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| Project 3400 Roller Cam Block (Page 27/82) |
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lou_dias
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JAN 24, 12:52 PM
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| quote | Originally posted by DefEddie:
I will weigh the gen II and gen III heads when I get a chance.
I have a set of bare 3500 heads as well,and assembled 3.4 heads.
The genIII are currently set up with the break-in springs as I am using the TGP bottom end with a ceramic coated flat tappet cam.
The combustions chambers are being coated and they need to be assembled,don't really wanna pull them apart again.
The D port enhances flow,if you look thru your valve and out the intake where it comes into the bowl I bet it will look similar.
Most port work ignores the floor other than cleanup and reshaping is mostly to enhance the short side radius to a nice profile.
That is advice from someone I trust that does it for a living.
He said the ideal is if you can recreate the curve from a 4" diameter circle into the short side radius.
He does have extensive experience with the superflow and engine dyno at his work testing,but not with anything other than nhra stuff.
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My machinist did an amazing job. He ported and polished as deep as possible only backing off where he thought there might be a coolant passage near by.
He did the heads, once I saw the heads, I had had another guy do the intake in the pics I posted. When I saw the work he did on the heads I had him go over the 3 intake pieces of the Fiero intake that I had someone else do. So the pics you see of my intake weren't polished, he touched up the porting and polished them beyond what I have in the pics. I don't have pics because my installer needed the intake on the car to finish the job and give me the whole car running. I wish I had done the DAWG neck mod, but I didn't and I think that's why I hit the 4400RPM "wall"....a problem I don't currently have with the Trueleo intake....
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Will
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JAN 24, 04:00 PM
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I don't have a specific link, but the 270 WHP build has been on the www.60degreev6.com forum for a few years now...
The canted valve, which required the angle pushrod, is what really drove the port reshape. Don't kid yourself into thinking the ports are similar. Go find some flow numbers.
Indexing the plugs will NOT make up the difference between the iron head chambers and the aluminum head chambers. Builds with 12:1 comp run on aluminum head engines... Don't kid yourself about that either.
There's no such thing as pressure imbalance on the piston... Just like 1.75 isn't a better rod ratio than any other rod ratio.[This message has been edited by Will (edited 01-24-2013).]
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Joseph Upson
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JAN 24, 04:43 PM
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I have to agree with Will on this one Lou, the small block 400 had 5.565" rods so 5.7 can't be all that bad. The 60 degree forum has flow numbers floating around on the site for some idea and I recall the D shape exhaust port in the aluminum heads serving the same purpose as the fin in the cast iron heads, to improve flow. You can also find the Superdave there, I'm not sure about his work with a 3400 but I know his 3500 was at or near 300 hp naturally aspirated and as far as I know it has a cam, and head and intake work with the stock 9.8:1 compression so there was still room for improvement above that by swapping in the flat top pistons from the 3.6 DOHC. If I find the link I'll post it here for you to review.
He took down the graph but here is the thread.
http://60degreev6.com/forum...?highlight=3500+dyno[This message has been edited by Joseph Upson (edited 01-24-2013).]
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lou_dias
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JAN 25, 09:59 AM
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| quote | Originally posted by Joseph Upson:
I have to agree with Will on this one Lou, the small block 400 had 5.565" rods so 5.7 can't be all that bad. The 60 degree forum has flow numbers floating around on the site for some idea and I recall the D shape exhaust port in the aluminum heads serving the same purpose as the fin in the cast iron heads, to improve flow. You can also find the Superdave there, I'm not sure about his work with a 3400 but I know his 3500 was at or near 300 hp naturally aspirated and as far as I know it has a cam, and head and intake work with the stock 9.8:1 compression so there was still room for improvement above that by swapping in the flat top pistons from the 3.6 DOHC. If I find the link I'll post it here for you to review.
He took down the graph but here is the thread.
http://60degreev6.com/forum...?highlight=3500+dyno
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I like your comment in the thread.
"Not to knock the L67, but pound for pound the later 60 degree engines appear to be more efficient and powerful by design rather than fluke and I can't understand why the Fiero owners are even considering installing a naturally aspirated version of the 3800 or the 4.3L V6 in spite of that. "
-I've been saying this for years...
Still it's light on actual information. :/
Again, since I'm using the 3400 roller cam block, I can use the same cam...but again - what cam?
