Head work questions.

Rootna318 · Post by **Rootna318** » Mon Nov 12, 2012 10:47 am

Ok, i have an 03 se and i have a spare head with a machine shop at my disposal. UNOH college has some fancy tools so im having the spare port/polished and decked. my question is how far can i go on the deck to boost compression? ill be getting a crane 10 mid range cam to go with it. on another forum i had heard about .050 being done but seems a bit much. So, how much can i take off? and how much can be taken while porting?

Post by **occasional demons** » Wed Nov 14, 2012 11:25 pm

Meh, if you are going to spend $ on a cam, go with something other than the 10. You won't be able to tell it has been changed. Might gain 1.5 hp.

.070" has been removed, but I believe the pistons were also worked for more valve relief.

I would stick with .030" to .040" tops, get an adjustable cam gear, and an '01 R/T, Crane 12 or Comp 400 cam.

With the '02 R/T cam and mild porting on my SE head, it didn't really compare to a mildly ported R/T head with the same cam.

Basically, you are going to need a bit more than one step above stock to make a noticeable difference. With the '02 R/T cam, I really don't have a difference in highway fuel mileage, if that's what you are worried about. I doubt the '01 cam would be much different.

Looking back, I wish I had gone with a 400, but the price on the '02 was too tempting.

In addition, the '03 PCM is going to be a bit tougher to get noticeable gains. The parameters are a bit more strict.

Milling the head will only get you close to the '02 and older compression ratio of 9.8:1 anyways. It will help some, but not an earth shattering amount.

But hey, mill it, port it, and learn something. It's why you are there.

Or just port it, and save up for the turbo option...

r/tguy02 · Post by **r/tguy02** » Thu Nov 15, 2012 8:01 am

yeah .040 is about it, at .050 you are getting into the valve seat.

Rootna318 · Post by **Rootna318** » Thu Nov 15, 2012 12:24 pm

well i know its not big hp or anything like that, but i have decided to go for a 2.0l N/A build, im not expecting high hp or anything but its my daily so. As for the head, i guess the deck will be dropped .040 i could go the extra down to .050 because we have everything to take care of seats and stems but i dont really want to push the limits just yet. i can always have more taken off later. the school will always take a project if someone needs it done.

thanks for the choice on cam, i have seen the 400 on ebay for 200. theres a bunh of them.

Also i forgot to mention, this is a '96 SOHC head, it does have the egr but its being closed, aluminum welding class to make sure its sealed.

One more question, if i went ahead and did all this and sold the head as a bare head with stock cam, rockers, and valves and springs? i know the stok parts dont add much for value. but what would it be worth?

r/tguy02 · Post by **r/tguy02** » Fri Nov 16, 2012 7:21 am

you'd probably get maybe 50$ for a stock rebuilt base sohc head. they're a dime a dozen. if it was say ported and polished you could get more but all stock not really.

NickKo · Post by **NickKo** » Fri Nov 16, 2012 7:54 am

WHATEVER you do, do NOT touch the floor of the port, or 'grind down the humps'.
You have been warned.

- Nick

Rootna318 · Post by **Rootna318** » Sat Nov 17, 2012 6:13 pm

ok, well it will be decked .040 and port and polished. so thats what i will be selling.

What do you mean by the floor and the hump?

not sure if i understand or if i have heard what your saying in just other terms.

Post by **occasional demons** » Sat Nov 17, 2012 11:27 pm

The floor would be the bottom as it sits on the engine. It would be OK to gasket match tho. For gasket matching, you would need a Magnum IM gasket. They are under $10.

But if you do gasket match, be sure it is specified in the FS listing. The buyer's IM would need at least to be matched to that to avoid flow issues.

The plastic IM's would probably be fine, as they are pretty close. But the Magnum IM may have casting tolerances that can be improved on.

The magnum gasket is about as big as you want to go, since the o rings on the plastic IM's may get sucked in if you go too large. You would be limiting your potential buyers by going larger.

The humps are on the exhaust side. They look like they are blocking about 50% of the port from looking in at them. But they are there to help direct the exhaust gasses out of the head.

It is OK to smooth them, and remove casting flash. But you don't want to flatten them. For the overall port size, by removing them, you will create back pressure in the port. The gasses will stall from lack of velocity, and be in the way of the next exhaust pulse.

Welding the EGR port is not really necessary, and might cause issues from the uneven heat on the head. You can easily make a block off plate, or buy one for dirt cheap. The gaskets are cheap too. I made my own from a small scrap of aluminum, and a thin piece of copper for a gasket.

Or you could just use a pipe tap and plug for that matter.

NickKo · Post by **NickKo** » Sun Nov 18, 2012 10:50 am

occasional demons wrote: Welding the EGR port is not really necessary, and might cause issues from the uneven heat on the head. You can easily make a block off plate, or buy one for dirt cheap. The gaskets are cheap too. I made my own from a small scrap of aluminum, and a thin piece of copper for a gasket.

Or you could just use a pipe tap and plug for that matter.

All 2000 ( and probably most, if not all 2001) Neons have a "block off plate" for the EGR port, installed.
The next time you are at a junkyard, take one.

- Nick

Rootna318 · Post by **Rootna318** » Sun Nov 18, 2012 3:58 pm

ok, thanks guys i didnt know about the curve in the exhaust side of the head. ill be port matching it to the magnum intake gasket because thats what will go on with it. and the egr i meant theat a plate would be welded on but seeings how it is aluminum and so close there it will just be getting a block off plate. keep in mind this is a 96 head going on an 03, two ends of the years but match right up other than the egr.

Post by **occasional demons** » Sun Nov 18, 2012 10:16 pm

Well if you did plan to sell it, having the EGR welded shut would have been a bad move. It would eliminate any 1gn owners that need to pass emissions from your customer base.

They use the o2 sensor to tell if the EGR is functioning. So there is no simple way to by pass it.

Rootna318 · Post by **Rootna318** » Tue Nov 20, 2012 3:42 pm

true, good point. guess ill just make the block off plate. just incase i end up selling it.

RSwain · Post by **RSwain** » Tue Mar 12, 2013 12:58 am

I put a 95 head on my 03, I used a 1/2" block plug that I flared slightly by pinching with diagonal cutters. Drove it down into the egr port with a drift. No issues, cost me 50¢.

Rootna318 · Post by **Rootna318** » Mon Apr 08, 2013 5:51 am

Well, I have the plug to seal the egr. The head will be decked .050 down and have a mild p&p then be gasket matched to the ITB intake manifold.