Port and polish 4efte cylinder head
- Thread starter frass-ed
- Start date
Sound Per4mance VI
Member +
would this mean a head is port and polished?
Three angle cut to maximize performance
Resurface by diamond cutter for true surface and computer control for taking the least metal cut
Pressure check for unseen internal crack
Precision machine to assemble without human error
Three angle cut to maximize performance
Resurface by diamond cutter for true surface and computer control for taking the least metal cut
Pressure check for unseen internal crack
Precision machine to assemble without human error
350ep70gr
Member +
It is easy to do a basic diy port and polish job to a 4e-fte head. All you need is a dremel with stones, sandpaper, practise, and little step at the time and a lot of time!! I made two heads at the past and seems to work perfect (I had experience with 4 cyl bike heads before)
A simple guide for 4e-fte head is (what I do)
1. Intake ports.
At first you take an intake gasket and with a pencil you paint the inner line on the face of the ports. This is the maximum point that you can put out the metal from the out side of the port. (Match the gasket and the head). Inside the port you smooth everything (usually flash from moulding) till the valve guide. I suggest to not going further than the valve guide if this is your first time. You will also notice that further inside the port has a wall that diverse the port in two ports. The face of wall must be knife edged so use 45 degree when porting from both directions. After you smooth everything with sand paper but not a mirror finish. Mirror finish can be only 1-2 cm (till the injector).Mirror finish after injector is bad for mixing the fuel. You can feel by finger time to time when grinding and you will see where needs grinding. Some cut the little part of the valve guide that inserts the port but I don’t recommend because life time of the valve-seat-guide are decreased. If you plan to go to higher rpm don’t think about at all. Also something very important is valve throat. As you see from the chamber through the valve seat the smallest diameter is the throat and this must be smooth where valve seat meets the head. Be very careful there because no scratch at the seat is allowed. Also this diameter must be 85-90% of the valve diameter but can’t do this by hand. You need a special grinding tool.
2. Exhaust port.
Same as intake. You put the gasket, paint, grinding (match the gasket with the head) (some say that should match the gasket perfect with the head, some other say to leave a small step. I left a small step of 1mm around the gasket.) The divorce wall must be knife edged and the difference here is that the exhaust ports can be mirror finish. (I use water with a water sand paper from step 320-600-800-1000grid.The valve throat must be 85-90% of the valve diameter.
3. Compresion chamber
You smooth everything with sand paper and wd-40 or water or petroleum or grinding oil (additives give a very good mirror finish.)
Very important here is to match the volume of the chamber with each other. I think that 4e-fte head is 10cc(not sure).If you measure lets say all the chamber and the bigger is 10,5cc you must grid the rest 3 of them to 10,5cc or add metal by welding to the bigger to match the smaller. All must be equal.
An other tip is when you go with bigger valves (I have 1mm bigger custom valves) you need to unsround the valve to the chamber wall at least 2mm around. If you go with standard valves don’t bother you don’t need this.
4 Valve job.
3 or 5 angle job helps more than all i write till know. (I suggest 5 angles)Need professional tool to do this job or go to a shop and ask for five angle job. Reseat the new valves (necessary). Check two times that is no leak between valve and seat. (Important).
5. General tips.
Cover all surface that gasket are touching because we don’t want a scratch by accident there.
Do little steps at the time when grinding and try to feel the surface by finger time to time.
USE PROTECTIVE GLASSES (believe me it hurts when a small piece of aluminium go to your eye.)
Don’t hurry.
Resurface the head after all
Use harder valve springs
Intake cam with more duration and lift (or both cams)
New gasket all around
Match intake manifold to the new port. (Intake runners can be mirror finish)
Insulator between intake manifold and head (custom)
And that’s all.
Before start the job try this link. Is very good guide.
http://www.sa-motorsports.com/diyport.aspx
Good luck.
A simple guide for 4e-fte head is (what I do)
1. Intake ports.
At first you take an intake gasket and with a pencil you paint the inner line on the face of the ports. This is the maximum point that you can put out the metal from the out side of the port. (Match the gasket and the head). Inside the port you smooth everything (usually flash from moulding) till the valve guide. I suggest to not going further than the valve guide if this is your first time. You will also notice that further inside the port has a wall that diverse the port in two ports. The face of wall must be knife edged so use 45 degree when porting from both directions. After you smooth everything with sand paper but not a mirror finish. Mirror finish can be only 1-2 cm (till the injector).Mirror finish after injector is bad for mixing the fuel. You can feel by finger time to time when grinding and you will see where needs grinding. Some cut the little part of the valve guide that inserts the port but I don’t recommend because life time of the valve-seat-guide are decreased. If you plan to go to higher rpm don’t think about at all. Also something very important is valve throat. As you see from the chamber through the valve seat the smallest diameter is the throat and this must be smooth where valve seat meets the head. Be very careful there because no scratch at the seat is allowed. Also this diameter must be 85-90% of the valve diameter but can’t do this by hand. You need a special grinding tool.
2. Exhaust port.
Same as intake. You put the gasket, paint, grinding (match the gasket with the head) (some say that should match the gasket perfect with the head, some other say to leave a small step. I left a small step of 1mm around the gasket.) The divorce wall must be knife edged and the difference here is that the exhaust ports can be mirror finish. (I use water with a water sand paper from step 320-600-800-1000grid.The valve throat must be 85-90% of the valve diameter.
3. Compresion chamber
You smooth everything with sand paper and wd-40 or water or petroleum or grinding oil (additives give a very good mirror finish.)
Very important here is to match the volume of the chamber with each other. I think that 4e-fte head is 10cc(not sure).If you measure lets say all the chamber and the bigger is 10,5cc you must grid the rest 3 of them to 10,5cc or add metal by welding to the bigger to match the smaller. All must be equal.
An other tip is when you go with bigger valves (I have 1mm bigger custom valves) you need to unsround the valve to the chamber wall at least 2mm around. If you go with standard valves don’t bother you don’t need this.
4 Valve job.
3 or 5 angle job helps more than all i write till know. (I suggest 5 angles)Need professional tool to do this job or go to a shop and ask for five angle job. Reseat the new valves (necessary). Check two times that is no leak between valve and seat. (Important).
5. General tips.
Cover all surface that gasket are touching because we don’t want a scratch by accident there.
Do little steps at the time when grinding and try to feel the surface by finger time to time.
USE PROTECTIVE GLASSES (believe me it hurts when a small piece of aluminium go to your eye.)
Don’t hurry.
Resurface the head after all
Use harder valve springs
Intake cam with more duration and lift (or both cams)
New gasket all around
Match intake manifold to the new port. (Intake runners can be mirror finish)
Insulator between intake manifold and head (custom)
And that’s all.
Before start the job try this link. Is very good guide.
http://www.sa-motorsports.com/diyport.aspx
Good luck.
Sound Per4mance VI
Member +
thanks, rep added... does the description aI stated above mean the head has been port and polished?
350ep70gr
Member +
Thanks.Nope. Port and polish is my state above. But 3 angle job is a very good start to add in performance. Sourface cut is a typical job that is almost necessary when you take off the head.(Propose of this is to be a straight head and seal better with the hg and avoid hg failures.) Pressure check is a typical job for finding small crack that could give a failure.For this one "Precision machine to assemble without human error" i dont know what you mean. The head assembly is made by hand.
Sound Per4mance VI
Member +
how much does the head weigh?
350ep70gr
Member +
Complete with everything installed i imagine close to 10kg. Not sure btw.