"274 WHP and around 250 WTQ.." I've matched the torque already when I had the Fiero intake, the only reason I didn't keep making power after 4400 is because of the Fiero intake neck and the fact that Ryan tuned for 12:1 followed by an epic fail trend to 10.5:1 in the upper rpm band... Despite that, I had a nice flat torque curve until the fueling went south.
I have since corrected the tuning to be 13.0:1 across the board and have switched to DIS, a '7730 running $A1, a Trueleo intak with an L98 (twin 48mm) throttle body. Please believe me when I say I am making more power than 187/249 currently. My peak is definitely ~5k rpm but I don't expect the car back until April so a dyno is a ways off. My advance at 4800 is 39 degrees.
Clutch dumps at 3000rpm still chirp the tires running 275 width street slicks on 17x10 wheels. The two times that I did 5k+ rpm dumps, I snapped axles...[This message has been edited by lou_dias (edited 01-25-2013).]
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lou_dias
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JAN 27, 10:11 PM
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Here you see how my ports on the Fiero intake that I used to dyno 187/249 compared to stock. This is with the intake shaved down flat with the rest of the bottom part of it.
Here you see how I compare to a 3400 intake:
What you don't see here is that while the 3400 ports look bigger, they actually aren't as big on the bend by a little bit at least on one side.
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Will
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JAN 28, 10:54 AM
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They also have a larger turn radius through the 135 degree bend than the Fiero parts do (particularly where you have the Fiero manifolds cut down... Have you checked to the sure you don't have a knife edge for the air flow to go around inside your port?) [This message has been edited by Will (edited 01-28-2013).]
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lou_dias
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JAN 28, 11:22 AM
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In a turn, flow is more important in the outer diameter than the inner. This is the same concept as to why the D shape improves flow on the exhaust ports. The opened up flat area would have to be on the outer diameter of airflow in a turn. My #'s don't lie and using the Fiero intake, without the "dawg" neck mod, I have posted higher #'s than any other Fiero intake-based motor, naturally aspirated of course. Like I said, my machinist was able to port and polish deeper into the flat area of the intake because he shaved it down.
Knowing what I know now about tuning myself, I would have loved to get my A/F ratio at 13.0 and also applied the "dawg" mod to see how far I could take it. There is a forum member offering to dawg-mod an intake but it's pricey. I will try to find someone to do it locally.
I still have this intake and the day my bone stock '88 formula dies, I will move this intake to that car along with another 3400/3500 bottom end. Seems pointless on a 2.8 ...[This message has been edited by lou_dias (edited 01-28-2013).]
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Will
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JAN 28, 01:28 PM
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| quote | Originally posted by lou_dias:
In a turn, flow is more important in the outer diameter than the inner. This is the same concept as to why the D shape improves flow on the exhaust ports. The opened up flat area would have to be on the outer diameter of airflow in a turn. My #'s don't lie and using the Fiero intake, without the "dawg" neck mod, I have posted higher #'s than any other Fiero intake-based motor, naturally aspirated of course. Like I said, my machinist was able to port and polish deeper into the flat area of the intake because he shaved it down.
Knowing what I know now about tuning myself, I would have loved to get my A/F ratio at 13.0 and also applied the "dawg" mod to see how far I could take it. There is a forum member offering to dawg-mod an intake but it's pricey. I will try to find someone to do it locally.
I still have this intake and the day my bone stock '88 formula dies, I will move this intake to that car along with another 3400/3500 bottom end. Seems pointless on a 2.8 ...
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D-shaped exhaust ports have the flat side on the short side of the turn.
A flow separation on an edge or sharp corner on the inside surface of a turn will kill flow throughout the entire passage.
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lou_dias
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JAN 28, 01:59 PM
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| quote | Originally posted by Will:
D-shaped exhaust ports have the flat side on the short side of the turn.
A flow separation on an edge or sharp corner on the inside surface of a turn will kill flow throughout the entire passage. |
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Well, that's kind of fail. I have the manifolds but not the heads to look at since I sold them. I'm starting to see less and less reason as to why the heads are the improvement people think they are. The intake is obviously an improvement over the Fiero intake...
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Joseph Upson
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JAN 28, 02:17 PM
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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[This message has been edited by Joseph Upson (edited 01-28-2013).]
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