Hey guys I just signed up and I'm sure I'm gonna get noob bashed and told to use the search engine but I had a few questions.

I just recently purchased an 89 formy with a 98 vortec motor and world class t5. The motor is stock aside from shorty headers and 3 inch exhaust, world products vortec intake that mimics the performer and a holley 600 vacuum secondaries. I wanted to know what would be some good mods to this motor to get the most out of it without pulling the block as in what cam should I run (I want something lopey) and what should i do to the heads (062 castings). Should I run a different intake or different carb? the rear end has a non posi 2.73s but I'm looking at running an auburn with either 373s or 410s. I'm also running a 28inch tall tire in the rear and using a holley blue fuel pump.

Any help would be greatly appreciated. A friend told me to do bowl work, change to a 1.60 exhaust valve and run a cam that he has, specs I know are its a solid lift cam with a 447 lift and 292/298 duration.

And sorry for noobing you guys

 

Leave the heads/valves alone! and from the type of questions you're asking, you have no need going to a solid roller cam. That "friend" of yours is not giving you very good advice.
If it weren't for your desire to have a lumpy sounding cam, I'd tell you to leave the motor totally alone; with the rest of the car properly done, it could run high 12's in a light 3rd Gen. If you just want lumpy, pick up a LT4 Hotcam and a set of Comp beehive springs and retainers.

 

Thanks, I told him and he said its a solid lift and not a solid roller and he said with that and the work done to the heads I would be in the 380 flywheel hp range. As far as the cam goes, I want the best performance but some lope, is that possible?

In your opinion what should be a good combo for a mid to high 12 setup for my bird?

 

Stop listening to that guy....he's clueless! If he's a friend, keep it that way and get your engine advice elsewhere. Be careful of this place too! Half of those who post with "advice" are just keyboard ****!

With lots of practice with the T5, something along the lines of a Comp 502 cam (have to stay small because of the low CR of the stock Vortec engine) and 915 or 918 beehive springs/retainers, 4.10 gears, and slicks; the combo is capable of going mid 12's. Other than the springs, don't touch those vortec heads.
If you don't already have these things, you need to do them: subframe connectors, stiff rear suspension bushings, possibly IC relocation brackets?? (I'm no expert on launching manual trans cars).

 

Thank you I really appreciate the help. http://www.compcams.com/Cam_Specs/Ca...?csid=195&sb=2
Is this the cam you are talking about?

 

Yes

 

would the thumpr cams from comp cams be a good cam with the 915 springs?
http://www.compcams.com/Cam_Specs/Ca...?csid=216&sb=0

 

That's way too much intake duration for the stock CR. The car would be a dog down low, and only begin to make power about the time the intake and carb would restrict it.
Here's an improvement upon the off the shelf 502 cam:
Comp XE lobes, 218/224/110, ICL @ 105 degrees. It will build more midrange torque than the 502 and peak a little earlier, more in line with your current intake/carb setup. It's a custom grind, but last time I got one from Comp, it was only $25 more than a shelf cam.

 

Before you decide on a cam, you have to know what your static compression ratio is. From what I've found, an " 98 vortec motor" may have a CR of 9.1:1. If you can verify that, then you can zero in on a well suited cam.
As pointed out by 86LG4Bird, the Vortec heads are fine in stock form. If you're going to go to the trouble to remove and modify the heads (which is a lot of work and expense for little gain at this power level) then you can address the CR as well.
Check my sig. You may be looking for the kind of modest performance I've managed to squeeze out of my Vortec combination.

 

thx guys, I have the professional products cyclone intake but I want to step it up to the crosswind intake that is identical to the rpm air gap and a 650 double pumper. with no added modifications, will the lt4 hotcam or that comp cam 502 and valve springs work fine? I have shorty headers and 3 inch exhaust to a dumped flowmaster, no catback. and if this setup works, what kind of power am I looking at at the flywheel?

