Low Riser Porting

[Marx427]

Hey all, new here and this is my second attempt at my first question post.   I own a 65 427 4 speed Galaxie. The engine has all the right stuff, C8JE block,  4.25x4.125 Scat rotating assembly, Crane roller lifters, Dove rockers on Precision Oil supports, Smiths rods and buttoned up with 8qt. Canton pan.

My one weak point is my heads, which I plan to replace with aluminum's sometime in the future.
Until then I'm running C4AE-Gs  with 427 Low riser/CJ valves with a little pocket porting and valve relieving.

My question is how much can I gain by an aggressive porting job on iron Low Riser ports?

My idea was to have an engine builder friend do a port job on one of each port then finish the rest myself copying his work. I have extensive  experience with grinders from my manufacturing background, but have never applied it to head porting.

I have 3 sets of FE heads.....another set of C4AEs,  one of C6AE-Rs and a set of 58 Edsels with machined chambers that appear to have plenty of space for 2.15 int and 1.65 ex valves.

Any ideas will be appreciated. Thanks,  Mark.

[jayb]

What intake are you running?  Is it the medium riser 2X4 manifold that came on 65 427 Galaxies?  If so, I think you can pick up a whole bunch (30+ HP) with a good porting job on the iron heads.  That manifold will support a lot of horsepower.

If that is not your intake, what manifold are you running?  The wrong manifold will dampen head porting gains...

[Marx427]

Hi Jay,  I'm running the Blue Thunder 2x4 Medium Riser style with matched  Low Riser ports and 600 BJ and BK Holley carbs right now.

But I also own..... a C7AE  PI,   an Edlelbrock F-427 , Holley street Dominator, Offy Port O Sonic ....
and a     352  Hi   Po     in    a    tree........

So,  I think Ive got all the intake bases covered.......my cam is a Snyder custom grind hydraulic roller  with 528/528 lift and 284/284 adv duration  with 108 degrees separation.

My exhausts are 65 long iron headers  and it Dynoed at  435 HP at  5600  with 500 ft lbs tq  at 3500......although Im not sure of the accuracy of those numbers since the stroke was entered as 3.98  when it's actually 4.125.........

I guess what I'd like to know is how much more can I expect from from max effort Low Risers and which would you chose to use  C4AEs,    C6AE-Rs   or  the 58 EDCs with machined chambers?

Thanks,   Mark

[jayb]

That Blue Thunder 2X4 is a good intake.  Let's see a picture of that 352 HiPo in the tree 

I think either the C4 or C6 heads will give you about the same results if they are equivalently ported.  With that cam, though, I'm not sure how much power you will get from the porting job.  You might think about upgrading the cam to a little stouter grind when you put on the ported heads.  435 HP for that combination sounds about right with the heads and cam, but a porting job and a bigger cam will make a huge difference on that engine.  If I had to guess, I'd say you might get 20 HP out of the porting effort, but you could get another 45-50 if you upgraded the cam at the same time, to something like a Comp 292S or better yet a mild roller.

[Marx427]

Thanks for the info Jay.  The cam I'm running now is a mild roller......my builder and I decided to  concentrate on Low and mid range torque which it delivers big time,  making 472 ft lbs at 2,500 and peaking at 500 at 3,500. 
The grind is from  Dave Tatum,  my engine guy.........he's a flat head guru now days, but worked with Jack Roush among others at ford in the 60s on the Tunnel Port projects, both big and small block which evolved into the Boss 302. 

 I'm kind of thinking he's made my FE run like a giant flat head ...........lot's of low end torque!  It works well in that 2 ton Galaxie.

Thanks again,  Mark.

[CDXXVII]

Mark, Just wondering if the car is an R-code.
When porting, is there a way know how much wall is left before you hit water?
I would assume if you break through the head is pretty much junk.

[Marx427]

No the Galaxie isn't an original 427 car..........It was an L code.......240 six with split shift overdrive 3 speed.   
So I guess what Ive got is a clone.......doing my best to make it look like the original 427 Galaxie that I fell in love with in 1965 watching Stock Car (Nascar) Racing with my dad .

The long range plan is to put High Riser heads on it  if I can score an original 2 plane 2x4 intake.
I need a good reason to put a  T-Bolt style hood on it.

