Yellow Bullet Forums banner
Cancel
Create thread New Garage Forums

Looking for best BBC head for the money

3 reading
Jump to Latest
13K views 24 replies 10 participants last post by  wolf Wengler  
#1 ·
#5 ·
In salt water? Your better off with a steel head I think.
 
Save
Reply Quote Like Like
#7 ·
Honestly, I know it sounds strange, but I would look at the CID heads JK400 heads and matching intake. There not too pricey and I think the 383CFM @ .700 is nice too. Modern tech for old BBc.

A more conventional bang for the buck would be the AFR 265/290 heads. Little ovals keep velocity up as well as powering thought the RPM range as your not going to be screaming this thing to 8500.

FYI
 
#8 ·
Done a lot of marine engine builds over the years and my recommendations are two depending on use. For the best "Bang for the Buck" Pump gas compressions @10.0 to 1.

1. For a hydraulic roller engine of 450-600HP in an aluminum head is the ProMaxx 317 BBC head with Inconel exhaust valves for about $1700 per pair assembled.
aluminum should use closed cooling but if a lot of freshwater use or good flushing after use aluminum will be fine. This head flows 385cfm @.600 lift with a 317cc port!

2. For an iron head in same use 450-550HP I would use the Engine Quest CH454A 320cc head also with Inconel exhaust valves.
Head flows intake at 355cfm @.600 lift. They will be about $1200 per pair assembled.

Both these heads exhibit good quality castings, nice accurate machining and can be had with good parts, ie: valves, springs, retainers, rocker arms and such. JMHO
 
#12 ·
No way a ProMaxx head flows 385@.600 out of the box.
Factory valve job, Rev intake w/30* b/c flows 361@.600, 375@1.0 on a 4.31 bore. With our valve job it flows 372@.600, 380@1.0 on 4.5 bore and with a 2.30 valve it flows 381 @ .600. and 396@1.0 on 4.50 bore with just a bowl and chamber blend.
 
#13 ·
No mistake in my post as I am using the manufacturers independent test claim of 385cfm with a 2.250 intake valve. Great for performance boat use as the 317 cc port should maintain some good mid range power and torque with the right camshafts.

Not familiar with Foxwells test but I tend to think there is sometimes some bias with individuals who sell and promote a lot of other product? Stan Weiss's tests show them at 375cfm out of the box, still damn good numbers for a very reasonable cost head? Good Flowz Eh! JMO
 
#17 · (Edited)
Rapidray said:
No mistake in my post as I am using the manufacturers independent test claim of 385cfm with a 2.250 intake valve. Great for performance boat use as the 317 cc port should maintain some good mid range power and torque with the right camshafts.

Not familiar with Foxwells test but I tend to think there is sometimes some bias with individuals who sell and promote a lot of other product? Stan Weiss's tests show them at 375cfm out of the box, still damn good numbers for a very reasonable cost head? Good Flowz Eh! JMO
Click to expand...
Not at .600".
No bias with my numbers. I try my best to provide the most accurate information possible. I spent over two weeks going through a complete calibration process on my bench with one of the leading airflow engineers in the country who used to work for Superflow. I can't say his name because of confidentiality agreements but needless to say you've heard of him. I didn't do that so I could bias my numbers. We sell lots of different manufacturer's heads and I'm what I would call "non denominational" when it comes to preferences. Biased numbers don't do me or any one else any good.
Personally I think the Pro Maxx is one of the, if not the best bang for the buck head on the market. We have Rockwell tested, weighed, checked machining, and flowed many sets. I have them on our flagship 532 making well over 800hp on pump gas. Very good quality casting. Very good part.
I'll look into the Flow Tech. Sounds promising.
 
#14 · (Edited)
Pro Maxx 317
2.25 valve, 4.50 bore, our valve job;
(good port/bad port / ex)
.2 161.6 / 163.2 / 123.6
.3 246.4 / 243.8 / 171.7
.4 308.8 / 297.3 / 217.2
.5 347.1 / 344.5 / 248.7
.6 362.3 / 372.8 / 263.3
.7 372.2 / 357.1 / 271.4
.8 376.4 / 365.2 / 277.2
.9 377.5 / 367.1 / 281.0
1.0 380.3 / 373.5 / 282.2

I think if they flowed 385@.600 I would say so... if I was trying to bias my numbers...
 
#15 ·
Pro Maxx out of the box, their valve job, Rev 2.25 w/30* b/c, 4.31 bore.

(good port / bad port / ex)
.2 155.3 / 158.8 / 117.4
.3 238.0 / 230.6 / 157.3
.4 294.9 / 287.8 / 190.7
.5 338.4 / 322.6 / 222.9
.6 362.9 / 346.6 / 250.7
.7 361.5 / 365.0 / 273.7
.8 370.2 / 357.7 / 284.4
.9 372.2 / 360.5 / 287.0
1.0 375.6 / 364.8 / 288.7
 
#16 · (Edited)
Thank you Scott, I had not seen your numbers or tests. The original OP is talking about 502/540 builds so we are talking a 4.500 bore and your tests indicate 372cfm @.600 which almost matches Stan Weiss's numbers so I will submit to those numbers. Pretty damn good for a $900 out of the box aluminum head! I will modify my opinion of your lack of bias, just keep it there. The beatings will continue until the moral improves! ;)
 
#23 ·
That data on that old Super Chevy article is about 6 years old and some iron head offerings have changed a bit. If your running off a trailer in fresh water I would not worry about aluminum heads. If you're a salt boater then I like the Enginequest EQ360 head for that size engine. Depending on how much money you are planning to spend either have someone take a pair of these and use a 2.30" intake and you should & almost must run an Inconel exhaust if you run some long hammer down runs. You can have just a bowl blend, good valve job and run them, or you can someone do some nice port work and get them up to 400cfm if your build needs that. Put a fresh water flush on the engine and every time you put boat on the trailer or in a slip, hook up the hose, idle the engine for 3-5 minutes and flush the engine. Salt belongs in the kitchen, not in a stored engine!
 
Yellow Bullet Forums
posts
24M
members
152K
Since
2005
A forum community dedicated to drag racing drivers and enthusiasts. Come join the discussion about racing, builds, pro mods, hot rods, events, turbos, nitrous, superchargers, and more!
Full Forum Listing
Explore Our Forums
Trash Or Be Trashed Naturally Aspirated Let's Talk Drag Racing Turbo Charged Nitrous - Induction Solutions