AFR 180 on 383
Thread Starter
Instructor
Joined: Mar 2002
Posts: 140
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From: east hampton ct
AFR 180 on 383
I am faced with building a new motor this winter as I just lost a rod bearing in my 350. I have decided to build a 383 however I will be reusing my older AFR 180 heads which are a little small for a 383. I will either be upgrading my existing 010 two bolt block with splayed center caps or purchasing a Dart SHP block. Does anyone know a realistic limit of hp that can be achived with these heads keeping it at around 6,000 rpm. That hp number will help me decide whether to upgrade my old block or go to the SHP block.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
What are your power expectations. A Dart block is a waste of money if you are only going to push 400 to 450 HP. The 180 heads are definitly to small for a well breathing 383. My older 190s are barely enough for my 385 motor. They do make HP but I wish I had a set of 210s for it.
Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
The 195 eliminators are the best but look here at the flow numbers for your old 180 compared to the 195 eliminators @ .400 lift. You will be shocked what these 180 heads flow. They flow better than most 210 heads. I don't think the difference is worth dishing out the big bucks for new heads if your running 6000 RPM and under. You might give up a little peak HP but you will pull good power thoughout the powerband.
http://users.erols.com/srweiss/tablehdc.htm#Chevy
http://users.erols.com/srweiss/tablehdc.htm#Chevy
Thread Starter
Instructor
Joined: Mar 2002
Posts: 140
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From: east hampton ct
My target goals are in the 450 range for hp. One of the reasons I am considering the dart block is its fully machined cost is in the $1,700 range and its set up for a factory roller cam. By the time I have my block machined and put in retrofit rollers I'm not saving a whole lot and the dart block is a much nicer piece.
I realize that the 180 heads are not optimum for a 383 but they are paid for and only have about 5,000 miles on them. Their flow capability and wanting to maintain street manners is the reason I'm setting 6K as an rpm limit plus I'll be using a hydraulic cam.
I realize that the 180 heads are not optimum for a 383 but they are paid for and only have about 5,000 miles on them. Their flow capability and wanting to maintain street manners is the reason I'm setting 6K as an rpm limit plus I'll be using a hydraulic cam.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
My target goals are in the 450 range for hp. One of the reasons I am considering the dart block is its fully machined cost is in the $1,700 range and its set up for a factory roller cam. By the time I have my block machined and put in retrofit rollers I'm not saving a whole lot and the dart block is a much nicer piece.
I realize that the 180 heads are not optimum for a 383 but they are paid for and only have about 5,000 miles on them. Their flow capability and wanting to maintain street manners is the reason I'm setting 6K as an rpm limit plus I'll be using a hydraulic cam.
I realize that the 180 heads are not optimum for a 383 but they are paid for and only have about 5,000 miles on them. Their flow capability and wanting to maintain street manners is the reason I'm setting 6K as an rpm limit plus I'll be using a hydraulic cam.
Racer
Joined: Dec 2008
Posts: 300
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From: Toms River NJ
you could/should make up to approximately twice as much HP as the CFM your heads flow at the cams max lift. if you cam has .500 valve lift, and at that lift your heads flow 250cfm, you can expect to make a little less than 500 HP. if everything is matched and optimized, etc.
I agree that for your target hp level the dart block is a waste of $$, unless you get the 4.125 (DO IT! DO IT! DO IT! DO IT!
) in anticipation of future power upgrades.
I agree that for your target hp level the dart block is a waste of $$, unless you get the 4.125 (DO IT! DO IT! DO IT! DO IT!
) in anticipation of future power upgrades.
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Brett Foote
Supporting Lifetime Member
Joined: Oct 2005
Posts: 454
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From: Lovettsville Virginia
My target goals are in the 450 range for hp. One of the reasons I am considering the dart block is its fully machined cost is in the $1,700 range and its set up for a factory roller cam. By the time I have my block machined and put in retrofit rollers I'm not saving a whole lot and the dart block is a much nicer piece.
I realize that the 180 heads are not optimum for a 383 but they are paid for and only have about 5,000 miles on them. Their flow capability and wanting to maintain street manners is the reason I'm setting 6K as an rpm limit plus I'll be using a hydraulic cam.
I realize that the 180 heads are not optimum for a 383 but they are paid for and only have about 5,000 miles on them. Their flow capability and wanting to maintain street manners is the reason I'm setting 6K as an rpm limit plus I'll be using a hydraulic cam.
I have a fully machined 383 block with 4 bolt mains that I no longer need (going big block). It is .030 over and has new cam bearings and brass freeze plugs installed. I'm asking $950 for it, but open to offers. It's ready to build as is for a lot less than that Dart block and should easily handle the 450 hp you are after - that's what I was going to build.
I'll send you a PM. Let me know if you are interested.
Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
2 flow tests on the old 180 @ .500 lift
255 190
260 204
2 flow tests on the new 195 eliminator street @ .500 lift
270 207
277 207
Look at the difference. Look at the cost. Look at your power goals (450 hp) and under 6000 RPM redline. Add the cost of a new intake that matches the ports on the AFR 195's. If you are going with a new block the dart with the 4.125 bore is the way I would go too. What CC are the chambers on your heads?
255 190
260 204
2 flow tests on the new 195 eliminator street @ .500 lift
270 207
277 207
Look at the difference. Look at the cost. Look at your power goals (450 hp) and under 6000 RPM redline. Add the cost of a new intake that matches the ports on the AFR 195's. If you are going with a new block the dart with the 4.125 bore is the way I would go too. What CC are the chambers on your heads?
Last edited by 63mako; Nov 12, 2009 at 11:53 PM.
Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
A 2 bolt main block and using a 3.750 stroke which adds more side loading to the caps which will make the caps walk as I repair a lot of blocks because guys have read in a magazine 2 bolts block are good up to 500 horse, Personally I have not seen this yet and buy what GM rates their blocks at they don''t either.
Here is a link to look over.
http://forums.corvetteforum.com/c4-t...ps-1992-a.html
If your buying a used block make sure its its been sonic tested and plated honed and if it was bored off from and unsquared deck I would pass on that one.
The Dart SHP block is the way to go as we have sold about 45 of them this year with no problems.
Good luck which ever way you go
Here is a link to look over.
http://forums.corvetteforum.com/c4-t...ps-1992-a.html
If your buying a used block make sure its its been sonic tested and plated honed and if it was bored off from and unsquared deck I would pass on that one.
The Dart SHP block is the way to go as we have sold about 45 of them this year with no problems.
Good luck which ever way you go
