Sorry for the pretty basic question, but I am still learning which directions to go. If you port and polish the heads, is there anything else you NEED to do to the block/intake manifold/etc afterwards? Or is this just something you can do to the heads? Also what are the benefits of having them done and doing them yourself? Difficult? Any help would be great guys thanks!

 

You didn't mention what year model etc so can't give specifics. I haven't hot rodded a Ford anyway, so can only give general advice here.

I did this way back in the 70s on a Dodge Wedge, so my experience is antique and possibly obsolete... It takes a long time with stones and a hand drill, so get the proper air tool and proper stones and if they sell templates for the port profile get them. There are web sites that have how tos and sell the proper stones and air tools, I forget the web address, sorry.

The benefit is not much considering how much work it takes. But racers struggle for a couple horses here, a few there so for them it makes sense. I would only do it on a street engine if I just enjoyed playing with the engine. Rule of thumb was that you would get maybe 5% on a hot street engine. Porting and polishing work well for high RPM high air flow engines, for daily commuters it is almost in the class of chrome speed parts.

Maybe just port matching your intake and exhaust will be enough. To port match, just take a gasket and scribe the ports onto the surface of the head. Then grind out the metal to match the gasket outline and go into the ports maybe an inch or so. This is relatively safe and will give, SWAG, about 70% of the benefits of a full port job.

Contouring the inner passages and around the valve guides is tricky business. You can easily cut thru to water, that's bad. As mentioned earlier you might look into finding some templates. Templates are little cutouts(look like puzzle pieces) that are glued to sticks that you shove into the port as you are porting, to check to see if you are following the proper contours at the proper depth into the port. These templates make it easier and safer for a do it yourselfer to do this.

To do the job properly you would need a flow bench and knowledge about where the water jackets are, plus knowledge about how much and why to port. A professional will do a good job and know why and where to cut. But, they cost a lot of money since a proper port and polish takes a long time.

Polishing the exhaust is usually worthwhile, but it was found years ago that a little roughness in the intake helps the airflow. Too smooth an intake actually hurt performance.

You could also polish the combustion chamber to remove potential hot spots. Don't grind away here, or you will lower your compression ratio. Aslo put some beat up valves into the chamber to prevent you slipping and cutting a valve seat.

You can block off the heat ports but this will reduce the cold weather driveability. There are gasket kits that block off the heat ports.

If it was me, I would work on a better exhaust pipe set(CAT Back at least, headers better) and maybe a better intake manifold. Maybe a cam. Typically these three items give you the most bang for the buck. Getting into the engine would be my next step and or avoiding that, doing the heads.

Porting and Polishing is icing on the cake. It sounds cool to say your heads are ported and polished, but unless you are a serious racer, you can spend your time and money better on simple bolt ons.

Good Luck,

Jim Henderson

 

In regards to whether you should have a pro do them or do them yourself: There's a lot of little tricks to porting heads, these tend to be more critical on the intake than exhaust. This isn't to say the exhaust isn't important. Ford heads are restrictive on the exhaust ports and they need to be worked significantly for a high HP engine build. But for the intake, if you take off too much material in the wrong spot you can actually hurt the performance, drop fuel out of suspension, etc. You really need to know what you're doing with them to make it work efficiently. That being said, if I were interested in learning some porting techniques I would send a head to Scott at Reincarnation Automotive. I know he used to, and believe he still does port and polish one intake and one exhaust port and then run a flow test on it. Then he ships your head back to you with the flow numbers. You can look at where he's shaved the port, how he's shaped it, etc and just copy this on all the other intake/exhaust ports. It's a very time consuming process on iron heads.

One more thing I'll mention, which Jim covered more or less anyway, but if you don't use a cam that will increase the airflow the porting is pretty useless. Ported heads will give you the ability to move more air and create more power but only if you install a cam that will do so.

 

actually a budget port job such as scott j. does is good for about 25-40 rwh more and an increase in economy with nothing else being done but that.imo if i did anything i"d do that first b4 anything else.but from talking to Scott this will benefit the everyday driver or one used for towing as well as one for higher performance.fwiw older ford heads such as the D3 or DOVE heads are very restrictive like Ivan mention ,they are done making power at around 4500 due to the turbulence in the exhaust port.the biggest gains per time involved will come from porting.scotts budget port job on the exhaust doesnt look real pretty but wil boost a stock Dove exhaust flow from around 135 to around 185cfm.

