Keoman

iTrader: (3)

Hi all,

Not sure if this is the right section for this... Wanted to make sure I've got my ducks in a row here. I am new to this and have learned from the net and some helpful friends. Suggestions are welcome.
This is a daily driven street car, just want to liven it up a bit. I guess this is kind of a "budget" build.

Build so far includes:
*906 Vortec heads
*Jegs 3/8" Screw in rocker studs
*PAC 1218 Springs
*Alex's 11/32" valve beehive retainers
*Comp 08-502-08 cam
*Comp XE 1.5 Roller rockers
*SDPC vortec TPI manifold
*Ported SLP Runners
*New Gaskets & seals
*New timing chain

This is all backed by a T56 & 3.27 gears. Have the 3.70's and will be switching after build is done. Will also be port matching new runners to IM and Plenum in the future.

Springs are rated 130lbs at 1.800" install height. OEM vortec install height is 1.700". Installing as is should increase seat pressure to around 140-150 I would estimate.

I have also looked at the Lunati Voodoo 270/278 roller cam, wasn't sure what rocker they use to give this cam its lift rating? Anyone?

Suggestions welcome!

Thanks

raynehr

I built a vortec headed nova a few years back, I did not check your cam specs, however if you get close to .500 lift on either side with vortec heads, the pushrod guide has to be extended or the pushrod could hit the head. Just takes a dremel tool or die grinder and a few minutes and legenthen where the pushrod comes through the head.

Jim85IROC

iTrader: (2)

One thing I would recommend is that you take a look at porting the base before you put it on the motor. The Vortec TPI base is known to flow very poorly and it, along with most unported runners, will be a big bottleneck in the overall airflow path.

Keoman

iTrader: (3)

Thanks for the info!!
I believe running 1.6 rockers requires ovaling out the pushrod guides also correct? My cam is rated .570/.565. Pretty good lift.

I will start into porting the base before I install it. Thanks for the tip. I'll probably end up with SLP runners, But still saving as I am purchasing in steps.

raynehr

Definitely extend those push rod guides!! You are gonna be closer to .600 lift with 1.6 rockers. What is your reasoning for running such a HOT cam and cast iron heads? I would look into an aluminum set, dissipate heat better, can use a little lower octane fuel. With so much lift, I would be a little tentative with piston clearance too. That is a lot of lift!

Keoman

iTrader: (3)

Will do on the rod guides.
Reason for the vortec's is budget. 100$ + valve job & spring seats vs 6 or 7 times that for decent alum heads.
Interesting about valve piston clearance. Out of all the people I have talked to about this build, you are the first to mention this. Anyone else?

Jim85IROC

iTrader: (2)

I didn't know about the issue with the pushrods contacting the heads with higher lift at the time, so I bolted my heads on as-is. With my ~.500 lift cam (with the 1.6 rockers), my pushrods were nowhere close to rubbing, so I'm not sure that this is an issue with all of the vortec heads, but certainly if you're going to run that kind of lift, you're going to want to bolt them on and check, or just go ahead and clearance them beforehand.

raynehr

In the Vortec Nova I built, I had a .488 lift cam with spray and they came too close for comfort for me. It may be different in different casting years, not sure. Its such an easy thing to do, mine as well knock it out. As for the lift, I personally clay engines with lift over .550. Built about a dozen hot motors in my day. I am a "Safe than Sorry" kind of guy when building.

Keoman

iTrader: (3)

I think I'll just stick to 1.5 rockers as I am not familiar with the piston/valve tolerance checking that needs done, nor do I have the tools to do so on hand. I will be able to use my 7.800" pushrods also.
1.5's will put me at .535/.531


I will take some out before hand. Not real hard to do and I would sure regret not doing it if rubbing was the case.

So I'm not mistaken, this is the area that needs enlarged.

Jim85IROC

iTrader: (2)

If I discovered it before I bolted the heads on, I would agree, but because I didn't find it until they were already on the car, I didn't want to pull them off and have to trash a set of head gaskets if I didn't have to. I rotated the motor with a checker spring in place and had ample ( >1/16") clearance, so I moved on.

Keoman

iTrader: (3)

Just stumbled on your vortec thread Jim, using a lot of the same parts!
Thanks for doing the write up and taking pictures! Lots of good info in there!!