The car is a 500 , not an XL ,   bench seat w/4 speed and original 65 cast iron long headers. ..... black/black  ...skinny steelies ......Cherry bombs ...
                                                                                           
                                                                                             
 AND..... a  shrunken head hanging from the mirror.........  60's style

[CDXXVII]

The 240 is "V".
Do you have the Hi Riser heads already?What is out there for Hi Risers? Dove? Pond?

[Marx427]

Yes you're right , it is...er..was.....is a V code.   And no,  I won't buy the heads till I score a Factory High Riser intake. Been in a couple bidding wars on e-bay but wasn't quick enough.

Blue Thunder has high risers heads but I think they're aimed mostly at hard core racers....
Dove seems to have more than one type of high riser or maybe several........there isn't a lot of info out there about either Blues or Doves.....especially on their own sights...and I'm afraid to call them for fear I'd be talked into something I can't afford now....

[hotrodfeguy]

On the intake side it's not that big of a deal if you do happen to poke a small hole it can be brazed on the intake sides. But I use a sonic tester now to do my porting with iron. The exhaust gasses are going to get out and are a little less criticle as how much needs to come out. The new roller grinds out there are much improved and will gain you alot of power. Also remember that when you stroke an engine it will want more cam/duration per the same RPM to "feed" the volume gained by the enlarged stroke. The G/R heads can be widend out to about the MR port size just DO NOT mess with the bottom 1/4 of the ports on the intake side. The floors will disrupt things if played with. here is a C1AE 6090-A port but same thing.

http://i146.photobucket.com/albums/r264/hotrodfeguy/intake.jpg

[My427stang]

I am not sure where you are from, but I had Les Schmader in PA port my D2 heads. He did a very nice job and I tend to be very fussy

He got 277 cfm out of them, and that is starting with a 200-210 cfm port, but I have seen low risers that he got closer to 290, that's a good performing head.  35+ cfm more than stock

The good thing was the price, 550 for his full port and valve job, 60 bucks return shipping for me.   In my case I supplied springs, valves, etc, but I understand he has some good prices on parts too.

[Marx427]

Thanks for all the responses.  It seems like it will be well  worth the effort.

 And from   My427stangs   post it looks like the later post 66 heads flow fairly well too and may match my current cam specs better than the Low Riser ports..........already have a set
of C8AE-Hs.......maybe also worth a try? 

[My427stang]

The C8AE-H flow like crap without work to them LOL

200 cfm is good for maybe 450 hp in a perfect combo?  That's a bit of a wag, as a second issue, they are hard to find headers for.

I just brought up that a good porter can do good things, and better things with the early heads.

I wouldnt run later heads unless I had a requirement to run that exhaust port.  Which I did with the truck headers

[Marx427]

Did you see the post from the guy with the 428 inch /406 6V clone?  He's using C8AE-Hs with CJ valves and no other work and made 500lbs and 415hp. 
It was his torque curve that got my attention ...except his  numbers being a little lower than my 468s the curve is very similar...
Was just thinking it would be fun to try to increase my low end torque even more.......just because.

I'm not necessarily always looking for peak Tq/Hp numbers.

Ive reached a point in life where sometimes its just fun to say "Well, that didn't work...just like I thought it wouldn't."

[My427stang]

I get it, but you have to flow enough air to make power.  Thats why we worked so hard on my D2s, they are basically med riser copies ont he intake side now, but with 2.09/1.67 undercut stem valves, but work on my truck with the lower exhaust port for the headers.

If you dont mine working them hard, C6's would work OK, but you are starting 40 cfm lower in airflow.  In my opinion the intake manifold choice makes a MUCH bigger difference in overall port behavior.  I would much rather run a med riser sized intake manifold port to gain port velocity and torque, woth a better flowing head.

The intake is a much greater percentage of overall intake runner volume than a short intake port in the head.

Matter of fact, within reason, I'd much rather shorten a cam and run a good port than the other way around

Are you running headers?

If  I was searching for more low end torque,I'd keep the med riser intake, port the heck out of the C4 heads, and advance the cam as far as I could with whatever compression I am running.  That'd bring power up on the whole curve and advancing the cam would make it a little more responsive down low.