 

Thanks for the replys guys, the heads are C8VE-E and go with a 1969 429. Looking to get a little bit extra outa a '56 f100. So this procedure is only done on the heads? and you need a cam that will take advantage of it? Am I understanding this correctly?

Thanks again for all the help, any other info would be appreciated.

 

Porting and polishing is mostly for the intake and exhaust ports on the heads. You can extend it into the manifolds if you like. It gives you a little more performance.

From what I have read way back, you can port match the exhaust so it makes a smooth transition from the head exhaust port to the manifold. The intake can be a little tricky.

Most carb intakes can be portmatched, BUT, there are a few aftermarket and maybe a few factory intakes that have a REQUIRED STEP or mismatch in the port transition to prevent intake reversion(the air/fuel stream backs up thru the intake and out the carb, take a look at the underside of an old style air filter can, the stain is reversion). You DO NOT want to grind out the step or port match the intake ports on these types of manifolds. I do not know which ones they are since it has been a long time since I read that. If you have an aftermarket intake I would study this issue more closely.

Most stock street engines won't really benefit from this, but a few that are horribly clogged up at the ports might get some gain. Until you are really pumping a lot of air most engines don't get a noticable gain. Cams, intake manifolds, exhaust systems, higher RPM etc increase air pumping, so porting starts to make sense.

As mentioned earlier, the rule of thumb back in the 70s when I ported and polished my engine, was you would get roughly about 20 hp more from an engine that had been modified with intake, cam and exhaust. That is not a lot when you are looking at an engine of about 400 cubes(my wedge was a 383 with .060 over). So do the other stuff first for most kick in the pants. You probably won't feel the difference with just porting and polishing.

Good Luck,

Jim Henderson

 

Need to check out Scott's website for a mear $25 he gives you complete instructions. After all that is what he does for a living. I don't have his web address handy this moment, but I sure someone on this board can.

 

Found Scott's site www.reincarnation-automotive.com

 

First off you have to understand that the iron BBF heads are all terrible with regard to exhaust port efficiency. This not only applies from the stand point of peak flow but also applies to the turbulent nature of the as cast ports. This applies to ALL iron ford heads even the iron CJ's.

This (turbulence) was by design to reduce emissions in conjunction with the thermactor's injected air.

The as cast D3VE exhaust ports begin to back up at about 3,500 RPM and are finished making usuable power in the low 4K range.

The belief that a stock (ish) build does not benefit from better flowing cylinder heads is completely false. The stock BBF heads are so bad that doing nothing more than taking the exhaust port from the stock flow of 129 cfm to an easy 180 cfm paired with some intake bowl clean up will consistantly show 25 to 40 RWHP and 8% increased fuel economy due to reduced pumping losses. This very thing was written about in the late 70's by Denny Wycoff of Cam Masters fame along with David Vizard.

The better flowing port passages will allow the combo to behave as if it has a more agressive camshaft, provided port velocity is maintained. Passage shape is critical for best results. Indiscriminately hogging out a passage usually does more harm than good in most cases although it is really hard to make a bbf exhaust port any worse than it is as cast.

The difference between a late model 200 HP 460 and a 325 hp combo is mild cylinder head porting, dual exhaust, recurved distributor and non retarded timing set. Add a mild cam and headers and you have another 50 to 75 hp.

Hope this clears up some misconceptions about the efficacy of port work as it applies to our BBF's.

 

Thank you Scott (The Mad Porter).
We often take for granted, the chance to get free advise from someone taking the time to try and help, who makes a living doing this very thing.

I have read many of your threads and advise on this forum and another, and have really enjoyed them.

Thanks!

David

 

I saw someone mentioned port matching both the intake and exhaust, now there are some that feel matching the intake is a waste of time, and I will leave that discussion out of this. But port matching the exhaust is not a good idea unless the manifold open is smaller or protrudes into the head port, it's always been my opinion that having a slight port mismatch on the exhaust with the manifold bieng slightly larger than the head opening is a good thing, and helps flow plus helps prevent reversion so do not hog the head out to match your headers etc.
As Scott pointed out the exhaust on these heads are very restrictive, and even if you only do the exhaust, atleast do that amount. I won't get into the how to on this cause you probably alreeady have a response from about the best around on iron big block ford heads and I can't really add any to what he would tell ya.
On cams stay away from single pattern cams, these are fine if your running a small block chevy which most of them are patterned to work with, but as previously stated aren't good on Fords with restrictive exhaust so find a pattern with atleast 10deg more duration on the exhaust side.