Thinking about Vortec heads...

[Kwik_Cutty88]

What was the number of the thumper cam you used. I did one for a guy with the same set up only I used the stock factory pistons and used a .015 head gasket to get 9.5-1 and I used the smallest thumper cam. I do have the next one up the 601, mite put that one in one of the stroker motors I have for sale.

Mine is the smallest full roller one. The 600 grind. .513 intake, .497 exhaust. It's been a decent cam. When we first put the motor together I didn't really know a whole lot and really was looking for a decent choppy idle. The first motor the cam was in was a dog. Then when we built the second motor, upped the compression and put on vortec heads it woke right up. The intake operating range is matched to the cam as well, and I think that does a lot for my motor. It has torque right off idle, and it's been up to 6500 and never stops pulling. Eventually I'll swap cams for something a little more power oriented, but I really can't complain with the way this one performs.

 

[Yav8]

6500 on the top end and its still pulling. You must have some good valve springs. Thanks

 

[bigfella]

Wanna know about vortec heads ? Click the link start at the beginning and start reading ... this helped me understand vortec heads
http://www.nastyz28.com/forum/showthread.php?t=56505

 

[oldtinsmith]

From the MonteCarloSS site:
http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=1035159#Post1035159

Doug

 

[Kwik_Cutty88]

6500 on the top end and its still pulling. You must have some good valve springs. Thanks

They are comp cams beehive valve springs. Like I said I've been very impressed with this motor. Anything you read online will say you can't use a domed piston with a vortec head. But you can, depends on the size of the dome, and you must do lots and lots of measuring.

 

[81_El_Homewrecker]

I've had very good luck with summits vortec heads. $650 for a set assembled! I changed out the springs to some Isky 235D springs with an open seat pressure of about 330 I think, and everything has been great with a comp Xtreme Energy 274 roller. I also added some lighter weight retainers to help remove some weight from the valve train. I've had it wound up pretty high and its stayed together haha.

 

[pontiacgp]

Mine is the smallest full roller one. The 600 grind. .513 intake, .497 exhaust. It's been a decent cam. When we first put the motor together I didn't really know a whole lot and really was looking for a decent choppy idle. The first motor the cam was in was a dog. Then when we built the second motor, upped the compression and put on vortec heads it woke right up. The intake operating range is matched to the cam as well, and I think that does a lot for my motor. It has torque right off idle, and it's been up to 6500 and never stops pulling. Eventually I'll swap cams for something a little more power oriented, but I really can't complain with the way this one performs.

you need to contact Comp Cams cause their chart is way off. I've seen 602 crates with beehive springs consistently drop a valve at 6,4000 rpm. They thought a cheater 6,200 chip would give them the advantage

 

[Kwik_Cutty88]

you need to contact Comp Cams cause their chart is way off. I've seen 602 crates with beehive springs consistently drop a valve at 6,4000 rpm. They thought a cheater 6,200 chip would give them the advantage

I just went by what the cam card said as far as operating range. We contacted Comp when building the first motor and they recommended those springs. They have over 20,000 miles on them between the 2 motors and I have never had a problem with them.

 

[pontiacgp]

I just went by what the cam card said as far as operating range. We contacted Comp when building the first motor and they recommended those springs. They have over 20,000 miles on them between the 2 motors and I have never had a problem with them.

you posted at 6,500 rpm it still pulling so please explain how your set up is still pulling at 6,500 while by the chart you have reached top torque and hp well before that rpm. And if it still pulling at 6,500 when does your power start dropping off? On all our 602 crates it was obvious the power dropped after 5,800 rpm. Most tracks in the US have the 602 chipped for 5,800. We had a built engine that could rev 8,000 all day long but the heads had alot more than valve springs to maintain that rpm. There was about $8,000 in head and valve train work on that engine

 

[Dayzedandkonfuzed]

I think saying vortec heads are only good for .430" lift is being a little conservative. I read that they were good from .460-.490 depending on the casting. I personally ran them un-modified for a while with .480" lift with no issues, but when I took the heads in to upgrade the valves, I had the machine shop cut the seat down just to be safe.