What would you guys recommend for a vortec build? i wanna keep the heads (of course!!) the block and the hydro roller lifters this is what I'm planning but Ive never tinkered with a vortec before so help me out. I already know it comes stock with 255hp and 320trq and with a few bolt ons is capable of beyond 400hp. This build will be over the spring/summer/winter and spring 09 so budget is not a problem this will be a street and sometimes strip car so i don't want to go too outragous.


-holley carb (700cfm?)
-edelbrock non rpm performer vortec intake mani (?)
-mild port/polish work
-XE268H comp cams (flat tappet, will this work? I heard it will)
-1.6 stamped steel roller tip rockers
-new valve springs
-dougs try-y headers
-single 3" exhuast? dumping infront of rear axle (I dont care about resonation)
-pro billet MSD dist
-MSD super conductors 8.5mm
-MSD 6al
-electric fans
-edelbrock water pump
-KB pistons (10:1 compression)


I'm planning on hooking this up to a muncie/super 10 4spd and 3.73 locker. As I siad I dont know much about the vortecs but i know they are great engines. Are vortecs aluminum? any suggestions or input would be awsome.

 

how much power you trying to make?

everything looks good but i'd look into a rpm manifold. my buddy ran that intake on his mild cammed Vortec headed small block and it turned gooood times.

A 750 double pumper would work good with that combo.

I dont know anything about those headers, but if they compare to hooker 2055 shorties, you should be fine. naturally longtube would be best, but shorties will work with that combo. 3inch single exhaust will be good enough with a good muffler like the Ultraflo from dynomax or a straight thru magnaflow or any of the chambered tube type mufflers.

You already have hydraulic roller lifters in that motor, so keep a roller cam. Dont go flat tappet. My buddy made around 360hp on motor with a factory LT1 cam, vortec heads, about 9.7 to 1 compression or so, and performer RPM.

Any bigger cam like a hotcam or any cam near 220 duration will make 400 hp on that motor.

 

Stock Vortec heads are severely lift limited, and the stock valve springs are junk. The XE268 will be marginal for lift, with 1.6 rockers you'll surely have problems. The heads need to be modified by cutting the valve guides and new aftermarket springs installed.

Ditto the roller lifter cam and RPM intake manifold.

 

Thanks! Would i need new valve springs with a 220 duration cam? this is a 95% street and 5% strip car so i want all the low end-mid range torque i can get and ill sacrifice top end for it.

 

Would I need to cut the valve guides if i used a hotcam? also what springs would you suggest?

 

Comp suggested the X4270HR for mild street performance..

This is what they say I need..

-machine work to heads
-valve spring oil sheild?
-stock springs cannot be used

These are the specs..

220/224 @ 0.050, 0.474"/0.474", 111 LSA

I can get the machine work done.. and Get whatever springs I need. Would the 1.6's work with this? this stick is good from 1500rpm to 5500rpm and they say i could see 454hp at 5500rpm and 476trq at 4500 rpm. What do you guys think?
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BTW this is with 9.5CR (stock?) and mild port/polish work..

 

i'm not sure you'll see that power but does seem like a good grind. Pretty tight on the exhaust duration split, so make sure you run a good exhaust. 111 lsa looks good. Since your doing a carb i'd like it alittle tighter.

i believe that lift is with 1.5 rockers so with 1.6's your lift will be up around .505". too much for stock vortecs. You need them machined up to clear that lift. OR you can get Beehive springs/retainers etc for around 200 bucks.. very good spring and the design allows for near .550 lift i've been told from members on this site. No other machining required

Another thing is shimming up the springs .045-.060" and running positive offset .050" locks. This raises the spring assembly .050" above the guide boss so you can get near .050" of more lift. Doing that should clear that cam with 1.6 rockers but it will be very close.

 

Ya I wasn't too sure about the 454hp. So if I use that cam and get 1.5 rockers i should be in the clear and only need the beehives? All the other cams they suggested were up too high in the rpm range like 2,000-8,000 so i chose that one, it was #3 on their list.

Are you saying NOT to use the roller cam and RPM?

 

he is saying use those things. i'd keep a roller lifter and roller cam

i believe you could run 1.6 rockers and use that cam if you run beehive springs. BUT i'd search on that to be sure.

 

Ok, thanks guys!

 

Is that supposed to be XR270HR?

Right, I meant the roller cam and RPM intake were good things to use.

Keep port work to a minimum, concentrating on clean-up and smoothing, not changing the shape or size of the flow path. Conventional wisdom is you're more likely to hurt flow than help it if you don't know exactly what Vortecs need.

You might consider 1.6 on the exhaust and 1.5 on the intake.

I just got a set of beehives for the 396. The valves were floating well before the top end of the cam powerband, even with Comp recommended springs. Called their help line, they admitted the recommended springs were marginal with my cam. So, I said "What about beehives?", and they gave me the p/n's for springs & retainers that would handle the cam. Hope to get them installed soon.

 

No they had the XR270HR as #1 on the list though, The X4270HR was #3.

I thought about doing that also..

 

Is this going to be your daily driver vehicle in to work? If not, i'd cam it up. A small cam kinda gets boring actually. You have the gears to go bigger already.
The XR276HR is a good one, that's 224/230 IIRC.

The X4270HR cam is a 4x4 roller cam. http://store.summitracing.com/partde...8&autoview=sku
Not a bad cam, but a very narrow split on the duration. I suppose that would tend to work well to promote low end power. I think that's an OK plan - however vortec heads are notoriously weak on the exhaust, so i'd want a LONGER spread on the exhaust actually. Or the 1.6 rockers on the exhaust.

That's a very good idea.

It's really a matter of opinion. I'd go to a bigger hydraulic roller, in an FI style. This would have wider LSA, to tame the idle, make it easier to tune for (tune the carb i'm talking here) - yet give you a WIDE powerband, vs a shorter LSA. This would make it idle well, and have good top end power.

If you're not planning on getting this new vortec setup done in the near future, you'll have to check out my cammed up 350 http://store.summitracing.com/partde...5&autoview=sku
As Tim Taylor says - rahhhrahhhhrahhhh!

 

No, I got a truck for work I'm just driving the car for now, But I will drive it alot..

Wow i didnt even see that



Thanks for the advice guys! Its going to be a year long build I don't got the budget to do a full out rebuild all at once. Are you talking about the engine in your car jay? I'll have to come check that thing out sometime for sure it sounds bad *ss. What cam are you running?

 

Yea, well the engine sitting in my garage, which will be going back into my car. Third times a charm right?

The cam I linked to above is the cam i'm using. Isky solid flat, 240/240 108LSA. It's going to sound.... Very lumpy. Ear to ear grin type of thing. It should be running this spring sometime.