stuff is 8 rib. Kit is klunkier though.

Flyer, I don't think that cam will lope a lot, but the combo should work pretty good.