Since you mentioned changing to aluminum heads (post #146), I'll post up my combo (see sig). Making good power at the wheels, but so far track times have been disappointing (13.01 / 105; did 12.91 / 106 with Comp 268XFI cam...). I'm hoping the swap from the listed converter to a Yank SS4000 will help the ET & MPH in the 1/4 mile.

Bill

P.S.: Cylinder heads are part# 1034, milled to get 62cc combustion chambers, installed with stock replacement GM head gaskets.

 

Happy dyno?? those numbers rival my old 383 for hp, i'd expect mid 11's out of that combo

 

I don't see any reason to question the dyno, those numbers were / are on par with normal output being reported by other cars on the same day / dyno. I've seen plenty of 350 / 355 / 383 dyno numbers that don't match the reported output of my car. Another car that posted 388rwhp on the same dyno trapped 110 mph.

I posted to show the OP an example of an engine combo that met expectations.

Bill

 

Bill, did you make that 12.9 pass on the 268 cam? This cam? http://www.jegs.com/i/Comp-Cams/249/...oductId=757952

 

Yes. Made 387rwhp / 377rwtq, as reported by the "Happy Dyno."

Which is, I believe, supporting info for the theory that the chassis / shift-point / torque converter combo is what needs to be looked at next.

Bill

 

Its weird. Its transfering the power to the dyno but its not hitting the ground at the track apparently. Certainly makes the power expected out of that combination, and actually makes more than I would have thought Converter may be eating up some of it and not doing a good job at the track but I'd think it should go another 10mph faster than it is unless the car is alot heavier than what i am assuming. 388whp trapping 110 seems low as well given a 3450lb raceweight assumption. Whats the weather like out there? Hot/humid? That may be killing the times.

 

I find this article hard to believe but who knows, although Orr had a strong running HSR. Seems like most people are having issues or is it just me.

http://www.gmhightechperformance.com...roc/index.html

 

He wants a complete set of aluminum vortec style heads that will work well with his application. Who's got the answer?? These heads should be ready to bolt on and go with. Help him out!

 

What the87' said, I'd like to bolt down a set of vortec port style heads. I like to see my options (price ranges) and what they can get me. Obviosuly I need a set that flows better than stock vortecs, or can handle more lift. Also the next step would be upgrading to roller rockers, roller lifters, or a roller cam entirely since this seems to be a big power area for these motors. I'm wondering can i buy roller rockers and lifters and use them with a flat tappet cam or how does that work? Throw some head packages and good cams out there for me. I'd like to destroy the 300rwhp and torq mark. I'm looking to purchase asap.

 

The vortec heads don't flow that much greater than a stock L98 head, and both have to be modified to run a big cam, but you don't need a big cam to make 425 horses. Get a set of good heads, aluminum would be better to run at least a point higher compression on premium, and will run stronger, and thermodynamics of aluminum heads allow you to run a good 10.25:1 compression with no worries on premium. Also you can't run roller lifters on a hydraulic flat tappet cam. The roller cams offer smoother valve action, runs cooler, and offer faster valve action thanks to its design. To save money, get some edelbrock performer rpm heads, and go with a LT4 hot cam kit and it comes with the roller lifters. But if you don't have a roller block, you'll need to buy a cam with the link bar style roller lifters, comp cams has some good kits with them for a decent price. If you have a roller block, this will be that much easier. But with the right compression 10.25:1 or so, that LT4 hot cam, decent heads and the stealth ram, and along with roller rockers and a good exhaust, all with a good tune, your motor will be pushin 400 horses without much of a problem, as long as your bottom end is pretty fresh. Of course if you had free floating wrist pins for your pistons, and fresh bearings, that helps free up some power, and of course, with your new cam, install a double roller timing chain, and that frees up more power. So U need to see what kinda money you wanna spend on some heads, and you must remember, your whole motor is only as strong as its weakest link, and if your heads suck, everything else, just won't work that well. Just trying to help If you want my names Keith Houda on facebook, I have a nice video of my formula with my cam, I haven't added it to youtube yet, but it sounds sweet and runs real strong, even though it has the 700r4 trans and 3.27 posi 9bolt. I want a th350 trans, that'll help a lot

 

You need a better tune. The guy who tuned yours just made it worse IMO. Isn't running a flat tappet cam with TPI a no-no?

