Need advice for my first engine upgrade
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
I have stock vortecs on my motor with the L82 cam with the performer eps intake 750 edelbrck carb. motor is a 350 bored .60 over with 9 to1 pistons with stock rockers with a 4 speed with 3.36 gears. it ran 13.16 in the quarter with a 1.96 60 foot at 105 mph with a better take off it will be in the 12s easily. I love my vortec heads they are completely stock out of the box.
Intermediate
Joined: Nov 2011
Posts: 28
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hood clearance
I have my stock hood. Im running a 10 inch filter x 2 inches tall but im going to get a drop base with a 2 1/2 inch filter by 14. its a close fit but i havent had any problems I was worried about it after I ordered mine but the vortec intake only raised it about a 1/2 inch more than the older style performer. I reallly like the eps over the regular performer and its only 410 to $20 more. If you have 3.55 or 3.70 gears in your car you will really love these heads. My car ran 96 mph in the quarter with the stock 882s compared to 105 with vortecs and the torque is a big difference with them. I hope this helped. oh yeah I LOVE MY SIDE PIPES!! Always wanted a Stingray with sidepipes.
Intermediate
Joined: Nov 2011
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Yeah it ran the quarter in 3rd gear. my eighth mile time was 8.49 at 84. Car pulls hard after it gets off the line it bogs off the line but im happy with it its a cruiser. My wife and I ridein it every weekend.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Got all the parts for the short block from the shop Monday and got my heads and intake in the mail yesterday. I got the crank, pistons, cam, and timing chain on so far.
I have read a lot on installing the heads and intake. The torque specs and valve lash adjustment for a 383 seems to be the same as the 350 in most people's recommendations. I don't see any reason why it shouldn't be the same as a 350 on the upper but I wanted to check with you guys.
I have read a lot on installing the heads and intake. The torque specs and valve lash adjustment for a 383 seems to be the same as the 350 in most people's recommendations. I don't see any reason why it shouldn't be the same as a 350 on the upper but I wanted to check with you guys.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Sounds good. That is about the range that I have been reading. I am painting the block before I put the heads and intake on so I have some time to look around before I tighten them down.
In the meantime, I have been looking for any benefit to replacing the rockers in the valvetrain. I have a set of stock (Goodwrench 350 crate) rockers that I was told will work fine. Some suggest rollers, others say I must have self-aligning rockers, yet others have told me that unless I go with a completely different cam, lifters, and rods there is no point in trying to upgrade? I knew there was going to be some options here but I didn't realize there would be such strong opinions!
Is there any danger in using stock 350 rockers on a stock vortec valve train? How much difference in wear and adjustment frequency will there be? What performance gains can be expected (keeping in mind that I still plan to run stock exhaust, transmission, & carburetion for a while)?
In the meantime, I have been looking for any benefit to replacing the rockers in the valvetrain. I have a set of stock (Goodwrench 350 crate) rockers that I was told will work fine. Some suggest rollers, others say I must have self-aligning rockers, yet others have told me that unless I go with a completely different cam, lifters, and rods there is no point in trying to upgrade? I knew there was going to be some options here but I didn't realize there would be such strong opinions!
Is there any danger in using stock 350 rockers on a stock vortec valve train? How much difference in wear and adjustment frequency will there be? What performance gains can be expected (keeping in mind that I still plan to run stock exhaust, transmission, & carburetion for a while)?
Intermediate
Joined: Nov 2011
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ou Have to run self aligning rockers unless you put guide pltes on the heads. Any throttle body head will have these rockers. I used some i got off a friend that was off of a 92 model 350.But you have to use self aligning. Im going to put self aligning roller rockers on mine in the future because they would have put me over my budget at this time. Hope this helps
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Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
I was pretty sure of that, too. I think the guy telling me that self-aligning arms weren't necessary had someone else build his heads. Maybe they used guide plates so his didn't have them but I don't intend to put guide plates on.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Jumping back in here briefly - self-aligning rockers are required with Vortec heads. Guide plates aren't really a viable option as the stud bosses need to be machined for installation - so it's not as simple as "putting them on".
Roller-tip rockers are a good investment. The roller tip doesn't really buy much of anything, but the rockers are stiffer and have a consistent ratio, which the stock rockers really dont. But the GMPP ones will work fine, and they're cheap. A standard GEN I rocker won't work as it's not self-aligning.
All GEN I SBC heads use the same torque rating and sequence, depending on the fastner. If using ARP bolts/studs, then use their spec instead.