 

Dont do any bowl work to the 062 heads, the first time I pulled apart a set I couldnt believe what a good job GM did casting these heads. If your going to run an aftermarket cam remember the max valve lift on vortec heads is .470" . You can have the guides cut down or do the ghetto retainer grind (search it) for more lift. I would say 230s duration on the exhaust side and 220s on the intake would be the max and maybe even a bit much. If your running a carb (non ecu) you can go with a closer lobe seperation to get the idle you want, something like a 110-112. Heres a clip of my car with a 224/230 ...and a 112lsa cam in it It also has alot more done than that but the tighter lsa has alot to do with the loping
<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player...A/PA200636.flv">

 

which cam is that? and if i did go with the 502 comp cam or that custom grind one or even the lt4 hotcam, would it be ok to run any of those as long as i got the springs to match? and i plan on just using 1.5 roller rockers

 

My cam is a comp 276hr12. Youll have to research the lift of any cam you want and make sure it isnt over .470. All most every time you see the lift of a cam its assuming 1.5 rocker arm ratio. You always want better springs with an aftermarket cam
Heres a deal summit is running right now, trickflow roller cam for $120 which is very cheap. I dont know much about the cam but the numbers look good for a lopey idle with stock head lift limits
http://www.summitracing.com/parts/TFS-31402000/

 

I also use the XE276HR with Vortecs. ( 110 lsa and 1.6 rockers)
However before you decide on a cam and try to calculate what kind of power you might make you have to know what your static compression ratio is. Mismatched cams are probably the number one reason for a poor performing combination.
For the record, the 276 will require either beehive springs (no machining required) or the mods necessary to install a more traditional valve spring in the Vortecs.

 

I greatly appreciate the help guys, I looked up the specs on both cams and the first looks suitable for what I have now and the second looks good if i upgrade a few parts. for that 276 cam to work, if I get the 915 beehive springs, can any machine shop easily install them with any other necessary parts?

 

You can install the behives yourself. Youll need an aircompressor, spark plug fitting and a valve spring compressor. You should also replace the valve stem seals while you have the springs off. Pull the spark plug and install the fitting into the hole( make sure you have 80psi or more), use the valve spring compressor to remove the old one, put your new seal on(oiling it will make it easier), compress the new spring with the retainer in it and put it over the valve and start decompressing it. Slide the locks into the groves once its getting close and keep unscrewing it. Once your all done give the retainer a light tap with a hammer to make sure its seated and your done. Try and find pics online of someone doing this, if you cant find any let me know and Ill try to help

 

Thx man, I would like to try it myself so I can learn. I'm going to look up pictures, if I cant find any I'll ask you if you can help. Thank you. With that cam, an air gap intake, 650 double pumper, shorty headers, 3 inch exhaust, hei ignition, do you think the flywheel horsepower will be around 300-310?

 

That would be very do able. Its all about matching parts to each other. You should end up with a really nice street motor.

 

awesome, I was reading that the vortec heads can support up to 400hp but is that with work done to the heads or just the stock heads with a good setup? I would like to be able to be a mid to low 13 sec car on street tires.

 

theyll support 400hp with a spring upgrade

 

ahh ok, along with whats been done to my motor and the cam you suggested, what else would need to be done to get to the 400hp mark? diff cam? msd?

 

With the factory 350 Vortec cam, 1.6 roller rocker, better intake, headers & 2800 stall convertor our 90 Camaro was running in the 13s on street tires. With 4.10 gears+ the other mods you should be in the mid to low 13s depending on your elevation.

 

This is the setup i was thinking minus the cam the guys were suggesting. 650 holley double pumper, rpm air gap, 1.6rr, I already have headers and exhaust, posi, 4.10s, drag radials, its 5 spd and lower control arms and subframe connectors. with that would low 13's be possible and with that 276hr cam 12's be feesible?

 

With the right cam you don't need to go with 1.6 rockers. Going from 1.5 to 1.6 rockers is like going 1 size bigger cam without actually changing the cam but you have to watch out for coil bind & the pushrods rubbing.

I'm running the XR270HR with 1.6 RR in a 383 Vortec in my 99 Suburban but I have after market alum vortec heads so I have no issues with the .534 lift. I've very happy with the cam in my Burb.

With the right driver & low elevation you should be able to run 12's.
Here's a dyno sheet from Comp Cams.
Compression:9.25:1

 

Sounds like you're trying to build a combination very similar to my own.

 

how are you doing your setup exactly skinny? and heslekrants, do you think my setup would go low 13's with the stock cam and the 1.6rr?

