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289 head porting questain

Discussion in 'The Hokey Ass Message Board' started by metalman, Nov 29, 2013.

  1. metalman
    Joined: Dec 30, 2006
    Posts: 3,280

    metalman
    Member

    My boy is doing a little port work on the 289 he's building for his Ranchero.
    Been 30 years since I ported a set of sbf heads and just want to verify that he can cut this whole lump out of the exhaust port. If I remember right it's for an air pump hookup and we don't need it. I don't remember having a hole in it before but the hole seems to go no where.
    289head.jpg
    I don't want to tell him to cut it out and have him ruin the head cause I told him wrong!
     
  2. You can remove the hump and it helps the flow numbers.
    Dont get to agressive, the water jacket is just above that.
    Blend it to the roof and thats all thats needed.
    Matt
     
  3. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    ^^yup, x2. In my experience, you can remove maybe another 1/8" from the roof of the exhaust port after you have removed the thermal-actor boss, but thats pushing it, there IS water up there. If you are an experienced head porter, you can tell when you are getting thin, as while you are cutting, you can use your fingertip to feel hot spots on the surface of the port where you are getting thin, but I cant recommend this to someone who's inexperienced, as it requires a LOT of feel. These heads are also on the thin side on the inner wall just as you approach the short turn, so if you are really getting after it, you want to use some caution there.
    If he is going to bigger valves, his easiest gains will come in laying the chamber wall back to the bore around the intake valve curtain.
     
  4. luke13
    Joined: Oct 25, 2013
    Posts: 381

    luke13
    Member

    be real carefull to allow for core shift in the different ports, thats what makes the port walls thicker or thinner when theyre cast in the foundry, if youve got some WREAKED heads you can cut one up in the bandsaw to have a look at the average wall thickness. plus its quite interesting to do just for shits an giggles.. but yeah get rid of it, if you were an excapeing exhaust gas fume you wouldnt want to hit that would ya? id spend most of my time on the valve guide boss and cleaning up fore and aft of the valve seat and a light polish up to the guide.
     
    Last edited: Nov 29, 2013

  5. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    How is cutting up a head other than the one you are working on going to help you detect core shift?
     
  6. luke13
    Joined: Oct 25, 2013
    Posts: 381

    luke13
    Member

    to get an idea of average wall thicknesses, and to help establish how much much you can safely remove from certain areas, proberbly more helpfull if your planning some radical port opening up. but it is pretty interesting to look at a sliced up head, its amazing just how thin the port walls are in some areas.
     
  7. Yep, X 2. More than that and the risk outweighs the gain if any. If you're trying to build power, the early heads won't offer much even when ported, better to find a set of 351W heads. The rare '69 4V heads are best, but the '70-75 2V heads will give a nice gain and aren't as hard to find anymore as the serious guys have switched to aluminum heads. If hogging the ports, don't bother with the bottom of the exhaust, limit changes to the sides/top.
     
  8. luke13
    Joined: Oct 25, 2013
    Posts: 381

    luke13
    Member

    merc cruiser made some real good heads for the sbf too.after a small amount of reasearch i put a set on my 302 windsor and that thing went really well pulling a 56 customline, after people said they wouldnt work well on a street application. worth a look into and theyre usually real cheap too.
     
  9. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    As far as "the risk outwieghs the gain if any" thats hogwash. But seeing those gains is beyond the skills of a first timer. I have a pair of D0OZ's and a virgin pair of C9OZ's, if you really go nuts, you can see 240/250 CFM, but its sure no job for a beginner, and you will not attain those numbers from 351W heads without a flow bench. Honestly, I dont know if I would bother seeking them out if I didn't already have them, there are later factory heads that head for head, will do as well or better as far as your basic home-brew pocket port.
    Its like the old saw about 452 Mopar heads out-performing 906's. Its not really true, but the level of skill it takes to make the changes required to get a set of ported 906's to outflow a set of ported 452's exceeds most guys abilities.
     
  10. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    Yes, but how does that help you detect core shift? Core shift varies from casting to casting, whether its blocks or heads. Thats WHY its called core shift.
     
  11. luke13
    Joined: Oct 25, 2013
    Posts: 381

    luke13
    Member

    yes thats true but it will only shift so far before it becomes a factory reject.. it just gives you a perspective of areas that are normally very thin anyway so as to allow for core shift by say a few millimeters, so if you know that around the guideboss has alot of material but the short turn radius and side walls are less on material normally, then you know you have take real care on the short turn and side walls cause theyre thin anyway but if theres core shift of say 1 1/2mm then you know you have to take real care cause itll be real thin in those given areas.or you need to find another set of heads with better tollerances.
     
  12. metalman
    Joined: Dec 30, 2006
    Posts: 3,280

    metalman
    Member

    Thermo-actor boss, ok, guess I now know what it's called and thanks for verifying he can cut them out. Before this gets into a discussion on whether it's worth it or not, not a point here. Like I said it's been 30 years since I've ported a set of stock sbf heads since I personally would rather buy a set of the new heads available today that will flow better out of the box (+ spending hours with a die grinder isn't my favorite pass time!) . My boy however is building this on a very tight budget and porting these will only cost him time which he has more of then $$. If he gains a couple hp, fine, if nothing else he's gaining experience so all is good!
    FWIW I have a set of fresh later 351 heads here we were planning on using but the machine shop said the loss of compression would offset any gains by using them without going to expensive pistons, here again trying to get the most from a minimum budget.
     
