ques about stock l98 heads and porting?
#2
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Joined: Jul 2003
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From: Lima, OH
Car: '89 Formula 350 & '86 Z28
Engine: L98 & 355ci
Transmission: 700r4 in both
The only way your 64cc heads will change(doing port work) is if you do any work to the combustion chambers. Porting the heads makes the intake port larger, not combustion chambers. I think you might be confusing the numbers a little.
combustion chambers are the typically 58cc-76cc
Intake ports are the numbers that are typically 160cc-220cc
combustion chambers are the typically 58cc-76cc
Intake ports are the numbers that are typically 160cc-220cc
#4
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Joined: Apr 2002
Posts: 1,119
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From: Armpit state
Car: 71 Nova
Engine: Superramed 383, Topline heads
Transmission: 700r4
Axle/Gears: 8.2 posi 3.08
Dont forget the most important part the combustion ports. This is really where most of your porting should be done since not much is gained from the intake ports. Dont take it from me but a professional.
Heres an excerpt:
"Gasket-matching the intake ports is an easy task, but it’s only a small step in moving air through a head. Porting the walls of the runners is time consuming and offers almost no flow improvements"
Heres another:
"Cylinder head porting is more about how well air flows through the port rather than port size"
article
Heres an excerpt:
"Gasket-matching the intake ports is an easy task, but it’s only a small step in moving air through a head. Porting the walls of the runners is time consuming and offers almost no flow improvements"
Heres another:
"Cylinder head porting is more about how well air flows through the port rather than port size"
article
Last edited by shaggy56; 01-04-2004 at 09:18 PM.
#5
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Joined: Jul 2003
Posts: 1,096
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From: Lima, OH
Car: '89 Formula 350 & '86 Z28
Engine: L98 & 355ci
Transmission: 700r4 in both
Thats right, porting is done in bowl area, underneath the valves(which will enlarge port size). Thats where people port to get airflow increases. I was trying to clear something up for him combustion chamber vs. intake port)
Original poster: If you look in that article in the picture where he uses dummy valves to clean up the combustion chamber, thats how you go from 64cc to 66cc...
Original poster: If you look in that article in the picture where he uses dummy valves to clean up the combustion chamber, thats how you go from 64cc to 66cc...
#6
Sorry to bring this one back, but I didn't want to start a new thread for a question that seems appropriate for this thread...
Are L98 heads worth the time and money invested in upgrading? Let's assume an extremely tight budget and that the heads are already part of a complete L98 engine that is in need of a rebuild. Thanks in advance for any responses.
- 89_IROC
edit: I forgot to mention that these are iron heads from a 350 IROC.
Are L98 heads worth the time and money invested in upgrading? Let's assume an extremely tight budget and that the heads are already part of a complete L98 engine that is in need of a rebuild. Thanks in advance for any responses.
- 89_IROC
edit: I forgot to mention that these are iron heads from a 350 IROC.
Last edited by 89_IROC_98U; 01-07-2004 at 02:22 PM.
#7
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Joined: Jul 2003
Posts: 1,096
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From: Lima, OH
Car: '89 Formula 350 & '86 Z28
Engine: L98 & 355ci
Transmission: 700r4 in both
On a really tight budget its best to run what you have already, but make them as good as they can be.
Port em yourself and get as much as you can! Then save for heads in the future.
Port em yourself and get as much as you can! Then save for heads in the future.
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#8
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Joined: Jan 2002
Posts: 1,370
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From: Las Vegas, NV
Car: 1990 Iroc-Z
Engine: L98
Transmission: 700R4
L98 can flow really well actually. Its a direct product of how much time you're investing. If you can find the time to do all the port work yourself, you can make L98 heads performance heads. If you need to pay a shop - I'd just buy some out of box Worlds or Trickflow.
Bottom line:
You do - yes.
You pay - no.
Bottom line:
You do - yes.
You pay - no.
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