Roller-tip rockers are a good investment. The roller tip doesn't really buy much of anything, but the rockers are stiffer and have a consistent ratio, which the stock rockers really dont. But the GMPP ones will work fine, and they're cheap. A standard GEN I rocker won't work as it's not self-aligning.
All GEN I SBC heads use the same torque rating and sequence, depending on the fastner. If using ARP bolts/studs, then use their spec instead.
Last edited by billla; Nov 10, 2011 at 04:21 PM.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
I looked into this several months ago when I was thinking about doing a Votec head upgrade, (decided on Edelbrock E-street heads, instead) and to make it simple: The Vortec heads need the Vortec rockers (self-aligning). Here is a link to a page that explains it and shows a picture, look about 3/4 of the way down the page:
http://www.sallee-chevrolet.com/Cyli...ads/Vortec.cfm
An exerpt from the page:
Stock Vortec heads come with pressed-in 3/8-inch rocker studs and do not use guideplates. The rocker arms are guided (also called “rail” rockers) and employ a pair of guides or rails that center the rocker arm over the valve. This eliminates the need for pushrod guideplates. GM Performance Parts, Crane, and Comp offer self-aligning stamped-steel and roller-rocker arms that will bolt right on. Or, you can modify the heads to add screw-in studs and guideplates and then use conventional rocker arms, but be forewarned that this can add over $200 to the cost of the heads. Do not use guided or self-aligning rocker arms with heads that use guideplates, since this will cause pushrod bind and excessive wear. Also be aware that 1.6 rockers move the pushrod very close to the pushrod hole. Elongating the pushrod hole should be considered essential when using 1.6 rockers.
Scott
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Thanks guys. That cleared things up quite a bit. I understand the difference between s/a and non s/a rockers but have never seen the guideplates. Now I can see why it would be easier to just buy new arms.
Also, while I can understand the theoretical benefit (reduced friction) of rollers I wanted to be sure there is a performance increase. It seemed as if the roller would be another moving part to wear and possibly fail.
Mike
Also, while I can understand the theoretical benefit (reduced friction) of rollers I wanted to be sure there is a performance increase. It seemed as if the roller would be another moving part to wear and possibly fail.
Mike
Last edited by myko; Nov 10, 2011 at 10:31 PM.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
So after checking with my local resources I wasn't able to find any great deals (ie friends with a set laying around) on the roller rockers. I see that the steel s/a GM arms here http://www.jegs.com/i/GM%20Performan...0002/-1?CT=999 are not bad as far as price. I ran across a distributor part compatibility chart with only a few options for rocker roller s/a arms. All were expensive except the 1417-16 Comp Cams Magnum Roller Rocker, 1.52, Roller Tip, Self-Aligning at $170. Will these work and are they worth the $100 in this build (218/218 110* cam, stock rods and hydraulic lifters)?
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Scott
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
The benefits of a roller tip isn't really friction, as in the friction moving across the valve tip. It's a lot more about side loads on the valve stem. They're not really going to add more power, especially at this build level. Overall, it's all about strength and stiffness in the valvetrain.
It's really up to you - the GMPP stamped steel rockers are fine at this build level, the CompCams roller-tip items are worth the money...if you can afford them
It's really up to you - the GMPP stamped steel rockers are fine at this build level, the CompCams roller-tip items are worth the money...if you can afford them
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Keep in mind that valvetrain geometry (in other words, pushrod length)is much more crucial with roller tipped rockers. The roller tip has a very small area that presses down on the valvestem, and it has to be pretty close to perfect. The stock stamped rocker, in comparison, is basically a big, wide, flat paddle that slaps down on top of the valvestem, making it a little more forgiving as far as valvetrain geometry goes.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
I can afford them but there are so many other projects that I could pile the money into first. I think I will go with the steel rockers and aim at headers a little sooner. By the time I need a valve job I will hopefully be out of the "project car" phase and just adding little sums to maintain the car (yeah right).
Intermediate
Joined: Nov 2011
Posts: 28
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I can afford them but there are so many other projects that I could pile the money into first. I think I will go with the steel rockers and aim at headers a little sooner. By the time I need a valve job I will hopefully be out of the "project car" phase and just adding little sums to maintain the car (yeah right).
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
I'm just kidding!!
I'm pretty convinced that Billla is the real deal, so I'm definitely not going to argue with him about this. Pushrod checking tools are pretty inexpensive, so listen to Billla, and do it right!
Scott