Polish and port, take 2

[SilverXJ]

I used duct tape to protect the gasket surface on the head.

[SilverXJ]

I CC'd the head tonight. I started with the chamber that I hadn't touched yet that is #1

1: 57.2
2: 58.4
3: 58.6
4: 58.2
5: 58.0
6: 58.4

Should I do anything to bring them all alike, or is the variance not enough to worry about?

Also, I have been thinking about my manifold gasket. I used the one that Doug Thorley sent me. When I port matched the intakes I didn't need to remove that much material. Now I am debating getting another gasket and port match to that if it is larger. Would that give me any gains or not?

[SilverXJ]

I forgot to add a bit of humor..

After reinstalling all the springs I got #1 cylinder ready to cc. Put the plexi with vaseline on the head and started adding water... it started pouring out the chamber.. i them remembered that I need to install the spark plugs.

[Flash]

I CC'd the head tonight. I started with the chamber that I hadn't touched yet that is #1

1: 57.2
2: 58.4
3: 58.6
4: 58.2
5: 58.0
6: 58.4

Should I do anything to bring them all alike, or is the variance not enough to worry about?

NO they will be just fine!
Also, I have been thinking about my manifold gasket. I used the one that Doug Thorley sent me. When I port matched the intakes I didn't need to remove that much material. Now I am debating getting another gasket and port match to that if it is larger. Would that give me any gains or not?

If the gasket that your going to us is larger, It wouldn't hurnt to put a slight bevel to match the gasket, But DON'T try and enlarge the port to match it.


Flash

[kryptoniteXJ]

Hi All,
I just jointed this GREAT Site. I am in the process of building a mild stroker for my '91 Xj 2Dr. 4x4.
At the moment the block is at the machine shop getting prepped. I just got the head back from westside performance (the shop doing the work) I'm going to start pocket porting it soon. The shop said it was a strait not warped head, with no cracks. Its a 7120 casting.
Any tips for my porting??? I don't wanna get crazy with the porting. Can I use my dremel or should I get an air set up??

[4point6]

I didn't have access to an air set up, so to port mine, I got a cheapie electric grinder (about $25 I think), and a variable speed regulator (used for routers - about $20) from Harbor Freight. Electric regulator to keep rpms lower than the non-adjustable 25,000 rpms from on the cheapie grinder. Then I used the porting kit from Standard Abrasives. Seemed to work ok. I have heard of people using a dremel, but I think you might need more power.

[SilverXJ]

I would definetly go air if you have a large enough compressor. A dremel 1) doesn't have enough torque, and 2) the bits are expensive and you will need a lot of the dremel sized bits. Standard Abrasive's website has a good read as does a sit that someone posted earlier. If its not there search for "DIY cylinder porting". Those are good place to get the general idea and such.

[John]

Porting with a dremel can be done but it really is a waste of time and money. The reference to standard abrasive's web site is good advice, another good site to browse is this one, http://www.ruffstuff.com/
John

[SilverXJ]

I dropped the head off at the machine shop. Asked for it to be checked over and a 3 angle valve job with the valves back cut at 32*. They were impressed with the work I had done.

I just remembered something. I have two sets of valve stem seals. One is brown/black and the others are all blue. Which are the better ones?

[gradon]

The red/brown ones are for the exhaust valves and the black ones are for the intake valves(I'm glad I noticed and then read the instructions on the Mopar ones I got). I don't know about blue ones.

[SilverXJ]

I know that eh brown and black ones are for exhaust and intake (one bag is labeled), but the blue ones are for both sides. I'm trying to figure out if they are a different material or what.

[gradon]

I know there are viton seals, which are better(I was reading the mopar engines book), but I don't know what color they are.

[SilverXJ]

Yeah, thats is what I am thinking the blue ones are... but I have use Viton o-rings on a jag and they were grey.

the seals look like this, which was taken from an ebay auction that says they are viton.


However there are vitons that are also grey.

However this leads to another question. Why does one set have seals for intake and exhaust and one set is all the same?

[Flash]

I have know idea on any of them,......but the stiffer spring ones would be for the intake.

the intake valve will have vacuum in the port at idle.....just like the intake manifold will.

intake valve stem need a stronger seal then the exh valve stem.
Just a little logic that may help.

Flash

[SilverXJ]

Two last images for you: