Project 3400 Roller Cam Block (Page 28/82)
sleevePAPA JAN 28, 02:32 PM

quote
Originally posted by Joseph Upson:

I know there's a bit more potential left in what you're doing Lou, but at this point it's about like digging for goal in an abandoned mine, you might get lucky to make the effort worth it. I'd much like to see you conform to building up a later model engine as opposed to cannibalizing it. Understand that the numbers Superdave posted were from a second dyno after some changes, the first put out a little less hp and more torque, basically a change of balance, not to mention he didn't take advantage of the opportunity to bump up the compression 1 to 2 points to take advantage of his cam which might have dragged his tq up to 300 lb/ft at the wheels also.

Here is a video of the motor idling along with his cam specs and it sounds nice. If you just don't want to deal with the aluminum heads or non stock look I understand, otherwise I think you should swap the complete 3x00 motor and let "iron side" go.

https://www.youtube.com/watch?v=XP048yTMb_8




Dave initially had higher compression(iirc 10.9:1) but found that with the high lift of the cam, the exhaust valves were kissing the pistons. he was using graphite .040" headgaskets used on the ironhead 3.4 660.

Lou, the D shape exhaust port on later Gen III heads optimized the short side radius increasing the flow signifcantly. ports were also raised to create a more direct transition to the valve. also, the canted valve decreased shrouding as well. proof is in the pudding, a Gen III topend will build on your current setup. keep in mind that the assembled steel factory camshaft is somewhat weak and has been known to break, WOTTech has some good grinds that can be matched to your setup.
Will JAN 28, 03:40 PM

quote
Originally posted by lou_dias:

I'm starting to see less and less reason as to why the heads are the improvement people think they are.



You're kidding yourself. The Gen III and Gen IV heads are far and away superior.

[This message has been edited by Will (edited 01-28-2013).]

lou_dias JAN 28, 04:38 PM

quote
Originally posted by Joseph Upson:

I know there's a bit more potential left in what you're doing Lou, but at this point it's about like digging for goal in an abandoned mine, you might get lucky to make the effort worth it. I'd much like to see you conform to building up a later model engine as opposed to cannibalizing it. Understand that the numbers Superdave posted were from a second dyno after some changes, the first put out a little less hp and more torque, basically a change of balance, not to mention he didn't take advantage of the opportunity to bump up the compression 1 to 2 points to take advantage of his cam which might have dragged his tq up to 300 lb/ft at the wheels also.

Here is a video of the motor idling along with his cam specs and it sounds nice. If you just don't want to deal with the aluminum heads or non stock look I understand, otherwise I think you should swap the complete 3x00 motor and let "iron side" go.

https://www.youtube.com/watch?v=XP048yTMb_8


Sounding "nice" is a matter of taste. I personally don't like the open exhaust sound. I dynoed my car the same way it drives on the street.
While I had no cat, I used the Trueleo headers into 2.5" piping following the stock routing with a Flowmaster 55 series muffler and two outlets.
I'm no longer using the Fiero intake other than the lower part. I don't have a current dyno but I know how much power my 1997 6speed with cat-less exhaust Corvette made, how much power my stock '88 Formula makes, my 4.9 GT 5spd(172/265) makes and how much this Fiero makes. With the Trueleo intake and my current tune, my 4.9 has no chance of being near my v6 hybrid.

Here's my 3.4 v6 doing a sub-20 second lap with a bogged launch.
https://www.youtube.com/watch?v=kbaujyDgT3Y

When my 4.9 car had a turbo 3.1 (Voytek's), the best I did was about 20 sec when the motor was cold
http://www.facebook.com/pho...82870&type=3&theater

same car now with 4.9 doing a 21 second lap with my friends mentioning my axle-snapping incident (not knowing it was my other Fiero)
https://www.youtube.com/watch?v=WZbYLaI2B5U

As you can see they are about 2 seconds apart on the same track as it stands right now.
ericjon262 JAN 28, 04:42 PM

quote
Originally posted by lou_dias:
In a turn, flow is more important in the outer diameter than the inner.



This is more important in a boosted application then a N/a application, remember, the air is being pulled down, nut pushed, so it's going to go for the shortest distance possible.

------------------


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

lou_dias JAN 29, 08:02 AM

quote
Originally posted by ericjon262:
This is more important in a boosted application then a N/a application, remember, the air is being pulled down, nut pushed, so it's going to go for the shortest distance possible.


That's a thought but is there any scientific data behind that? To me, flow is flow and it doesn't matter what's driving the pressure imbalance. I could be wrong, but I just want to see it. Thanks.
Joseph Upson JAN 29, 08:08 AM

quote
Originally posted by lou_dias:

That's a thought but is there any scientific data behind that? To me, flow is flow and it doesn't matter what's driving the pressure imbalance. I could be wrong, but I just want to see it. Thanks.



You can only pull about 32" of vacuum but you can build a lot of pressure to force through a given passage. The port characteristics still have an effect but yes you'll be able to over come some flow inefficiencies with forced induction that would be more of a hindrance naturally aspirated.
lou_dias JAN 29, 10:03 AM

quote
Originally posted by Joseph Upson:
You can only pull about 32" of vacuum but you can build a lot of pressure to force through a given passage. The port characteristics still have an effect but yes you'll be able to over come some flow inefficiencies with forced induction that would be more of a hindrance naturally aspirated.


I'm talking about flow characteristics of pulling versus pushing. To me it shouldn't change and that the outer diameter is what's "more" important. To me, you would want to square the two corners of the outer diameter of a tube to increase flow compared to the inner area. While increasing the inner area may increase overall flow, I am just questioning the efficiency of one over the other and specifically in the case of a NA motor. GM doesn't always do things for the reason you think. The shape of the intake ports on the head were mandated by the splayed valves. The pushrods would be in the way otherwise. They may have made the total area bigger over time when compared to the cast iron heads, but that is probably more because they don't sell a car with factory cast iron heads any more and hence a port and polish(bigger ports) is what would be standard today if they sold a 3X00 with cast iron heads today as the displacement increased.

[This message has been edited by lou_dias (edited 01-29-2013).]

Will JAN 29, 10:49 AM
Flow through a passage or orifice is related to, IIRC, the square root of pressure difference across that orifice


quote
Originally posted by lou_dias:

I'm talking about flow characteristics of pulling versus pushing.



There is no pulling, only pushing.

[This message has been edited by Will (edited 01-29-2013).]

lou_dias JAN 30, 10:16 AM

quote
Originally posted by Will:
There is no pulling, only pushing.


Yea, was getting confused with the intake side in a boosted and non-boosted application. On the exhaust, the piston is always coming up to push the exhaust out which re-iterates my point about where GM *should* have opened up the exhaust. Too bad I sold my Gen3 heads when I did. I never really had time to inspect and compare them...
lou_dias FEB 09, 03:20 PM
So seeing as how the 3.1 is the only motor to have all generations of heads...

Gen 1: 150 hp (iron)
Gen 2: 140 hp (aluminum, but intake ports are fail)
Gen 3: 170 hp (roller cam with bigger ports over gen 2)

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.