  13. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    I'm sure I spelt that wrong, but I cant seem to think of the right spelling right now...:eek:

    I totally agree that doing some basic head porting is VERY worthwhile, and a good learning experience. This BULLSHIT that was started by the magazines trying to shill aftermarket heads for their advertisers have become part of what I call the car craft syndrome, where BS printed in the magazines becomes accepted as "fact" after enough guys trying to sound like experts repeat what they read in the magazines.
     
  14. That was my point; a first-timer doing a home porting job isn't going to get much if any in the way of meaningful results if doing more than just knocking the thermactor (correct spelling...:)) boss out of there. The 351 heads are an 'upgrade' over 289/302 parts, but given the availability of better heads these days not really worth the effort. A set of good used GT40 heads will probably be cheaper than a rebuild on any early iron heads....
     
  15. luke13
    Joined: Oct 25, 2013
    Posts: 381

    luke13
    Member

    george is right a basic clean up with the stock heads will work wonders specaily for flow at low lift heights, a quick clean up, few minutes on each port to remove machining lips and cast dags etc will make a lil 289 nice and responsive, good motor to start with, you have to becarefull with some of those 351 heads as they were real dogs as far as flow is concerned.
     
  16. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    what I am suggesting is that rather than hunting up a set of early 351W heads to port, round up a set of used GT40s or world products heads and port those.
    If you already have the 351W heads, they are well worth doing. 250cfm is as good or slightly better than a set of Performer RPM's will do out of the box, if you have the skills, its well worth doing the windsors. But only if you have the skills.
    I do think doing a bit of mild pocket porting on his 289 heads is well worth it, especially if he adds a set of 1.84 intakes to the mix, and lays back the chamber wall. He should be able to get 210/220 cfm if he is careful and does his homework.
     
  17. George, I'm agreeing with you..... ;)

    I ran the 351 heads 'back in the day' when they were the only 'upgrade' head for the 289/302 and with a bit of work (forearmed with a bit of knowledge) could perform quite well. One thing I disliked was you needed to install screw-in studs and guideplates or you had to run the rail rockers. But these days, unless I had a set on the shelf or got them for next to nothing, by the time you do all the mods it's easier/cheaper usually to use a modern set of heads....
     
  18. luke13
    Joined: Oct 25, 2013
    Posts: 381

    luke13
    Member

    yes now that you mention it the merc cruiser heads i used on the 302 were based on some sort of pre smog 351w heads.
     
  19. Yep, a lot of the 302 marine motors Ford sold came from the factory with the 'good' 351 heads, usually with hardened valves and seats too. As well as other interesting bits like a 3-bolt damper with the late 50 oz balance and some trick oil pans.
     
  20. JeffB2
    Joined: Dec 18, 2006
    Posts: 8,862

    JeffB2
    Member
    from Phoenix,AZ

    Since he is doing a budget build buy this:http://product.half.ebay.com/_W0QQprZ592442 lots of good info like this:http://product.half.ebay.com/_W0QQprZ592442 You can probably find a set of C5AE's without the thermo bumps and swap to these valves:http://www.ebay.com/itm/1-84-1-5-In...Parts_Accessories&hash=item27cd701248&vxp=mtr That way you will still have enough meat in the stock seats in most cases and the compression benefit of the C5AE's.You might pick up a few ideas here also:http://www.youtube.com/watch?v=bF0Rwh2KIlI
     
    Last edited: Nov 29, 2013
  21. powrshftr
    Joined: Mar 29, 2013
    Posts: 4,550

    powrshftr
    Member

    I know lots of guys are going to have an issue with this,but I have done over a dozen sets of 289/302/351W heads for myself and others,some used in turbocharged Windsor street/strip cars with zero durability issues....
    Anyhow,on the exhaust side of a small Ford you can actually grind the valve guide completely out,making the roof of the port a smooth,continuous,flowing surface with no big,knobby restriction to airflow hanging in the way.
    Just be careful not to get too aggressive and dig in instead of just smoothing out...
    All the sets I've done have been in use for years with no failures or cracking.

    Also,when you do the intake side,I wouldn't waste time porting to the Fel-Pro 1252 gasket,skip right over it and go straight to the 1260 gasket,as it will provide a nice improvement.

    Just go slow til you get comfortable,cause you can always go back and remove more,but you can't use wishful thinking to put more iron back into that ragged hole in the water jacket...!;)

    If you're on a budget,George is right on the money about installing Windsor size 1.84" intake valves,and while you're at it,see if you can get the 1.54's from the same motor.

    Keep us posted on your progress,and don't be afraid to ask questions as you go;these guys are a great bunch of guys who are always quick to help out somebody in need of assistance or guidance.

