Brought to you in part by:

Great deals on auto restoration supplies!

.


JC Whitney clearance center!

  Mustangsandmore Forums
  Ford Racing
  Had my Boss 302 heads on a flowbench...

Post New Topic  Post A Reply
profile | register | preferences | faq | search

next newest topic | next oldest topic
Author Topic:   Had my Boss 302 heads on a flowbench...
Rustang
Gearhead

Posts: 733
From: Clarion PA
Registered: Nov 2000

posted 07-22-2001 05:21 PM     Click Here to See the Profile for Rustang   Click Here to Email Rustang     Edit/Delete Message   Reply w/Quote
I took my intake manifold to a local head porter this week to have it straightened out. (I butchered it when I ported it!) I left one of my heads there for him to match to the intake. Anyhow, he stuck the head on the Superflow and got the following:

Intake, starting at .100 lift to .700:
70, 147, 213, 265, 300, 310, 321
Exhaust at the same lift points:
54, 95, 136, 171, 195, 200, 200
I was very surprised on the intake numbers! Especially since they have the Roush spacers in them. I guess I just got lucky since I ported them myself. The guy that checked them was suprised too. He double checked everything and reran the test and came up with the same numbers. So now I know that I have enough cylinder head (there's still some left in the exhaust though) and I'm going to concentrate on other areas.

IP: Logged

Mpcoluv
Gearhead

Posts: 1278
From: Charlotte NC usa
Registered: Apr 2001

posted 07-22-2001 08:10 PM     Click Here to See the Profile for Mpcoluv   Click Here to Email Mpcoluv     Edit/Delete Message   Reply w/Quote
Those numbers look great.
Did you notice any improvement in low end due to the Roush inserts?
Can you post any photos of the heads?

IP: Logged

kid vishus
Gearhead

Posts: 6098
From: middle of NC
Registered: Oct 2000

posted 07-22-2001 08:39 PM     Click Here to See the Profile for kid vishus   Click Here to Email kid vishus     Edit/Delete Message   Reply w/Quote
Those numbers look good.

And you are right, there is more to be had in the exhaust ports. My 4v C heads went 228 cfm at .700 lift on the exhuast with my home port job. Your intake numbers are better than mine in the upper lift range, those Roush plates must help.
Here's mine just for comparison sake

intake .100 to .700
74,155,228,275,281,290,305

exhaust .100 to .700
50,93,141,177,201,216,228

IP: Logged

Rustang
Gearhead

Posts: 733
From: Clarion PA
Registered: Nov 2000

posted 07-22-2001 09:18 PM     Click Here to See the Profile for Rustang   Click Here to Email Rustang     Edit/Delete Message   Reply w/Quote
Actually, Kid, I read one of your posts from the Cleveland archives and ported the exhausts based on what you described! I've completed these mods on one head (NOT the one at the porters. All it had done was bowl work, trimmed valve guide, and good valve job)
Anyhow, I raised the port not quite 1/8", straightened out around the head bolt, removed the small emmissions hump, and did a little clean up around the upper left header bolt. I then polished it up a little. Your 228 CFM is impressive. One other thing that I hope helps out low lift is I smoothed the transition of both valves in the combustion chamber. Those big machined recesses in the chambers looked like they'd be terrible for flow in the seat to chamber transition( I think the chambers were machined this way from the factory).
I'd like to reflow them now, but times a waistin' .... GOTTA GO!!!!!
Oh, and MP, I'll try to get some pictures up in the next couple of days.

------------------

IP: Logged

Rustang
Gearhead

Posts: 733
From: Clarion PA
Registered: Nov 2000

posted 07-22-2001 09:25 PM     Click Here to See the Profile for Rustang   Click Here to Email Rustang     Edit/Delete Message   Reply w/Quote
Kid, I just thought of something. How 'bout I trade you my intake port for your exhaust port?

------------------

IP: Logged

bluestreek
Gearhead

Posts: 1724
From: Athens,GA
Registered: Jul 2001

posted 07-22-2001 09:42 PM     Click Here to See the Profile for bluestreek   Click Here to Email bluestreek     Edit/Delete Message   Reply w/Quote
Great numbers on you intake flow!!
The exhaust side of the Cleveland style head is very restrictive.. They were designed strictly for a turndown ehaust manifold to allow for tight engine bay clearances..
You must work on getting more action at the roof of the exhaust port by smoothing out any obstructons and bumps and widening it as much as headers will allow, and smoothing down the short turn radius.. Also use headers that follow the roof of the port as long as possible.. The lower 1/3 of the exhaust port is useless at high rpms.. It's been a few years since I played with a Cleveland but I remember that they are totally different than any other animal..

If only FORD had spent a couple more years on it??

[This message has been edited by bluestreek (edited 07-22-2001).]

IP: Logged

kid vishus
Gearhead

Posts: 6098
From: middle of NC
Registered: Oct 2000

posted 07-22-2001 09:48 PM     Click Here to See the Profile for kid vishus   Click Here to Email kid vishus     Edit/Delete Message   Reply w/Quote
WOW
With just bowl work and trimming the guide boss down some and knocking the bump down in the roof, my exhaust only went 185 cfm at .700 lift. I picked the rest up with the port work later.

IP: Logged

bluestreek
Gearhead

Posts: 1724
From: Athens,GA
Registered: Jul 2001

posted 07-22-2001 09:54 PM     Click Here to See the Profile for bluestreek   Click Here to Email bluestreek     Edit/Delete Message   Reply w/Quote
Kid,
Looking at your exhaust numbers, I'd say you did your homework..

