I know a guy who has all the crazy tools and machines that you need to Port/polish, and i could probably get him to do it for me (he does it on motorcycles, so he wasnt sure about doing it for a car). I was wondering if it would be worth it though, and if so, how much would it cost at another shop if he were to decide that he couldnt do it.
Port/Polish
- Thread starter MILNE62
- Start date
Ok well I first of all wouldn't be too keen on going to a bike shop to get car work done. I mean don't get me wrong the guy knows what he is doing for bikes, but their is a reason he has a license for an a small engine mechanic and not a fully certified class a mechanic.
I am not trying to put your friend or contact down here. I am just saying that his specialty is bikes not car engines. that's all I am trying to say.
First off when you say port and polish, which part do you intended on doing? your intake manifold, your throttle body, your intake and/or exhaust ports... there is so much to be done...
It is well worth getting it done, but make sure the person truly knows what he is doing on a car engine before they start. I mean a small shaving of metal if it ever gets into your engine...... well i think you get my idea..
You will see an huge increase, but then again it's getting all of the above ported and polished will need to be complimented with intake, header and exhaust.. then you will get amazing gains and breathability for your engine...
Sorry I don't know the prices as I never got it done... and my friends won't tell me how much it cost them either...
jc
I am not trying to put your friend or contact down here. I am just saying that his specialty is bikes not car engines. that's all I am trying to say.
First off when you say port and polish, which part do you intended on doing? your intake manifold, your throttle body, your intake and/or exhaust ports... there is so much to be done...
It is well worth getting it done, but make sure the person truly knows what he is doing on a car engine before they start. I mean a small shaving of metal if it ever gets into your engine...... well i think you get my idea..
You will see an huge increase, but then again it's getting all of the above ported and polished will need to be complimented with intake, header and exhaust.. then you will get amazing gains and breathability for your engine...
Sorry I don't know the prices as I never got it done... and my friends won't tell me how much it cost them either...
jc
A good port and polish job will go about $1500. That's getting you head done up by someone who knows the flow characteristics of your engine and knows where they need to be improved. I haven't looked at our head yet so I don't know if there is alot of room for improvement or not. What I would expect to be need is a 3 or 5 angle valve job (the valves will seal better), maybe some lighter valves and new springs to aid in high rpm engine speeds, I'd probably just clean up the ports a little and polish them, install a new set of cams, then mill it all down to raise the compression and switch to a single layer head gasket.
This is all pretty much work you want to do if you don't plan on fi, an fi head job pretty much goes to making all the ports as big as possible to get as much fresh air in as possible and getting the exhaust out as fast as possible.
This is all pretty much work you want to do if you don't plan on fi, an fi head job pretty much goes to making all the ports as big as possible to get as much fresh air in as possible and getting the exhaust out as fast as possible.
If your man is experienced in porting performance multi valve bike engines (not H-Ds), and has a good track record, he should be able to do your head too. Id advise against going all out with the porting, because if you hog them out too much the flow velocity will drop off and net gain will be negative through much of the lower rpm band. Id get the head match ported to the intake and chamfered in about 18mm, have the chamber volumes matched, and have the seats cut to 5 angle. The multi angle seats dont really seal any better, but they do allow for a faster less turbulent flow through the valve. If he can flow bench the head and intake together to balance each cylinder before polishing all the better.
If you plan on ever installing a header or turbo, Id also wait on the port job until thats done so the exhaust can be matched up too. No matter what else is done, Ill second the motion that high rate springs and light weight SS valves, retainers and tappets are a necessity. That is first and foremost in supporting higher rpms or more aggressive cams.
Also, be sure you have a comprehensive plan for engine design before hacking on your head. Know what level of performance youre trying to achieve, and what else will be necessary to reach that point. Its always best to have all the other necessary stuff ready before cutting into the head.
If you plan on ever installing a header or turbo, Id also wait on the port job until thats done so the exhaust can be matched up too. No matter what else is done, Ill second the motion that high rate springs and light weight SS valves, retainers and tappets are a necessity. That is first and foremost in supporting higher rpms or more aggressive cams.
Also, be sure you have a comprehensive plan for engine design before hacking on your head. Know what level of performance youre trying to achieve, and what else will be necessary to reach that point. Its always best to have all the other necessary stuff ready before cutting into the head.
MILNE62,
Make Sure you know before hand what your planning to do to your engine. Normally shops have different Port & Polish Jobs for different applications. For Example: A Port & Polish Job for a Normally Aspirated Car will be completely different for a Turbo Setup. So before you go and make changes to your head (which cannot be undone) please plan out your mods.
Make Sure you know before hand what your planning to do to your engine. Normally shops have different Port & Polish Jobs for different applications. For Example: A Port & Polish Job for a Normally Aspirated Car will be completely different for a Turbo Setup. So before you go and make changes to your head (which cannot be undone) please plan out your mods.
a port and polish job won't require higher octane fuel. Changing compression, you can either use a thinner head gasket, mill the head (shave the bottom of the head), use a piston with a higher dome, cc the combustion chamber, or any combination. Changing the compression or advancing the timing it would be advisable to take extra steps to make your engine less likely to experience knock or detonation....one way to do this is to use higher octane fuel.