 

350 with flat top pistons.
Vortecs modified for screw in studs, guide plates, push rod holes enlarged to accomodate 1.6rr. Heads milled .006" to ensure they were flat. Comp cams bee hive springs. (No machining required).
XE276HR. Duration @ 0.006": 276° / 282° Duration @ 0.050": 224° / 230°
Max Lift w/ 1.6RR: .535" / .544" Lobe Separation: 110°
Lobe ID#'s: 3314 / 3315 Intake Centerline: 106°
RPM Air Gap. 670 vac sec Holley (Street Avenger)
1 5/8 LT headers.
10.1:1 static compresion ratio achieved w/ stock piston below deck height (.025"), 63cc
combustion chambers (1cc less than stock), .026" Victor Reinz head gasket.
This engine in a 3700lb IROC, 700R4 trans w/ 3000 stall converter, 3.27 rear gear, 26" treaded bias slick runs 12.7's all day at 105 mph.
I drive it to the track and manage over 20 mpg on the hiway.
I use a wide band O2 sensor to do my tuning and spent some time on the spark curve using a distributor machine as well as a dial back timing light and tach.
There's more in this package too once I sort out the muffler situation or use some exhaust cut outs and tuned collector lengths.

 

With the setup you have, stock cam + 1.6RR should put you in the low to mid 13s. Vortec heads use self aligning rockers.

I've ran 2 350 Vortecs with the 1.6 roller tip rocker and didn't have any coil bind or rubbing & they fit under my stocker valve covers. On my Suburban I ran them for over 70K miles before I replaced the motor with a built 383. Those rockers didn't show any abnormal wear nor did the pushrods even at 220K miles.

Left are 1.6 SS full roller rockers that will not fit under stock valve covers.
Right are 1.6 roller tip rockers that will fit under stock valve covers.


Here's the 383 in my Suburban. Internal balanced, all forged, 6" h beam rods, alum heads with 2.02/1.60 valves, 1.6 ssrr.

 

True.
I had to clearence the internal rocker cover brace to allow for the additional width of the Comp Pro Marnum full roller rockers.

 

Here's my solution for more rocker arm clearance.

 

Is that an adaptor I see under those nice looking valve covers?

 

No, my heads have dual bolt patterns so I can run center bolt or old school valve covers.

The design of the valve covers I have expose part of the lip of the sealing surface but they don't leak.

I did have to modify the alt & ac brackets to clear the valve covers.

 

to run 1.6rr do I have to enlarge the pushrod holes or is there a set I can buy and just put on, I'd like to not have to worry about taking the heads off to do machining just yet. and thats a sick looking motor heslekrants. lucky burban

 

Yes, you will have to enlarge the push rod holes for 1.6 rockers.
Do you intend to use a guide plate arrangement in the future? Stock Vortecs use a self guided (or rail rocker) for push rod alignment. A guide plate head cannot use this style of rocker and the more conventional non guided rocker arm must be used. To upgrade to 1.6rr now and then modify for guide plates later will require two sets of rocker arms.

http://www.chevyhiperformance.com/ho...458/index.html

Note: This article was written before the Bee Hive spring modification became popular.

 

These will fit under your stock valve covers.
http://cgi.ebay.com/ebaymotors/COMP-...item2eaa707ee4

http://cgi.ebay.com/ebaymotors/SBC-C...item19b618c961

I've read that you have to enlarge the pushrod holes to run 1.6 rockers on the Vortec heads but I didn't have any coil bind or rubbing issues on the 2 motors I installed then on. It's something you should check but these stamped roller tip rockers seam to work just fine without any grinding.

I used the cheaper rockers on both engines.
70K miles on 1 with no noticable wear.
10K miles on the other before we sold it and those were some pretty hard miles & no issues.

In both motors once I had the rockers installed I didn't have to go back to adjusts them but I did pop the valve covers just to take a look.

 

Oh ok, if I run full roller rockers than I need to enlarge the pushrod holes but with roller tip rockers I'm ok? or should I just focus on a cam swap? I do want to do a full motor build but not just yet. I just dont want to pull off the heads yet.

 

What it amounts to is with guide plates you must enlarge the push rod holes, with self guided rockers, you MIGHT have to. It's something you will have to check and verify when you trial fit the parts.
Do you have a roller block?

 

Yes the motor is roller. If I buy the full self aligning roller rockers, I might be ok?

 

I think you'd be stupid to go with a flat tappet cam, but if you do decide to do that, my xe262 setup works very well. Not the quickest car on the road, but it trapped at 102 in the 1/4 on a very awful run when I was still learning to drive a stick in a 3500 lb car (Thats with driver). Thats in the neighborhood of 300rwhp.

Go roller and you should do a lot better. I've got a pretty efficient setup though. The intake and exhaust flow very well

 

Yea I'm staying roller, that 276hr cam they suggested is roller. Id like to get the most power without pulling the heads off.