Jim85IROC

iTrader: (2)

No problem. I'm glad it's helping somebody.

Fast355

iTrader: (2)

I would run the CC304 cam like they used in the Something New, Something OLD TPI 350 Vortec buildup that made over 400 hp and nearly 500 tq.

Keoman

iTrader: (3)

Just read through the build, they put quite a bit of work into that engine!

The 304 cam looks just slightly more aggressive than a 93' - 95' LT1 Cam. I can't pretend to want to follow their build, however. Their build is far more efficient than mine. I will need compensation from the cam to raise my numbers.

Jeremy said it well,

raynehr

I think you are on a much better "Streetable" path this way, but all in all its your call. Keep us updated on how that puppy runs!

Fast355

iTrader: (2)

I have a CC304 in a daily driven chevrolet express van. Has a S10 2,600 converter and doug thorley tri-ys but is otherwise stock.

darbysan

one other item to consider is a newer style heater control valve. These allow the water to circulate back to the radiator through the heads and intake even when the thermostat is closed. Helps to prevent overheating. Part is used on Vortec trucks. PN is Murray 74781, for a 97 C1500 p/u with 350.
http://www.oreillyauto.com/site/c/se...RWD&vi=1031555

Using this will eliminate the need to install a bypass hose from the front of the intake to the water pump. They are a pain to install!.

Keoman

iTrader: (3)

Interesting.
I'm not sure I understand why you would want this. Not for the sake of argument, but for understanding. What makes the cooling system different with vortec heads vs L98 heads? My cooling system works 100% right now in any temperature I have put it through so far. Kindof a "If it aint broke, dont fix it" thing i guess.
Is that heater control valve necessary or just "better"?

darbysan

It's a tip I got from another site, and thought I would try it ( get's hot here in Vegas!). The Vortec heads do have a different flow pattern for cooling, and utilize a port on the front of the intake to keep this flow moving when the thermostat is closed. If you have that port connected to the water pump, then you are getting the same result as the newer valve. Many don't hook up that extra port ( It's a bitch- very tight turn), and as a result the heads can get hotter than they should ( issues with cracked Vortec heads are well known). I think it is just good insurance, especially since that was the way they were designed and installed on the trucks.

Keoman

iTrader: (3)

Might not be as good as installing the bypass, but wouldnt drilling 1/16" holes in the stat flange also get rid of "hot pockets" while the stat is closed?

Juan_Garza

iTrader: (1)

sorry to step into your thread but i have a question, i got a 350 from a 99 van with 75k miles, im getting alex springs for the heads, and hsr system; my question is what cam do you recommend and what rockers, I want a street friendly car with some punch, i appreciate all imput thanx in advanced

Keoman

iTrader: (3)

I ended up getting the Comp 502 cam.
http://www.summitracing.com/parts/cca-08-502-8

BUT I am still running long tube TPI. Whereas you going to use a HSR, this cam probably wont be optimized for your setup. You can probably run a lot more aggressive camshaft. Perhaps someone with more knowledge will chime in.

Are you using Beehive or double springs? Link?
I would STRONGLY recommend installing screw in studs. Its extremely straight forward and you'd be surprised how easy the old ones come out.

Juan_Garza

iTrader: (1)

im using alex's valve spring kit, and how bout roller rockers? I dont have a clue what srew in studs are im very new to heads im just doing what alot of guys are doing here and following some of the stuff they do.

Keoman

iTrader: (3)

I used Comp 1417-16
1.5 rollers

http://www.summitracing.com/parts/cca-1417-16

EDIT
These rockers are junk. Despite great oil pressure and correct valve geometry, rocker to pushrod cup chewed its self away in a matter of hours of running the engine.
Use Comp 1617-16 full roller set.

Keoman

iTrader: (3)

Not sure why but the Machine Shop refused to pull the rocker studs out of the heads. Said they had broken all the heads they had tried. Even showed me the last set they tried.
15 minutes and an impact and I had them out no problem...

Also reamed the pushrod guides with a drill bit. Took them out 1/8" on the diameter.






Also did a little opening up on the runners. Port matched the plenum also.

Juan_Garza

iTrader: (1)

Are those direct bolt on my vortec heads?

Keoman

iTrader: (3)

Yup