flow numbers for heads - Third Generation F-Body Message Boards

Go Back   Third Generation F-Body Message Boards > Tech Boards > Tech / General Engine

Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

flow numbers for heads

Thread Tools Search this Thread
Old 10-23-2000, 11:24 PM   #1
85cam's Avatar
Join Date: Dec 1999
Location: broadway NC
Posts: 138
Car: 85 s10
Engine: 350
Transmission: th400
Axle/Gears: 4.56

Classifieds Rating: (0)
Send a message via ICQ to 85cam Send a message via Yahoo to 85cam
flow numbers for heads

I have been searching the net and have come up short.

I need some flow numbers for my heads

casting number

Vader if you are listerning how about a little more help here!

I like to know all I can about what I got

3" custom FloPro Catback
14X3 K&N open element
15.6 best 1/4 mile before any mods
85cam is offline vBGarage Page   Reply With Quote
Old 10-24-2000, 12:12 AM   #2
Vader's Avatar
Join Date: Jan 2000
Posts: 18,015

Classifieds Rating: (0)


If the "461" is similar in design to the "462" camel hump heads, they are among the best-flowing stock SBC heads from the late '60s. They have relatively small chambers, and decent port volumes. Check the numbers at http://www.mortec.com for details and specs.

If you don't already have 2.02/1.60 or larger valves, the heads will work really well with those changes. Pocket porting the valve bowls and reducing the short radius on both intake and exhaust runners will open port volumes a bit and increase higher RPM power.

For an early factory head, they are actually very well designed. There is usually plenty of material to perform the necessary port matching and radius blending, unless your individual castings had an unusually high degree of core-shift. Even at that, the older stable cast iron can be easily nickel welded and machined to create some really impressive port openings on both sides of the head. Don't forget to trim the extra casting around the valve stem bosses. If you can find a service that will induction harden the valve seats before final grinding, it may be worth the few bucks you'd spend. If you're still planning on using the ZZ3 cam and necesarily larger springs, don't forget to install screwed rocker studs.

Another little trick to increase intake flow with the larger valves is to roll the valve margin into the valve face a little bit on a polishing wheel. Just removing the sharp corner on face-to-margin break can help get air into the chamber around the tightly shrouded chamber walls (P.S. - don't tell the Ford guys about that one since it works well on 302s, too.) The exhaust valves don't really seem to benefit from this, probably since they are smaller and less crowded against the chamber walls. Some of the builders I talk with claim another 5-8 HP on this alone. Then again, talk doesn't win races.

At a minimum, check the castings for straightness and cracks. Perform all the machining you want, then clean them thoroughly. Old heads and cases can really get some scale buildup in the coolant passages, and the last thing you want on your fresh build is a hot spot or impeded coolant flow.

"Make Me Bad"
Adobe Acrobat Reader 4.0
Vader is offline vBGarage Page   Reply With Quote
Old 10-24-2000, 12:21 AM   #3
Supreme Member
Join Date: Sep 2000
Location: USA
Posts: 1,057

Classifieds Rating: (0)

You've got a pair of the original camel hump heads found on 1961 -1966 iron (most noted for being on the 1962 "Fuelie" Vette). They were produced in both the small and large valve versions. The intake runner is 155 - 158cc and if stock does not move a lot of air. The old 461 heads have the "low" spark plug location and therefor do not make them a good candidate for "pop up" or domed pistons,,, especially if the heads have been milled.

The following link gives some flow data for a set of "462" heads,,, which were patterned after the 461 heads,, except GM raised the spark plug location slightly and relieved the quench area behind the plug a little. I would expect the 461s to have similar flow numbers though.

Good luck!!!!!

BadSS is offline vBGarage Page   Reply With Quote
Old 10-24-2000, 12:45 AM   #4
AlkyIROC's Avatar
Join Date: Jul 1999
Location: 51N 114W, 3500'
Posts: 15,890
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86

Classifieds Rating: (0)

461 castings typically have 165cc intake ports. These were used mostly by SuperStock class because of the small compustion chamber and the large ports and a unported head rule.

Even open chamber heavy casting smog heads such as 997's flow through 160cc ports.

Dart heads are better right out of the box. S/R Torquers are 171 and Sportsman's are 200cc

Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car and knocking on the SuperPro ET class
383 stroker (carbed) with double hump cast iron heads and pump gas
LS6 Big Block buildup now in progress

Best results before the engine blew up
Best ET on a time slip: 11.857
Best corrected ET: 11.163
Best MPH on a time slip: 117.87
Best corrected MPH: 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!

Member of the Calgary Drag Racing Association
AlkyIROC is offline vBGarage Page   Reply With Quote
Old 10-25-2000, 02:21 AM   #5
Supreme Member
Join Date: Sep 2000
Location: USA
Posts: 1,057

Classifieds Rating: (0)

Well the link I posted above got 156cc out of the 462's they tested and I've only seen one totally stock set of 461s and we got 155 cc for them,, so I sure can not agrue the point on one or two sets of heads. However, I did check and see that David Vizard qoutes 158 - 160 cc for the standard 461 runner size and mentions the 461-X,, that I had forgot about - They have 175cc runners - nice!!

For sure the SR will flow better than the 461s and so will a set of Vortecs. Both of which could cost less than refurbishing the old 461s - In an apples to apples comparison.
BadSS is offline vBGarage Page   Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
More HP on a budget gta90 TPI 40 09-15-2015 05:00 PM
[MN] Sbc trick flow 500 hp kit/327 wiseco pistons Mickeyruder Engine/Drivetrain/Suspension Parts for Sale 3 09-02-2015 03:45 PM
Easiest, cheapest tpi swap for 88 truck Keith5 DFI and ECM 2 08-27-2015 05:37 PM
carb to tpi questions regarding my situation theurge TPI 7 08-21-2015 01:46 PM
[MD] 1990 Trans Am drag/bracket car with trailer Dialed_In Firebirds for Sale 2 08-20-2015 02:45 PM

Go Back   Third Generation F-Body Message Boards > Tech Boards > Tech / General Engine

202, 3782461, 383, 461, 461x, 462, data, flow, heads, hp, numbers, pop, sbc, sportsman, stroker, valve

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 06:48 PM.

All content copyright 1997 - 2014 ThirdGen.org. All rights reserved. No part of this website may be reproduced without the expressed, documented, and written consent of ThirdGen.org's Administrators.