Basic Rebuild

[GalantGreg]

Well, I'm pulling the motor out of my 98 Talon in preperation to go to the Machine shop. I'm going to do a basic rebuild on this motor. I'm not planning on going over the top. Been there done that. All of the usual thing will be don to the motor, hot tanked, honed, yada, yada, yada. I came across some .40 over pistons. Just by adding these, how much more compression will I be adding? How will this work in conjuction with the hairdryer T25?

 

[dsm-onster]

Based on an 86mm bore (.04" over), 8.5CR to 8.52CR . . . Not very much. Total displacement goes up about 2%.

 

[Rob10_99]

I wouldn't have them bore your stock bore block out to 40 off the bat. Save it for the next rebuild.
Unless you can get them cheap and their forged....
It's not a 7 liter engine getting punched out 80 over, your not gonna see a displacement increase =)

 

[GalantGreg]

That's good to know. I am going to break the motor down tonight to get a better look at the spun rod. Perhaps I'll just hone the block and get new rings.

 

[burkgonzo]

I would hone if I could get away with just that. I wanted to that with my build by my engine builder found a small score in the wall

 

[toofast82]

If they need to bore it, I would recommend going .020" over if possible. There really isn't much to gain power wise by boring because our engines are so small. It's more useful to correct cylinder imperfections, and going smaller may allow you to go .040"+ later on if needed

 

[GalantGreg]

Picked up my motor today. It was in bad shape. The pistons were toast. I put in a new set of Toplines. The spun rod was built up and the crank was polished and balanced.

 

[toofast82]

Looks good! I see the cylinder head in the pickup bed too.
What did you end up having the cylinder bored to?

 

[GalantGreg]

Nothing drastic. Just the standard bore.

 

[BogusSVO]

how was the head surfaced?

 

[GalantGreg]

how was the head surfaced?

Heck I don't know. Rest assured, my machine shop is top notch though.

 

[BogusSVO]

well I hope so!!

I just got a head in, that just came from a machine shop, thats supposed to ge top notch on the 4g63 heads, and it was belt sanded.

hope the deck of yours looks like this....

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

 

[TSIfreek]

well I hope so!!

I just got a head in, that just came from a machine shop, thats supposed to ge top notch on the 4g63 heads, and it was belt sanded.

hope the deck of yours looks like this....

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

Yep thats my head.
Post up some pics if you would Dale.
To everyone out there please take the advise of asking what will be use to surface the head.
To my surpise shops still use a large belt sander to clean up the head. Tell the shop what head gasket you will be using for the proper surface finish.
Here is an example of what we are talking about.
YouTube - Resurfacing an Aluminum Cylinder Head

 

[GalantGreg]

well I hope so!!

I just got a head in, that just came from a machine shop, thats supposed to ge top notch on the 4g63 heads, and it was belt sanded.

hope the deck of yours looks like this....

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

I have no worries when it come to the work of this guy. That's why I've been using him for two years now with no problems. This is my 2nd DSM I've done there. I may not know all the proper techniques that machinists use, but I know whatever it is it is top notch.

 

[BogusSVO]

cool!

post a pic of the head surface finish, that way others can learn what to look for!

 

[GalantGreg]

Here are some pics of my head.

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[TSIfreek]

Above thats how my head surface looked when I had it first done. I would not use an MLS gasket on that head it wont seal for you. An MLS gasket surface needs to be done on a machine with a cutter not a belt sander like you have there. BogusSVO has some great pics and a video of what the surface needs to look like.

 

[GalantGreg]

My build is not a high compression hot rod. Like most here. I decided to go back to basics. No high dollar parts. Just a basic dependibale turbo car. My engine machinist is top notch. Been doing this kind of work since before I was born.. Only a few upgrades I will reveal later.

 

[BogusSVO]

if you measer the 4 corners of the head, I doubt you wind the head is square.

I hope you are runing a composite gasket.