IP: Logged

Rustang
Gearhead

Posts: 733
From: Clarion PA
Registered: Nov 2000

posted 07-22-2001 10:34 PM     Click Here to See the Profile for Rustang   Click Here to Email Rustang     Edit/Delete Message   Reply w/Quote
Kid, am I understanding you right in your last post that you went from 185 to 228cfm with the roof work and stuff I described? If I read that right, I could possibly pick up that much over my 200cfm!?!

------------------

IP: Logged

kid vishus
Gearhead

Posts: 6098
From: middle of NC
Registered: Oct 2000

posted 07-22-2001 10:39 PM     Click Here to See the Profile for kid vishus   Click Here to Email kid vishus     Edit/Delete Message   Reply w/Quote
Yes I did. I did work on the short turn a little more the second go around. I was a little leary of grinding to much off the first time I worked on them so there was still room for improvement. I widened the port at the transition area into the bowl a bunch too.
I wouldnt be suprised if you picked up 30 cfm. It sounds like your intial port work was better than mine and that may have some to do with why I picked up that much the second time.

IP: Logged

bluestreek
Gearhead

Posts: 1724
From: Athens,GA
Registered: Jul 2001

posted 07-22-2001 11:56 PM     Click Here to See the Profile for bluestreek   Click Here to Email bluestreek     Edit/Delete Message   Reply w/Quote

We used to bore Clevelands .040 over just to get less shrouding on the valves..
Believe it or not, it helped.. Trying to keep intake velocity up and getting it through the chamber is the name of the game.. A Cleveland can easily bog itself on the intake port if you ain't careful with the chamber, exhaust port, and the duration of the intake..

That's all I'm gonna say..

IP: Logged

Clevo377
Gearhead

Posts: 312
From: Blackburn, Victoria, Australia
Registered: Nov 2000

posted 07-23-2001 07:24 AM     Click Here to See the Profile for Clevo377   Click Here to Email Clevo377     Edit/Delete Message   Reply w/Quote
Bluestreek, by all means start a new post. I'm slap bang in the middle of porting my 4V's. I've had the lower portions of both intake and exhaust welded up, as well as the top(outside) of the exhaust. I'm interested to hear about port shape and short side radius (how much of a radius) At present I have'nt shortened the straight shot to the back of the valve, just put a nice curve from the new material to the existing short side (I hope I've explained this okay)

Am a little apprehensive about the whole deal, but hey, you don't know unless you give it a go!!

Paul

IP: Logged

jkilroy
Gearhead

Posts: 1808
From: Vicksburg, MS
Registered: Dec 99

posted 07-23-2001 08:43 AM     Click Here to See the Profile for jkilroy   Click Here to Email jkilroy     Edit/Delete Message   Reply w/Quote
All I have to say is DAMN! Those are some impressive numbers, we're talking entry level big block numbers! No wonder BOSS 302's don't have any bottom end!

------------------
Jay Kilroy
68' Fastback GT 390
"No such thing as a cam thats too big"

IP: Logged

bluestreek
Gearhead

Posts: 1724
From: Athens,GA
Registered: Jul 2001

posted 07-23-2001 11:42 PM     Click Here to See the Profile for bluestreek   Click Here to Email bluestreek     Edit/Delete Message   Reply w/Quote
Here's my ideas on head porting:
All you need to do is try get anything out of the way that impedes a straight shot to the valves or gets in the way of the flow.. the less turn the port has to make, the better..Larger ports aren't always better if the transition is too quick into the short turn radius..Try to maintain a balanced port instead of a large port and be careful of the water jackets..A little porting in the right areas is ussually better than a lot of porting..Keeping the velocity up in your ports is very important for quick revs and good fuel mixture.. Start off small and get the feel of it, before doing any heavy grinding.. It's a long tedious job, but can yeild good results if you take yourt time..Here's some things to pay attention to other than the ports.

1. Make sure transition from valve to combustion chamber is smooth without any bumps or edges in the way.(shrouding)
2. Smooth down spark plug boss in the chamber.
3. Pocket beneath the valve seat should be perfectly even with the lower angle on the valve seat.
4. NO sharp edges or bumps that arent necessary in the port, chamber, and piston dome..
4. Pay close attention to piston dome detail and try to make it smooth and "go with the flow". (often overlooked)
5. Make sure valve sits as high in the seat as possible..(very important for good low lift numbers and torque)
6. Polish the bottom side of the valve to get a good smooth flow into the chamber..
7. Port match all gaskets and maniflods to the head ports as perfectly as possible..Any transitions you have to make should be at least 1"..

Here's a little drawing for Cleveland heads that I threw together very quickly, but may help you get an idea..There's no attention to detail, so don't take it too seriously.. Porting is a very personal thing, and everyone has different ideas as to what works best for them..

Have fun!!

http://www.picturelist.net/Images/dbhard/cleveport.JPG

[This message has been edited by bluestreek (edited 07-24-2001).]

IP: Logged

All times are ET (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | Mustangsandmore Front Page

Copyright 2005, Steve LaRiviere. All Rights Reserved.


Ultimate Bulletin Board 5.47d

Amazon Honor System Click Here to Pay Learn More

[Build a free Mustangsandmore.ws Home Page!]

[Posting Pictures]

[About M&M][Acronyms][Calendar][Chat][Classifieds] [Members' Pics]

[M&M Conventions] [M&M Mug Shots]

[ Mustangsandmore.com Bookstore] [ Smokin' Fords] [Tech Articles]