 

To run the 276 cam you'll definitely have to upgrade the springs. That cam with that lift combined with a 1.6rr (of any style) will most certainly need the pushrod holes enlarged too. You will be exceeding .530" lift. I would also suggest that using that cam or something along those lines would also require screw in studs or at the very least, pinned studs.
Maybe think about a cam that keeps the lift below the stock Vortec limit and keep the stock springs, rockers and studs. I know you can have an enjoyable low 13 second ride with the smaller cam and box stock Vortecs. Lots of inexpensive arrangements using the OEM roller setup too.

 

You're gonna have a ahrd time finding a good roller that will make a lot of power for you and stay under your .470 inch lift requirement. At .510 lift that cam is a pretty good ways out of your safe zone. You'll need some valve guide work at least.

 

Not true, the beehive springs allow much more lift with no machine work. I believe .550

 

This is true ( I did it myself ). However it's still good practice to check the installed height and actually measure retainer to guide clearence to be absolutely sure there is no interference.
My suggestion for a cam with less lift is for simplicities sake. You can slip in a small hydraulic roller with no mods. With the low static compression ratio of the OEM 350 Vortec you'll build a little more compression pressure with the shorter cam and have a combination that's more fun to drive with the improved bottom end torque.
The 276 (or larger) cam can wait for the spring, screw in stud, 1.6rr and push rod hole mods down the road. Not to mention an increase in compression ratio that's needed to better suit the increased duration of a larger cam. That is if an economical approach is what the objective is at this time.

 

Running the stock L31 350 Vortec cam with 1.6 rockers puts the lift around .450, well within the limits of a stock Vortec head.

If you are going to change the cam then pick the cam with the specs you want then stay with the 1.5 rockers.

Going with the beehive springs & more lift you will still have to check for coil bind & push rod clearance even if you are staying with the 1.5 rockers.

The 1.6 rockers is like going up 1 cam size for around $100 & only takes 1hr to swap. If you want more than that then you may want to wait & do cam & headwork at the same time .

 

http://www.summitracing.com/parts/TFS-31402000/
You guys mentioned this cam earliar in this thread, in all your opinions, should i run this cam or go with 1.6rr. I will be doing a full motor build but not right now, I dont want to pull the heads off just yet, the motor is low mileage and running well. And I thank all of you for your help and advice.

 

That cam is kind of a "cover both bases" cam. Yes, it will work without head mods (except for the springs) at this point, and yes it will work in the future if you pull the heads and get your compression up to better complement the intake duration, as skinnyz mentioned. BUT......it's not the best choice for right now, and it's not the best choice for later with head work, although would be decent with 1.6 rockers at that point.
Based on my experience running both the stock L31 cam and the ZZ4 cam (208 intake dur) with stock heads, your best bet for now is to stick with the L31 cam and put 1.6 rockers on it. With stock compression, that TrickFlow cam will give you a weaker low end all the way up to about 3000 rpm compared to the stock cam. Even with my ZZ4 cam, I've put loads of extra ignition timing in up to 2500 rpm to get back the torque loss, and you're talking about an even later IVC event with that TrickFlow cam.

However,....if you do decide you have to have it (I realize the price is tempting!), do not just install it without degreeing it; install it at a 104 ICL to get back some of the torque loss.

 

While the TFS cam won't make the most power combined with your Vortec heads it certainly would be a simple swap in that you really wouldn't have to upgrade the springs or modify for screw in studs. The shorter duration (as opposed to a 276 or larger cam) will help with torque which makes driving enjoyable.
As has been pointed out you will still have to check for coil bind (the TFS cam is getting very close to the Vortec limit).
Once you've had a little fun, you can plan the next upgrade.

 

Interesting point. I checked the cam specs at Trick Flow and they don't indicate the ICL. Yes, you definitely will want to advance the cam if the value isn't ground in.
I ran a similar flat tappet cam for a year or two with box stock Vortecs. No spring or stud mods. Managed low 13's in a 3700lb car w/ a small stall convertor and 3.7 gears.
What I'd really like to know are the internal engine specs of L31. What size piston dish? Head gasket thickness? A static compression ratio vs dynamic compression ratio calculation is in order.

 

skinny, I have to take exception to your comment about not upgrading springs to run that Trickflow cam, or ANY cam for that matter. The stock L31 springs are not even adequate for the stock cam over 5000 rpm after some mileage on them. If he's not going to rev over 5000 rpm to take advantage of the new cam, then there's no point in installing it.