Aluminum shavings from a set of Bulldog heads I ported. Swept up off the floor. Looks like some new kind of dope. Yes, alumadope. LOL.
The bulldog heads are pretty raw out the box. Removed a lot meat from around the valve guides & pockets. Also some rough castings around the valve seats in the chambers. The short turn radius in the exhaust ports needed some work. Intake side not as much. Oil return holes someone already had enlarged them. On one head the middle lower exhaust bolt hole was into the water jacket a little, easy fix. I will have them flowed & check the chamber cc size.
I agree! For example I never check my Bearing clearance's when I build a motor until I make a pass I see my crankshaft in my rear view mirror.
Here's is a flow sheet from one of my sets of Bulldogs for your info. 2006. The intake needed little work but the exhaust was worked extensively with different valves also being tried. This was on a conservative flow bench also.
Whenever I have flow tested folks heads that have been home ported without the aid of a flow flow bench or without the home porter using templates to guide them , 95 % of the time the heads only have picked up some very high lift intake or exh flow, the rest of the lift points flowed less. The other 5 % got lucky with there rework. I am guessing your in the former, not the latter!
Sounds like something you would do. I have a master head porter that has showed me the tricks of the trade.
I don't know him, But I'm just having fun with him. I am going to have them flowed & check the chamber cc size. I will post the results when I get them.
I'm from the home port camp as well,...I don't dispute the advantage of flow resting b4,...after don't se the point myself,..at that point its gonna be what it's gonna be,..unless you're willing to epoxy and weld,...texting during??,..yea like that's feasible for most guys,...and if they were to build a bench guts would just say well your bench isn't accurate. So Instead looking at them and being afraid to touch them,...we actually get after it and use what info is commonly available to make changes without changing the cross section too much,..throat percentage and common sense,....I've never "hurt" a pair of heads,...the cars always ran better than they would with stock heads. And had the pleasure of knowing I done it,..pretty sure know one was born a master head porter or had a bench to start out
I apologize, I don’t mean to sound snarky, just curious to hear what people think there heads need rework wise just by viewing them bare and without taking or posting up any size measurements, no less flow measurements. If you know what sizes ports need to be in relation to there valve sizes used, then why not help folks out and post such up , not just a bag of Aluminum chips? once again not to be snarky but I have seen piles of grinding chips on folks basement floors and them being proud of it, but when asked if they where sure all of that needed to come out in the places they ground on there reply is always the same, there not sure is what they honestly say. One thing you learn very fast with a flow bench and once you have tested enough different kind of heads on them is this, what your eye precives as being streamlined for better high lift flow after a rework is all too many times not what’s needed, especially when talking about the turns that get the air mass into and out of the valve bowl around the valve. once the air passing thru a given port starts to get up to the volume where it can no longer take the easy path in and out ( as in line of site) but is forced to follow the shape and contour of the port, things change in a hurry! Note that Intake port wise it’s possible to rework the port some as to not gain or loose air flow, just make it larger and this will allow the peak Hp of the motor to not nose over as fast. This then makes for the potential for the car to perform better if the needed added rpm can be had. All the above ties in to port air speed. To get back to my third paragraph, here’s a funny personal story. my second set of iron heads I ever ground on seriously I spent a lot of careful time doing so and with out the aid of a flow bench yet. I had read ton’s of porting articles, looked at other heads in a local race machine shop and asked a lot of questions. I also found out what heads like I was using on average flowed stock and ported. My heads intake ports as it turned out in stock form flowed some 205 cfm@28”. With all the careful time I had put into reworking my heads I was sure I had attained 260 cfm since very knowledgeable porters where getting over 280 cfm. Now in my life we move on to 6 years down the road and I now have had my own Superflow bench for two years. I yank those heads I ported years before of the motor and slap them on my flow bench only to find them flowing a mire 20 cfm over stock! And as if that was not depressing enough, that added 20 cfm came in way up at .700” lift which was .150” higher then the cam lift I was running in that motor, all of the other flow numbers at valve lifts below .550” where no more then some 5 cfm over the stock numbers. While being depressed I was glad I did not harm the heads in anyway that I would have to figure a way to add material back in. Once again, sorry for being snarky and I hope that the rework time you have put into your Bulldog heads provides you more performance gain then you where hoping to achieve.
Other things that make up the porting is not getting turbulence in the ports. This can be more harmful than good. Tom T.
Stevem. Don't take it to heart, it does not afend or have to be soft like cotton to me. It's cool. Everyone has their own philosophy on things. I like criticism & giving it right back. The bag of leftover aluminum shavings was a gagg for fun. You're always welcome to give advice to me, no worries.
There are many different types of turbulence and some types are helpful to power production and some are said to be bad. The problem I have with the ones that are said to be bad when having the issue show up on a flow bench is that the test cylinder used on a flow bench is always open, where as in a runnng engine it is not, in fact the piston spends very little time at BDC, and some turbulence issues take time to form/ wind up if you will, time that becomes less and less as the motor gains rpm. The other thing to note is the 95% of the time air flow thru a port is always turbulent, it can not really be laminar. Over the weekend I will try and do a video to post up of the normal turbulence taking place in a Intake port runner and once out of the valve and heading on down the Bore. I will do this video at 3 or 4 different lift point to show how things change with added air mass and velocity.
