Juan_Garza

iTrader: (1)

Ok so this is what I got, 98 tahoe longblock stock, vortec stealth ram, ls1 24# injectors, hooker headers and y pipe, one of the supreme members tells me to use the xr276 cam with alex's springs; the other members tells me this cam is untunable in this engine since it has low compression and the ports in the heads stall at higher valve openings. On top of it if I have a stealth ram, which is a short runner intake designed for high end at the expense of power at low RPMs. I thought this was a good setup I had can someone please help me, all help really appreciated.

abray1

Get some hypereutectic flat tops and solve it. You might could also get a thinner head gasket and mill the heads. Do a compression check and see if any cylinders are weak. You would want to fix that anyway and would be a perfect excuse for new pistons, rings, fresh rod bolts and true roller timing chain (accurate cam timing). Ask Comp how much compresssion the cam likes. I am in the cam market myself and just found a gm hyd roller off orad cam with 222 and 230@50 cam that works from 2000-6200 that I am looking at for my vert. I have to sell my afr heads since they are much too large for a street cruiser motor. I need some aluminum vortec heads or pro comps.

sofakingdom

iTrader: (1)

Compression in that motor is in the low 9s. Not "low", if not really "high" either. Let's just say, "adequate", if supporting parts are well chosen to go around it.

The XR276 is an OK choice but there are better for the application. However I think you'd be happier with the "502" grind http://www.summitracing.com/parts/cca-08-502-8 if for no other reason than that it'll be easier to tune. Maybe the "503" http://www.summitracing.com/parts/cca-08-503-8 if you feel more confident about dealing with that.

Johnny Blaze

iTrader: (15)

Don't forget those heads are going to need work to handle the higher lift of any of those cams.

Orr89RocZ

iTrader: (20)

Cam is fine. I wouldnt go bigger. I have tuned a bigger cam in low comp engine just fine and would have been an 11 sec car. There is a guy on this forum who runs the big 288hr cam in his vortec motor and runs 11.7's. low comp carb deal. Its not optimal but it works

Alittle easier to tune idle would be the 503 cam which is a 276 on a wider lsa. But you can get a 110 lsa to work fine. Alexs vortec spring kit will work good on stock heads and handle the lift with 1.5 rockers, i forget what the lift is with 1.6's. think alexs spring kit clears up to .550

Juan_Garza

iTrader: (1)

Thank you guys for the imput, so what do you think is a good compression to go with a daily driver? If the pistons look good can the heads be milled to obtain a higher compression? I always use 93 octane so thats not a problem, thanx in advance guys.

abray1

I have over 11 to 1 in my iroc but it is pushing it and there is a lot of head work and coatings involved. We were able to keep in all of the advance though (Ed Wright). I think everyone agrees that 10 to 1 or no more than 10.5 to 1 is the universal magic number. I have a lt5 vette that has over 12 to 1 compression but that is a different animal.

Orr89RocZ

iTrader: (20)

With iron heads especially vortecs i dont see a reason to go over 9.8 to 1 with most mild cams up to 220's duration. That will like pump gas and keep good dynamic compression for strong low end. Aluminum can do 11:1 with a good sized cam, mostly 10.2-10.5:1 for smaller cams but it all really depends on how much load the engine will see from type of driving, vehicle weight, engine temps, air temps etc etc

Juan_Garza

iTrader: (1)

So you think I should leave the engine as is with the stock compression of 9.4 or should I put some flat top pistons to raise the compression.

Orr89RocZ

iTrader: (20)

How fast you tryin to go? Lol i would leave it alone. You can cam it big enough to run 11's and risk blowing the internals apart so how much more power you need?

Juan_Garza

iTrader: (1)

I just want to beat older ls1's with a sbc

Orr89RocZ

iTrader: (20)

Well i would rather you consider better heads than vortecs or step up to the xr282hr. Rev it out 6200-6400 rpm and that should get you mid lower 12's in the right conditions and light car, where most ls1's are with simple bolt ons

Juan_Garza

iTrader: (1)

would it be well mannered in the street with that cam? I already got the vortec heads dont really want to spend too much on another set of heads, car hasnt even been painted yet so some money is going to that too.

Juan_Garza

iTrader: (1)

so this is what Im going with, 350 vortec, vortec stealth ram, ls1 24# injectors, hooker headers and y pipe, cc503, alex's springs, comp 1.52 rockers, how does this sound now? am I missing anything?

Orr89RocZ

iTrader: (20)

Bigger cam will be alittle rougher but all in how its tuned. The 503 will run very good tho, still a powerful fun combo. Should compete with ls1's.

Juan_Garza

iTrader: (1)

so you think what im going with is a good combo? Another member recommended me a mora tamed Lunati 20080130, wich looks good but i still like the 503 more.

Orr89RocZ

iTrader: (20)

Yes, i already said that

Jim85IROC

iTrader: (2)

That won't be a problem. The vortec motor with a HSR and the 503 cam should easily do high 12s, which is about a half second faster than most stock ls1 f bodies.

Juan_Garza

iTrader: (1)

Man I'm happy with low 13's but Ill take the high 12's
A guy is selling me these Edelbrock 60989 heads were recently decked .005, and had a valve job new seals and screw in studs, will these work much better than the vortecs or is the difference not very noticeable?

Orr89RocZ

iTrader: (20)

That part number is showing up as Etec 200's. Those are good heads. MUCH better than stock vortecs. With a good 220's cam and those heads, you'll be low 12's easily if the car is setup right for drag. It should be a good 40hp more than vortecs

NagleMac

iTrader: (1)

Those are a pretty big head, you might want to consider going with a larger ratio rocker arm to fully utilize those heads, at least 1.6's. Also you'll need to watch your compression. It says 10.2:1 with flat tops, which wont be a problem. I think you'll want a bigger cam with those heads though. These heads are'nt for a mild build like the 503 cam is for.

Juan_Garza

iTrader: (1)

Wouldnt a bigger cam be harder to tune? So if I go with these heads id probably need the flat tops right? Thanx guys youve been very helpful.

Orr89RocZ

iTrader: (20)

You dont have to go bigger. Some big head small cam combos do work very well. 503 with 1.6's will do fine. I would rather see 30lb injectors at that level tho. 24's at stock pressure start to get maxed out around 350-360 whp and that setup would be or should be up near that level. Or else run fuel pressure to 58 psi like ls1's

NagleMac

iTrader: (1)

Flat tops will work well, it'll run on pump gas without needing a bigger cam to bleed compression out. Youre right Orr, with 1.6 rockers you'll have enough cam to work with those heads. And i cant say much about tuning difficulties with bigger cams, Im a carb guy

Orr89RocZ

iTrader: (20)

Speed density just takes alot more time to fine tune the idle and driveability areas. 224-230 deg cams are not out of the question for a 355, just take your time with it. It will work. Keeping lsa around 112 or higher definately helps but you can get tighter stuff to work. Run super aujp code and disable closed loop until 1200 rpm and idle below 1200. Everything will be happy

Juan_Garza

iTrader: (1)

What do you guys think of these rockers with the alexs springs? Comp Cams#249-1417-16

NagleMac

iTrader: (1)

You'll want 1.6 rockers

Juan_Garza

iTrader: (1)

I got the 503 cam so ill be using that,1418-16 rockers stock vortec heads 3 angle valve job and a good cleaning. You guys have been very helpful I just cant say it enough, thanx for being patient with me.

Juan_Garza

iTrader: (1)

You guys thing I should get the pushrods or the stock ones are good enough?

Orr89RocZ

iTrader: (20)

Measure push rod length, and buy good aftermarket ones with .080" wall thickness. 5/16" diameter should be plenty

Juan_Garza

iTrader: (1)

a guy is selling me these 7608-16 Magnum pushrods for 30, you think theyre a good choice?

NagleMac

iTrader: (1)

All depends if theyre the length you need. Pushrod length is a critical number and if theyre used, you shouldnt buy them. A slight bent or warp in them could destroy your engine.

RyanJB

Don't skip out on your valvetrain components, I learned this the hard way. Get a good set of rockers, guide plates, and hardened pushrods so you don't end up binding a spring, bending a pushrod, breaking one valve, and dropping another like I did 5000 miles after your build was finished. Spending the little bit extra will save you a lot later when something possibly fails.

Juan_Garza

iTrader: (1)

ok guys ordered new pushrods, now I know I will be needing a torque converter what do you guys think of this one? http://www.monstertransmission.com/4...up_p_5036.html

Juan_Garza

iTrader: (1)

Any thoughts?

Orr89RocZ

iTrader: (20)

Not bad for the street, could use more stall for street/strip tho

MassD

iTrader: (1)

Check out jegs or summit brand converters more often than not they are b&m or hughes rebranded as jegs or summit. The jegs xhd converter is in my street strip car 3500-3800 stall and it holds up to plenty of abuse.

Juan_Garza

iTrader: (1)

I need a street car with good power I dont want too much stall, my car is stock except for the 3.73s and a 350 vortec stealth rammed wit a cc503 cam. What would be a good all around converter?

Orr89RocZ

iTrader: (20)

3200 then. I daily drive 3200 in my ls1

bestracing

Don't guess at selecting a converter, contact a good converter company like Hughes, Coan, TCI, B&M and get their recommendations for a good converter for YOUR application. There's more to it than just saying I want a 3K stall and buying one off the shelf if you want the best for what you got.

DeltaElite121

don't buy a cheap converter.. I wish I still had the extra money in my pocket from buying the HUGHES converter that I did before stepping up to something good. Massive difference in quality.

Your torque converter is one of the most important and overlooked parts on the whole car. Save your cash and buy a NICE one the first time so you're not spending your money three times over and wasting it. There's a whole lot more to it than just the stall speed, and a good converter will make a huge difference at the track (and the street).

I personally would never recommend anything less than a 3000 stalled converter.. even in a "mild" build.

By nice I mean YANK, Circle D, Precision Industries, etc.

Juan_Garza

iTrader: (1)

Thanx guys.

1gary

My signature applies to the whole build.................

skinny z

Do you yourself a huge favour and follow that advice. You run the risk of destroying your valve guides in very short order if the push rods are too short or too long.
Trust me. I've been there.

Juan_Garza

iTrader: (1)

http://m.ebay.com/itm/321235874511 you think these are good springs for my vortec heads? I got the 503 cam and 1.6 comp roller rockers.