 

UPDATE:
Got a timing light and found I was set at about 22 degrees BTDC at idle. I set forward to about 15 degrees. The idle changed but there were no big changes in the power. This is with the new vortec Plugs installed and adjusting the valves all to a 1/2 turn and setting my Fuel Pressure back to 45ish. The car seems to pull maybe a wee bit better than it used to. Nothing radical tho. Keep in mind the compression test came back +-5 at 130 to each cylinder. I'm thinking my last test will be the leakdown.

For some reason my oil pressure is 50psi when cold and drops to about 18 when hot at idle. It does climb back to 30 or so when reved. ???

Like Orrs stated - my vortec heads are only or capable of .430 lift on the stock springs. My cam card says gross valve lift: .477in .480ex So does this mean i max my cams capability or valve movement at .430 lift? Thinking this is killing me if my cam is basically getting maxed at .430?. Heres all the info on the vortec heads...
http://www.sallee-chevrolet.com/Cyli...ads/Vortec.cfm

Ok so my Plan of Action starts with these
http://www.summitracing.com/parts/CRN-10309-1/

Put these on my heads and I get my lift back, but they are kinda pricey at $250.00 Or at least i could invest that money into a complete set of aluminum heads with the specs i need for my cam. Again monies not an issue here, and I'd like to be able to get past this head issue and just bolt a good set down. Just dont want to be half assing this again. Plus in swapping heads i can put a set of low profile gaskets on to fix the compression issue?

Guys, help me out as always and help me make the best decision and route
for the motor.

 

From what I've read your cam should work with the vortec heads pretty well since the lift isn't over .500". It flows pretty good on the intake side, but wow, the exhaust sucks!! That kit should be what you need to do your heads up properly and restore some performance. After that the heads should be crossed off the problem list.

 

Could the lift restriction cause my power to flat-line like this?

I spun the motor to 6500rpms or a little more last night and it felt like it was still pulling.

 

My setup is trapping at 105 mph too

AFR 195 Eliminator Heads
Comp cam (224/230, Intake .535 in/ Exhaust .544 in, 110LSA)
HSR intake
Moser 12 bolt with 3.73's


I did some tweaking to the chip, but I doubt I'm going to gain the MPH I'm looking for.

 

.430" lift is a safe number, .480" is the absolute max given the right conditions. Either way you need to make retainer to guide clearance since your cam is close/over .480" lift. Yes, your power will flatten out since your lift is limited to less than spec, so it's acting like a smaller cam in a sense. Once your parts are working together you will get the desired results. If you decide to install that kit make sure there is clearance between the retainer and the valve guide, it should be good for .575" but make sure. There is a certain 906 casting that doesn't flow as well at low lift due to the single angle grind on the inconel seat. These heads were found on the HD and 1-ton trucks, theres no way to tell the two apart from the outside though. If the heads were no good they wouldn't be so popular, L98s were good at the time but nobody went out of thier way to get a pair, unless they were aluminum. For a cam try comps 08-503-8, should fit the set-up very well

 

Could it be floating the valves? graph looks smooth so maybe not valve float but seems like power is falling off earlier than expected.

 

I need a set of heads with vortec ports that i can bolt down to handle the lift of a 280XFI cam.

http://www.jegs.com/i/Comp-Cams/249/...oductId=757952

This is what i want to do. Has anyone seen any race ready heads?

 

Here read this http://www.nastyz28.com/forum/archiv...p/t-56505.html. Lots of info on these heads. If your looking for a set of heads to bolt on with that cam, AFR 912s would produce the best results $1,464.95 summit. Edelbrock E-tecs are $1159 but with the high lift of that cam you will need to change the springs out, so you will need to add the price of the springs. The operating range of that cam is a little low for te specs, I'd figure with that lift the redline would be 6500rpm or more. With that cam you will need a 2500-3000 stall. Whats the car going to be, daily driver, weekend warrior? That would help so we know what would work best for your situation.

