Project 3400 Roller Cam Block (Page 30/82)
lou_dias FEB 09, 09:34 PM
double post

[This message has been edited by lou_dias (edited 02-09-2013).]

lou_dias FEB 09, 09:38 PM

quote
Originally posted by Joseph Upson:
The shortest distance between two points is a straight line, the aluminum head is closer to it than the iron head as it is already pointing downward at the valve more so than in the iron head and that seeming choke point may be for the benefit of velocity. Except for high revving, I believe you will lose a good bit of bottom end performance if you grind away the areas you have circled. The trend in the cylinder heads I've been seeing including the LS motors is a raised runner ceiling to reduce the angle before entering the cylinder. Whatever you decide I hope it works.


With the splayed valves, the air is going up at an angle (think left or right) then wrapping around and swirling in. This introduced extra length to the path.
In the iron heads, the vane is designed to help the direction change from upwards to down wards, there is no curving left and back around.

Funnily enough all my 3.4's have out torqued this stock 3500 LX9...though it is an auto...
http://www.youtube.com/watch?v=xNxETy9j-7s
You know what they say: dyno's don't lie. ;-)

[This message has been edited by lou_dias (edited 02-09-2013).]

ericjon262 FEB 09, 10:58 PM

quote
Originally posted by lou_dias:



One thing you don't see in this image is the narrower bottom end of the aluminum head. Also, the aluminum head goes flat then falls to the valve. The iron head offers a smoother transition and there is plenty of material that can be removed to increase flow.




see how much higher the port starts at in the Al head? helps with airflow by the air to take a strait path through the intake, instead of snaking around to find it's way to the port. as for the WTH in your pic, the valves in the Al heads are canted, this allows the valve to open away from the cylinder wall, which allows for more effective use of the curtain area of the valve. basically, air flows around the WHOLE valve instead of just around the short side radius like in old school style heads.

you say the iron heads flow better, how about posting some flow numbers to back it up

3500 heads, stock and ported, flowed at 28" on a 3.73"bore.



I don't see where you're coming up with the iron heads offering a smoother transition anywhere??? I have a set of iron heads here in front of me, I need no picture to tell me they are junk compared to the later castings.

this is the equivalent of saying L98 TPI heads outflow LS1 heads.... does anyone else think this is nuts?

Edit: I found flow numbers for these amazing iron heads, you ready for this???

[QUOTE=Will's Fiero;2927791]FLOW NUMBERS

I had two heads flowed.

code:

Lift      #1 Int    #2 Int
0.100     58.7      58.0
0.200     110.5     110.8
0.300     135.7     138.6
0.400     145.0     142.1
0.500     149.5     151.0
0.600     151.0     152.5

Lift      #1 Exh    #2 Exh
0.100     56.9      58.4
0.200     101.9     100.2
0.300     140.0     138.2
0.400     149.0     152.1
0.500     152.2     153.6
0.600     153.7     153.6
[/QUOTE]

LOL, my 3500 heads flow more at .25 lift STOCK than the iron heads flow at PEAK! LOL! and those iron heads were pro ported!



------------------
I know these lines Look crooked on paper, but I swear I've got them straight in my head.

Built not bought...

http://www.fiero.nl/forum/Forum2/HTML/119122.html

[This message has been edited by ericjon262 (edited 02-09-2013).]

lou_dias FEB 10, 01:19 AM
If you bothered reading your own link regarding the WOT port job, you'd read "most people think ported is ported".
Just comparing Falconer heads to Oreif's and you can see large variations.
I can't speak for Oreif's work but on the intake side, he exceed what I thought (and proved by looking at Oreif's) was a crappy job by Falconer.
Falconer added a D shape to the exhaust and exceeded Oreif's but Oreif's build include either Sprint manifolds or stock manifolds with the restriction removed. So basically he left the exhaust ports at ~7/8" or basically stock, and again you can see that in his exhaust #'s.

