guys, just be sure, the gasket its not bigger than the HEAD ports!!!

cause on a lot of cars Ive seen, the gasket is bigger than the ports, so if you port the IM by the gasket, the IM ports will be bigger than the HEAD ports, and that will kill the performance!!!

 

So, I'll pay attention to not grind more than the cylinder head... and let it a little bit rough. Anything else should I know ?

 

I wouldn't port anything unless you are lacking engine efficiency. Meaning not enough air for your demand. If you are mostly stock porting will do little unless you have a turbo then you will notice a much larger gain. If NA leave it alone unless running a large camshaft. Thats just my experience with hundreds of engines.

 

For now, my ''performance '' mods are only Injen cai and Udp. I got an second camshaft with mivec lobes little bit (i can't find the good word, excuse my english) broken. I've called some machine shop to weld it and regrind it... but some say they can't weld it... so I'll see. I was trying to find another way to get a little bit a performance without spending hundread and hundread of money... So this is why porting was an ideas...

 

How about this. Don't port is but instead have then polish out all the casting ruffness inside of the ports. Do a 3 angle valve job including smoothening the tops of the valves. This will allow lower resistance of atimized fuel and air mixture. Allows higher CFM along with better performance without a chance of over porting. Just think about it.

 

Nice

 

Thanks ssp. So I'll let down the p&p intake project. What about the camshaft ? Do you think it can be WELD and regrind ? Changing the stock Catalytic Converter for an hi-flow cat will help my breathing, is it an good mod ?

 

Maybe. I couldn't answer that unless it was right in front of me. You might be better off getting a new one. It just good insurance incase theirs welds don't hold up. Plus when you weld it now your weak link is next to the weld but there is a 50/50 chance it can hold or not. Its all up to you and your budget. Your cam can be reground, I am not really a big fan of it because sometimes the cam grinder can mess it up meaning uneven grinding or high lobes all different lifts. Just find a good reputable cam guy and you should be fine. A high flow cat is good if you have to do smog. If not then get rid of it. Even high flow cats are alittle restrictive. Just my 2 cents.

 

you just told him not to bother with a P&P though, now a HF cat is restrictive on a basic modded NA motor, ralliart or not? come on man...

thrice, american custom cam is reputable, and very reasonably priced for a regrind. do a little more research for yourself, and don't take everything you read from any particular source as gods word by any means.

[QUOTE=above signature to prove a point]fastest NA Ralliart (Under Construction) Testing.... Mods: RRM Header back exhaust, RRM stage 2 cam, RRM UDP, RRM Cylinder Head, RRM Intake manifold, RRM Alum. Flywheel, RRM stage 1 clutch, RRM LSD, RRM CAI, Hyper Voltage system, RRM piggy,[-/QUOTE]

 

it looks like either you or us is getting confused between what you are asking about porting, so I will elaborate a little on what has been discussed.

intake manifold: should be extrude honed or port matched to the intake side of the head, no bigger. you will have some gains doing this, especially if EH is done, but don't expect a miracle since the design is good. you don't want it polished, as Joe pointed out, merely smooth so as not to cause any restriction. he and I will differ in opinion a little, I believe, in that I feel your turbulence is best suited to stay in the head itself. the injector site is just before the transition, and turbulence created before this point will only hamper the airflow since the fuel has not entered the system yet.

cylinder head: intake side can be gasket matched, but anything further should be done by an experienced shop. this is where you should keep the surface less than optimal, but should still stay away from any kind of quick transition. you want the surfaces and transitions as smooth as possible while keeping the actual metal itself rough, kind of like your dashboard if you get the idea. doing a valve job requires special skills and tools, so take it somewhere if you want it done right. same thing with putting it back together, if you don't know (in other words, you don't KNOW) take it somewhere.

for the exhaust side, polished as bright as you can get it, and as long as you don't go bigger than your exhaust manifold there is tons of room to enlarge that side of the head. remember that if you create a huge hole but it runs into a flat surface before it goes to the next component you just created a problem.

for the camshaft, so far we have been able to prove beyond a doubt that you can modify a stock camshaft. obviously this has to be done by a pro, and so should the installation if you aren't comfortable with a pretty big job. the mivec lobes have been modified, if you do the lower end you're on your own the cam specs given to me by ACC are on here somewhere, or I'd post them here. all you have to do is tell them the engine, they know what they are doing.

the head is easier than the cam, in some regards. both require tons of patience and at the very least a spare pair of hands and the tech manual. someone with lots of under hood experience would be best, but a dumbass can hold things or fetch stuff while you are indisposed.

keep reading before you jump into a decision

 

Sorry Dan, sometimes it's hard for me to get understood by others in english, I just do the best I can. So I'll try to clarify the things...

First, the camshaft, I know the stock camshaft can be regrind, I've read a lot about it...The way i'm not sure is about the welds. I've take pic of the cam... As you can see, the mivec lobe is damaged on the top. The rollers of the lifter got stick and it had ''grind'' the top of the lobe.



I'm expecting to get it welds and regrind to get an little more aggressive profile. I know an professionnal place that can do it with no problem for the regrind...but I just would like to get opinion about the welds, good or not. Knowing that I don't have a piggyback to ''tune'' my mods, I know that my gains will be less but should I feel a gain even ?


Now for the port and polish things, I won't touch to the head. The things I want to do, is only take the mesurement of the head intake hole, compare it to the gasket, and check to port my intake manifold a little bit the get the near or same as the gasket... not much. As I read in this thread, i don't have to polish it too much... just little bit the let it rough (like 200 papersand).

For the exhaust side, I have the stock manifold. From what I read, I just have to polish it a lot in the four hole. Like the intake manifold, i do the job the more deeper I can with the tools in each hole of the manifold.

Again, I know the gain will be less without the piggy, but with the p&p and the cam, should I expect noticiable gain or it's a lost of time ?

 

you will have a gain, just not the biggest gain possible.

people weld cams all the time (professionals anyway) and have no issues. it's a matter of the people who do the work. there are videos and articles online, it's not a traditional welding process by any means.

 

Thanks Dan for your advice. I'll probably make a thread when the project will start. My uncle own an performance shop for quads and he uses to port and polish really offen. I'll do the job with him and we'll test it all on the ''flowbench'' he said.

Thread ,pictures and results to come...

 

sounds like you have the perfect resource to help you out already, why are you on here asking us? you don't trust your uncle?

 

Those are the magic words...

GL with the project.