 

Thinking these heads with the 280XFI cam
http://sdparts.com/details/scoggin-d...nter/sd8060ra2

 

"Generally speaking, Vortec's stall at between .500” and .550” valve lift. This is where flow actually begins to decrease. But their true strength is low lift flow which gives more area under the total flow curve. And if you think about it how long are your valves at peak lift? They spend much more time at .400” and below, where the Vortec’s outperform most other heads." Just a quote from the link I posted. Just because you can now put a high lift cam in doesn't mean you can go all out on lift. Atilla the Fun suggests a cam like the LT4 hot cam for the vortec hsr 350. This may be upsetting to you, being limited on options, but its best you know your options before you spend the money.

 

You want to focus on the flow numbers at around 87% of peak cam lift. So to really work a set of vortecs which flow well in the .450 range, you should run a cam thats around .517" lift. between .450-.500 is generally where vortecs work best, so cams with .510-.570 should well.

 

This is the kind of info I like, guys! Keep it coming.

Its sounding like the bolt on springs from chevy and the LT4 Hot Cam may be my best bet.

 

What you should really do, is talk to some engine guys at a engine shop, that build serious motors, and find out what would be a good cam for what you have already. Too big of a cam, you'll have to change your roller lifters, theres a couple different varieties out there, but you may need to go with a different set. I got lucky in my bird, even though it was the stock cam, it had some nice aftermarket cranes in it. That 08-503-8 cam, I almost used, but then I found mine from a previous owner, and it works great in my ride. That dyno curve, looks like your running a stock chip in the computer, because after 4750 with a stock TPI intake, it doesn't make any power beyond that mark, so the computer pulls some timing and fuel out of it, so even though its running at higher r's, its just not making any more power. So it looks like your tuning guy, used stock fuel and timing curves and probably didn't even add more fuel to it. But keep in mind, your base timing, fuel pressure and TPS voltage all has to do with how your motors running. But those heads with that cam, sure as hell isn't running right at all, you just kinda destroying your power and valvetrain.

 

I would go with the comp 08-503-8 cam over the hot cam and stick with 1.5 rockers unless you plan on modifying the heads for pushrod clearance. Get your compression up to 10:1 and you should easily pull 300hp on the tune you have. Then get a better tune, not from the guy who did it before (I'd beat a $600 refund out of him, but don't), go to www.fastchip.com and get a custom chip made for $350, crons mentioned them a dozen times and they look to be pretty good.

 

Thanks for all the help guys. I'm attacking this from all angles and have another thread going which you're more than welcome to post in.

https://www.thirdgen.org/forums/alte...ml#post4690724

It's looking like the LT4 hot cam and a set of springs. Actually I'll need the 1.6rr's, roller lifters, new pushrods?, and everything else to go from a flat tappet setup. I've seen some LT4 kits but i'm unsure if they come with everything I need. I'm getting really close to buying the stuff or calling up comp cams and see what they recommend, but I'd like your guys input first.

Modifying the pushrod holes doesn't like sound like that big of deal to me, maybe it is? The heads need to come off as is so I can run new gaskets.

 

You can run 1.5's with the hotcam. Wont give up much going from .525 to .490 lift on vortecs.

Just not 100% sure how to get the hotcam to work in a non roller block. If you can, then I'd just get the hotcam from whereever you can for cheap. Try forum classifieds.
Then buy different springs. The ones in the hotcam kit are marginal at best. They BARELY handle the .525"lift and really dont have much spring pressure for a 1.32" spring. I'd get something else like beehives or patriot gold's or even comp's 987's or similar, even tho the comps are a fat spring. Beehives would be ultimate drop in on a vortec head and could provide you with up to .525" lift on stock head without having to machine down the guide bosses.

Lifters i'd guess you'd need retrofits? Not exactly cheap.