Let me remind you that my exhaust ports are at 1 3/16", not 7/8". On the intake, I left the vane but had it polished and my machinist did open up a lot coming in from the valve side and again I stress I had my ports fully polished. I don't have Oreif's or my own in had so I can really compare them. Oreif tuned the motor he built with the Trueleo perfectly to 197rwhp. With a better exhaust he could have done better. Me with a better exhaust but MUCH crappier intake and a mediocre tune did 187rwhp.

I'm not going to pull my heads just to flow test them. I will, however, post a dyno around May when I have the car back. As I've mention about 1000 times, I'm now running the Trueleo intake and a good tune and am making more power than 187 rwhp.

PS,
You do realize that IF I switched to aluminum heads to save 26lbs that it would be GEN2 so that I can maintain my headers, right? I actually have the 3400 intake in my basement but sold the Gen3 heads.
Will FEB 10, 07:51 AM

quote
Originally posted by lou_dias:

If you ask me, Gen 1 heads flow better than Gen 2 even if the Gen1 were stock (not ported). Gen 3 was an improvement over Gen 2, but its not proven better than ported Gen 1 heads yet.
We have GM flowing 275hp from a 2.8 probably with an open exhaust and we have a 3500 flowing 274 hp definitely with an open exhaust from Gen3 heads.



The 270 HP 2.8's were pure race engines... you know this. They had the Falconer throttle per cylinder intakes, custom long tube headers, REALLY big cams, sky high compression, and only had to live long enough to finish the race.

A Gen III/IV engine in the same state of tune would make over 350 HP.


quote
Originally posted by lou_dias:

Basically, iron head performance has been limited by bad intakes. Oreif built 2 3.4's with the 272 cam. One made 197 rwhp and the other 20X (I forget maybe 205rwhp). I wish he had used the 3400 block and cam. One was carbureted and the other used the Trueleo intake. I believe both used a ported stock exhaust. The Fiero performance problem lies in the intake and the tune, not the heads




And the first 3500's made 215 HP stock. IIRC, the 3400's were 185 HP in teh GAGT's.

[This message has been edited by Will (edited 02-10-2013).]

ericjon262 FEB 10, 10:35 AM

quote
Originally posted by lou_dias:

If you bothered reading your own link regarding the WOT port job, you'd read "most people think ported is ported".
Just comparing Falconer heads to Oreif's and you can see large variations.
I can't speak for Oreif's work but on the intake side, he exceed what I thought (and proved by looking at Oreif's) was a crappy job by Falconer.
Falconer added a D shape to the exhaust and exceeded Oreif's but Oreif's build include either Sprint manifolds or stock manifolds with the restriction removed. So basically he left the exhaust ports at ~7/8" or basically stock, and again you can see that in his exhaust #'s.

Let me remind you that my exhaust ports are at 1 3/16", not 7/8". On the intake, I left the vane but had it polished and my machinist did open up a lot coming in from the valve side and again I stress I had my ports fully polished. I don't have Oreif's or my own in had so I can really compare them. Oreif tuned the motor he built with the Trueleo perfectly to 197rwhp. With a better exhaust he could have done better. Me with a better exhaust but MUCH crappier intake and a mediocre tune did 187rwhp.

I'm not going to pull my heads just to flow test them. I will, however, post a dyno around May when I have the car back. As I've mention about 1000 times, I'm now running the Trueleo intake and a good tune and am making more power than 187 rwhp.

PS,
You do realize that IF I switched to aluminum heads to save 26lbs that it would be GEN2 so that I can maintain my headers, right? I actually have the 3400 intake in my basement but sold the Gen3 heads.



if the falconer port job is so crappy, then why is it your benchmark????

I will say it againstock gen 3 heads flow more at low lift then max effort ported Gen1 do anywhere, and continue to flow more to thier peak.

------------------
I know these lines Look crooked on paper, but I swear I've got them straight in my head.

Built not bought...

http://www.fiero.nl/forum/Forum2/HTML/119122.html

Joseph Upson FEB 10, 10:39 AM

quote
Originally posted by ericjon262:
if the falconer port job is so crappy, then why is it your benchmark????

