Well I decided to start doin something with all the I have laying around the shop. I just stripped a set of heads and now I am ready for the porting after they come out of my buddy's hot tank. Some of the valve guides need work, probably getting that done after porting and polishing. This is new to me, so I will try and take some pics and see if I can clean up those pesky smog humps;)
I will be using some steel rasps and finishing up the polishing with my foredom.
aluminum or iron heads? be careful if they're aluminum, it's easy to get carried away lol
Just stock iron heads. Yeah, I am familiar with porting aluminum, I ported chainsaws and dirt bikes on the side. This will be the first car head I port. I have an idea what to do, just gotta do it now. Do you know if HSS rasps work well on iron, or do I need carbide rasps?
no clue, i've always used carbide and stones.. and cheap harbor freight bits, too lol
I'm gonna keep an eye on this thread, I want to try porting my E7s before they go on the engine I'm building.
what do you need to know? i can give you a few quick tips.. here are a few to get you started
- using an intake gasket, mark the area the gasket doesn't cover.. then take your bits and open the head up to that diameter.. DON'T just open up the end, this will create a balloon effect which will not help you.. go in as far as you can reach and open it up evenly, to ensure flow consistency.. once you think you're done, check your work by matching the gasket back up to the head.. if all is good and well, continue to the next step
- with the valves removed, round off any shaft edges inside and remove any casting slag (you'll know what i'm talking about as soon as you see it).. something i learned from modello tech (i took a 2 week head-work class) is to take a good deal of material off the casting around the valve guide, like my extra py picture below LOL.. aside from that, just finish the posting you started from the intake side.. try to keep it consistent from intake runner to intake runner.. the better matched they are, the better the outcome of your time spent..
- the exhaust ports, aaah yes.. super sucky job, but knock down the EGR humps.. everyone here will agree, that is practically a must to get some decent power out of E7's.. but first, follow the very first step you did with the intake side.. trace the gasket to get your borderline. from then on, follow the steps listed above and you should be in pretty good shape..
- after that, take a white polishing stone to remove some of the roughness.. then i like to take a piece of 120 sand paper and run it inside the ports to knock it down a bit more.. do NOT go haywire and make the ports smooth like a baby's butt.. leaving a little roughness behind helps with fuel atomization
NOTE: this is NOT going to be a HUGE increase on performance, but it should be noticeable (especially with the exhaust port work).. something else i like to do is take a wire wheel on a grinder and spend a minute or so on the combustion chambers.. it helps remove some of the 'wrinkle casting' that usually gives the carbon deposits something to cling to
so much for 'quick tips' LOL
Awesome, thanks. That's good info, I can't wait for my next day off. I want to really dig deep into this engine, really build it right. Don't want to hijack this thread though. :D
Well, I got started on one exhaust port today, progress is remarkably slow! 50 min and almost got 1 smog hump removed. Am I supposed to fill these holes with JB Weld?? I am also thinking I have the wrong rasps for the job. Seems like they are not even touching the steel a drill bit would be faster.
are you using a drill or dremel?
Air powered die grinder, dremels aren't powerful enough for my liking. I switch over to a CC Specialty Foredom tool for finishing work, like a dremel on steroids. I am sure the burrs I am using are not cut out for the job!
Shadow,
Do you fill in the smog hump holes with anything?
Hopefully a die grinder, or something air powered, lol.
I've done some metal polishing with a dremel, and while that wasn't so bad...I couldn't imagine dying of old age before a drill got done with what he's doing...
it was a question that had to be asked lol i've never messed with E7's.. someone else would have to clue you in on filling the holes in.. i'd imagine you should fill them in, but don't know if JB weld is what people use
I don't think a drill, dremel, or electric die grinder would last for more than 5 minutes with this job. Maybe I will try and weld the smog holes shut! I don't think it would be too risky to try jb weld as this is the exhaust and even it falls out, it's not going through the engine. I have usually always just bolted a set of aluminum heads on and called it good, I can't afford to buy aluminum heads for my fleet of cars and I plan on thinning the herd once some of em get back to running. I have to say just looking down the exhaust port there is a huge difference already and the smog hump still isn't completely gone!
i'd imagine the smog humps are going to be the hardest part lol plasma cutter! LOL i don't think the head would like that very much lmao
From porting my 2.3 head, My advice
WEAR A MASK, iron dust hurts lungs.
Get some good carbide stones, it is unbelievable how fast they go through iron.
Plus pretty much everything Shadow said.
For aluminum I found rubbing a cutting burr in grease kept the aluminum from gunking up in it.
Ok, I got a set of carbide burrs. Got all the smog humps removed from 1 cylinder. Also cleaned up the intake flow around the intake valves. Now for the bad news, I hit the water jacket in one spot, I welded it up, cleaned it up, but I have go over it one more time and then pressure test the head to make sure I didn't kill it. I am also going to be welding up the smog holes. Also I didn't buy the extended shank burs, now I see that I need them! It is too bad I couldn't do what I wanted with the head, but you can only go so far, and then you hit water.
I will also be doing the valve guides and redoing the valve seats.
Ok, so I bring the heads to my buddy (who owns an engine machine shop!!) after he stopped laughing, he picked up the head with the welded water jacket and threw it in the s metal bin without saying a word. I wish I would have grabbed the non ho head first, then I wouldn't feel so bad for wrecking it. Anyways, I think I have a basic understanding of how to port a head. I can do a full port and polish in probably 6 hours. (3 hours per head). Those smog humps take up the majority of the time and my buddy talked my out of welding the smog holes, he says welding cast is not a good idea and that they would come off within the first few heat cycles of warming up and cooling down. I kinda wanted to try it, but I also don't want to wreck a freshly rebuilt motor. I have a thing where I have to try stuff for myself before I learn. I will try and figure out how to get some pics up, my printer died and I don't have a USB cable for my camera.
Ok, according to my buddies flow bench I am still nowhere near gt40 heads, BUT with some more work I could get closer! I did not port the areas that benefit more, I didn't really didn't touch much of the inside radius, my buddy say blending the inside radiuses will help more than I think. So I did a little crash course feeling with my finger what a better head is supposed to feel like. Also he said to do BOTH heads at the SAME time, this will help them be more consistant to each other. I honestly thought that the outside radius would gain more than the inside, but I guess the inside is more important.
PS: When I said I would open up a porting shop beside his engine shop, he laughed and said he would sponsor me just to keep himself entertained. Let me tell you I spent as much time as he spent on my aluminum heads, and I killed 1 head and still didn't achieve my goal of attaining gt40 flow out of E7 heads.
Why not just start with GT40s from the get-go?
Because I didn't want to use a decent set of heads to learn how to port on. GT40 heads are a little more hard to come by here in my area as well! I haven't really enlarged the ports yets, mostly just removed smog humps and cleaned up the flow around the valves. With some longer shanked burs I can clean out the exhaust ports better and also might get a polishing kit. I am sure I can get close to gt40 heads with more work. I have 6 sets of E7 heads, and up here the junkyards charge as much for gt40 heads as you can get bare aluminum heads for.
wow, the junkyards near you are a ripoff.. i only pay $100 a pair, beings it's a u-pull it and it doesn't matter what the heads come off of..
but as for getting them close to P heads, good luck lol.. a little porting on a pair of P heads makes the E7's look like model t heads, in terms of flow