 

Like Bill said, the dyno numbers are real close to comparable #'s other cars have done, but the dyno testing is done at sea level and our cars have to run at Fontana where the ADA is 3000-3500. (the day he ran....3500 I ran the same day and was off 3-4 tenth's)

If you saw the dyno graph I think you would understand why the performance is not looking so good with his combo.

At 2500-3000 it's like 125-150 HP and his converter was 2600.
That is why he changed to a SS4000.
His combo doesn't even begin to produce power until 3600-3800. (350-360)
So imagine trying to lauch a 3800# car with 125-150 HP.

No, we haven't because Bill is the only one around here with an HSR, but those #'s sound about right for an out of the box HSR.

 

How much torque does it make there? I will have to look for the thread with his graph.

Does make sense with a cam that big that it wouldnt make strong power until in the 3000 range+. I've been helping a guy with a 280xfi cammed HSR motor that hasnt quite been running what we think it should. It has 3600 stall but doesnt seem to be getting off the line as hard as I would expect. Only low 1.8 60 foots. Plus I think the valves may be floating since the springs arent very strong and that cam has aggressive lobes.

 

"Happy dyno?? those numbers rival my old 383 for hp, i'd expect mid 11's out of that combo"

He was on the same dyno I was on the same day. Mine was at 370rwhp with my new Yank PT4000 torque converter. I ran a 12.09 @113mph with the terrible 3500' density altitude. With anything like normal air I would have been into the 11's. With sea level air I would have been well into the 11's.

I think Dyno Don has it right. He needs the right torque converter to match his motor. I believe he now has it with the Yank SS4000. This will keep his motor in the sweet spot running down the track.

However Bill's new problem is I have my new motor installed.

 

Whatever I do, the HSR likes a big stall right? I can at least start there, order that this weekend and put it in to see how the car responds to that. Right now my car can't even turn the tires over anymore

yank ss4000 a good choice? the one for the 4l60

 

"yank ss4000 a good choice? the one for the 4l60"

Maybe? Have you had your motor on the dyno? If so where was peak torque?

 

Man, this is funny, I had my heads, stock cam, 1.6 RR, HSR, Longtubes and true duals and my motor was pushing 300 horses man and I had the stock tune, with just 24# injectors, u just have to pick the right parts.

 

[quote=1989GTATransAm;4691351
However Bill's new problem is I have my new motor installed. [/quote]

Uh huh.....I'm pretty sure my only hope is the horsepower-to-weight ratio factor

 

And then there is his other problem........

My new combo ....uh yours He He

 

Peak torq was at 4250rpm. I'm confused what to do here. I don't want to get the car running right and figure out I'm not making the power I want to. I want to be past the 300 rwhp and torq mark. I mean what would you guys do in my position?

 

Well if I knew the motor was mechanically sound and the dyno tune was accurate, and it still wasnt making power with those heads and cam, I'd change the heads/cam

But problem is we all expect more power out of this setup. I would verify you have good ring seal and actually have good compression. Just re-reading this thread, you have had some issues with this motor, from tune problems to other things.

If the stock crate was 9 to 1 with 64 cc head, and you went to a 68cc head, its now around 8.7 which is abit low for any good cam.

I'd tear it all down, shave the vortecs down as low as you can. 62-64cc to get compression back up abit. If you can go lower, go for it. May need to mill the intake manifold as well to seal well on the shaved down vortecs.

Put in new springs spec'd for the cam. I like rollers and a LT4 hotcam can work well on that setup. Just need to convert it to a roller block with retro lifters. Not sure how to use a OEM roller cam in a non roller block, I think you can use the retainer plate as a spacer.

Even the flat tappet cam should work well. Just have the vortec's setup with the right springs since you said they are stock now.

Assemble the motor carefully to make sure no leaks/vacuum leaks/etc and retune it. That setup should make some power.

But even with low compression, i still predict 340-350 crank hp with that setup. Cranking compression is around 130 psi with that cam and 8.7 to 1 static so it looks to match your results

 

"Peak torq was at 4250rpm"

In that case I would go with the Yank SS3600.