I will say it againstock gen 3 heads flow more at low lift then max effort ported Gen1 do anywhere, and continue to flow more to thier peak.



I thought you were pressed for time, how bout you go finish putting your get-up together and leave Lou and those iron heads alone, I'd really like to see your motor go before you head out for Basic.
ericjon262 FEB 10, 10:41 AM

quote
Originally posted by Joseph Upson:


I thought you were pressed for time, how bout you go finish putting your get-up together and leave Lou and those iron heads alone, I'd really like to see your motor go before you head out for Basic.



Mine will get done, I'm at work right now...

------------------
I know these lines Look crooked on paper, but I swear I've got them straight in my head.

Built not bought...

http://www.fiero.nl/forum/Forum2/HTML/119122.html

82-T/A [At Work] FEB 10, 11:36 AM

quote
Originally posted by lou_dias:


Well, it's too late for me there. However, what's a reasonable price? I've seen camshafts go for $300 and $400 with no published specs... I did find one for $200 but the manufacturer never got back to me on specs... I want a street motor. Your cam defines that. 5200rpm peak if fine by me. Actually perfect.




Hey Lou, what do you think of these cams?

I found two that look semi-decent:

http://wot-tech.com/shop/gm...mshaft/prod_240.html
•254/252 adv duration
•199/200 .050" duration
•.480"/.456" lift @ 1.6:1 Rocker Ratio
•112 Intake Center Line
•113 Lobe Seperation Angle
http://wot-tech.com/shop/gm...mshaft/prod_241.html
•262/262 adv duration
•206/206 .050" duration
•.480"/.480" lift @ 1.6:1 Rocker Ratio
•111 Intake Center Line
•112 Lobe Seperation Angle


I've been told that with a 1.52:1 rocker arm, the 272 cam (272 duration) is the best for performance, etc... in the gen 1 block. So that's all I really have to compare to. I don't know enough about this stuff (usually rely on the experiences of others to determine what works best for cam selection). I'm under the impression that duration is better when used with our stock intake, simply because it allows more air to enter the chamber. Would that be a correct statement?

Since I can't use a 272 flat-tappet (or wouldn't want to) in a 3400 block, which would you recommend above? The one with the 262 duration? What difference does it make (if any) on duration if I use the 1.6:1 rockers like it's requesting? Seems to me that rocker arm ratio wouldn't have any effect on duration... but like I said, I'm not overly knowledgeable in this area.


Thanks!
lou_dias FEB 10, 06:08 PM

quote
Originally posted by 82-T/A [At Work]:
Hey Lou, what do you think of these cams?

I found two that look semi-decent:

http://wot-tech.com/shop/gm...mshaft/prod_240.html
•254/252 adv duration
•199/200 .050" duration
•.480"/.456" lift @ 1.6:1 Rocker Ratio
•112 Intake Center Line
•113 Lobe Seperation Angle
http://wot-tech.com/shop/gm...mshaft/prod_241.html
•262/262 adv duration
•206/206 .050" duration
•.480"/.480" lift @ 1.6:1 Rocker Ratio
•111 Intake Center Line
•112 Lobe Seperation Angle


I've been told that with a 1.52:1 rocker arm, the 272 cam (272 duration) is the best for performance, etc... in the gen 1 block. So that's all I really have to compare to. I don't know enough about this stuff (usually rely on the experiences of others to determine what works best for cam selection). I'm under the impression that duration is better when used with our stock intake, simply because it allows more air to enter the chamber. Would that be a correct statement?

Since I can't use a 272 flat-tappet (or wouldn't want to) in a 3400 block, which would you recommend above? The one with the 262 duration? What difference does it make (if any) on duration if I use the 1.6:1 rockers like it's requesting? Seems to me that rocker arm ratio wouldn't have any effect on duration... but like I said, I'm not overly knowledgeable in this area.

Thanks!


If you're going to use the roller cam block, don't waste your time on non-roller cams. There are performance roller cams available...but if you are just looking to be a street-sleeper, the stock roller cam makes plenty of power <6000rpm.