    Above all: Have fun with it!:)

    Scott
     
  22. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    No arguments from me, I agree, the entire guide boss can go, although I think its just as effective to reduce it in size, teardrop it and grind a vane in the backside, and it looks a little nicer.
    If you choose to keep the end of the guide, best tool in around the guide is a 1/4 ball cutter, in my experience.
     
  23. powrshftr
    Joined: Mar 29, 2013
    Posts: 4,550

    powrshftr
    Member

    I knew you would be onboard as a Ford guy George:)
    I figured some of the guys who are used to working with sbc's would get a little choked up about it though...

    Scott


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  24. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    Oh GOD! Please! I know I own a couple, but calling me a "Ford guy" is uncalled for...:p
     
  25. powrshftr
    Joined: Mar 29, 2013
    Posts: 4,550

    powrshftr
    Member

    Lmao!
    At least Ford has a racing heritage....
    It's not like I called you an "import guy" or something...;)

    I would be fully expecting to receive an envelope full of anthrax,or a package that makes ticking sounds,or something' like that......:D

    Ps:I'm going to be starting a SBF porting thread over Christmas,and I just recently picked up a single,orphaned E7 5.0L head to whittle on and shoot a few pictures....
    Pretty much everything done to the Ford head will be universal,and will transfer over to Chevys,but the Fords really need some love in specific areas,so I'm gonna put emphasis on that.
    I have a set of 555 casting early Hemi heads that I will do after that.

    And it is EXACTLY like George said:Magazines stay in business by hawking their advertizers' parts,so that heavily influenced the boom of aftermarket heads.You can still make a SHITLOAD of power with stock castings that you port at home!

    Scott


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  26. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    I'll be looking forward to your porting threads. Its funny, they hawk those E******** *** heads like they are the second coming of christ, but if you actually look at the flow numbers, most of them move about the same amount of air as the corresponding factory casting with a clean-up and a good pocket-port, most of the parts on the cheaper aftermarket heads are junk, and the guides are usually too tight out of the box, so if you are someone that actually checks this stuff and gives a shit, they end up going to the machine shop anyway.
    And if you cut the spring pads and stud bosses on the iron heads yourself and just farm out the guides and valve job, the home-ported factory castings are a shitload less money. The AFR's are another story, most of them really move some air, but they are serious $$$ too.
     
  27. I've got a set of the very first Trick Flow 'twisted wedge' SBF heads (bought at the 'introductory' price of about $750 IIRC) that have been under my work bench in the box ever since. Never used (my now-X always managed to pull some sort of financial catastrophe right at the point I was ready to build an engine), I've heard these have 'issues' with the iron valve guides and roller rockers were a must for guide life. Of course, getting 'real world' info from the mags is a pipe dream, anybody have any comments on these? Hate to pitch them, but if they're a poor choice, it is what it is....
     
  28. powrshftr
    Joined: Mar 29, 2013
    Posts: 4,550

    powrshftr
    Member

    I agree.Most of the aftermarket stuff doesn't really shine until tuned up with basic detail work that should have already been done.
    And those AFR heads can definitely take a motor from Zero to Hero in a hurry.

    I just hope I can help out some guys with this porting thread,to help them get their feet wet,without feeling too lost or intimidated like some of us did when we were learning this stuff.
    Not everybody is lucky enough to have talented,patient,generous mentors like I did.
    We have a local guy,"Fast Freddy",who sorta took me under his wing when I was younger and gave me a pretty comprehensive lesson on porting.
    I owe him big time.

    Scott


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  29. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    I had Bob Crosbie, That man had so much talent, and in so many different areas. Hell of an engine builder, master fabricator, 1st rate chassis builder, he could do it all. He died of luekemia in his forties, a real shame.
    I learned a HELL of a lot from him, but I also learned a lot by building my own flowbench and using it when I was still in my late teens. I used the info in the landmark Car Craft series of articles from around '76/'77.
    I keep saying it on here, but we owe so much of where we are today to Harold Bettes. His idea of bringing flow benches to the masses is the sole reason why you can bolt together a streetable 450hp sb today, regardless of what heads you use to do it. Without the proliferation of flow benches in the seventies and eighties, there just wouldn't be the widespread knowledge on HOW to port heads that really work, and there wouldn't be the literally dozens of companies out there making aftermarket heads. It brought us out of the dark ages.
    Theres a fundamental difference between AFR and you know who, AFR started out as a company that ported existing iron heads, and became famous for it, long before they ever started making aftermarket heads. They came at the deal from a different place.
     
  30. powrshftr
    Joined: Mar 29, 2013
    Posts: 4,550

    powrshftr
    Member

    That's really cool that you had such a talented and skilled guy to get you started George,and I'm truly sorry that he died so young.
    I re- read the article where AFR worked over a set of C9 Windsor heads a while ago....I believe it was in Car Craft.I know it was by Marlan Davis anyway.He's always been a no-bullshit,meat and potatoes tech guy.
    That article really showcased them as real thinkers,not just some hillbillies hogging out ports til they hit water.
    I think I should upload that article and attach it to the porting thread,as the photography was quite good in it , as far as giving an accurate representation of what the ports look like.Its tougher to do than you think...try it sometime...!lol!

    Scott


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