 

I would hold off on buying a converter if your going to change your set-up betsy. Numbers are going change if that's what you're going to do, so plan accordingly.

 

Leak down into action asap. Orr, we did decide heads did NOT change in cc's. And figure 340-350 at the crank would stll be closer to 300 at the crank.

 

"The more I talk to people the more I get confused."

There is more than one way to build a motor. Talk to Joe Sherman or John Kasse and you will get two different answer on some things. However they both build great motors.

 

yeah 340 ish crank should be close to 300 wheel. Thats why I am abit concerned with this setup. Not sure whats going on. Maybe the cam is installed off its correct intake centerline? Valve floating? tune? conservative dyno?

Try racing it down the track and see what it does again. Should trap more than 105mph if its 300whp.

 

This is what the guy at Comp Cams told me to put on the car.

http://www.summitracing.com/parts/CCA-26915-16/

and

http://www.summitracing.com/parts/CCA-787-16/

 

Interesting... I'd use the better beehives for the same price, the 26918's

http://www.summitracing.com/parts/CCA-26918-16/

More pressure on seat so much better valve control. 1989GTATransAm ran old style beehives that were suppose to be 130lbs on the seat at installed height, but after alittle bit of use they wore out and only spec'd out at 100-105 lbs seat pressure. He had bad valve float problems with his XFI268.

I'd run more spring. 26918's should be recommended. Comp changed their supplier since the early batch of springs had breakage problems. The newer supplier has better quality although I do not know who is making the springs.

PAC springs also has a few beehive setups similar to the comps and other higher pressure versions that can also be considered if you ever use a more aggressive cam.

 

Hey whats up, long time no post? Get anything going yet? I pulled my hsr off to get it powdercoated and noticed a few of the intake bolts were rusted while others weren't. Never lost any water or had water in my oil so I guess its alright. I used a set of l98 gaskets to put the intake on the 1st time, had to cut some material out but otherwise they lined up good. This time I'm going to use Fel-Pro 1255 gaskets. I think I found the source of my high rpm backfires, my 3" maf housing is causing a lean condition and reslting in a pop. Never really thought about it, actually forgot about it, spent a whole 2 hours machining it lol, oh well.... So whats your combo going to consist of??

 

My Ed Wright tune/stock tune when cold with my setup would pop when cold, because it delivers a lot of fuel when its cold, so it kinda blubbers, just when cold, but its not even that bad, So I don't even worry about it. I mean I'm running 51psi of fuel pressure and it seems to run the best.

 

Yeah but this delivers a shotgun blast when it happens, not really good for a new engine I'm sure. Its wierd though, it smells rich, but the plugs are barely tan and I get a code for lean exhaust. I'd figure with the 26# injectors and stock tune it would be running rich, but with the extra i.d. of the maf housing I think I'm fooling the computer into thinking its not flowing alot of air so its not giving enough gas in the upper rpms. Thats the only logical explanation I can come up with for the situation.

 

Nothing going on really. School and women keep busy enough. Need to put the new springs on still. My buddy rob (ACCLR8N) put a scan tool on the car and said it looks like the computer is staying in open loop mode..

Stuck on this low compression issue. Guess I need to figure out valve to piston clearance? so I can get the heads machined down. Or do I even need to do that? But yeah need to bump the compression up.

After that its off to find someone who knows how to tune this thing.

 

My engine was built like a stock engine with better parts, so my compresion ratio is like 9.3:1-9.5:1, not alot but it runs good on crappy gas. All I wanted was a good mannered daily driver and I'm definatly happy with the results. Hang in there, once things are right you will be happy. It took me a year before I was able to hit 3rd gear and as much as I wanted to set the car on fire I'm glad things worked out. Still want to see it burn sometimes........

 

Instead of milling the heads, the cheaper way to go is to get a set of head gasket by Mr. Gasket from Jegs part # 720-1130 with an .018"-.020" thickness compressed. These will definitly get the compression up to 9.5-1 without machine work to the heads. The heads gasket you may be using are .038". What we use for our heads down hear in Socal are stock chevy head gasket and they are .028". Fel-pro are .038"