engine rebuild, Help!?

[lost888key]

This is first DSM, and turbo car. It is a '91 Talon TSI AWD (God I want to drive this car I could just scream, and do regularly), and have lots of questions.

1. I have never seen a block with egged cylinders, taper yes, egg no. It specs at the bottom, It specs at the top (no ridge either), but it's about .030 over in the middle on all cylinders, Is this a turbo thing? Like I said 1st turbo car, or has this engine been rebuilt by a gorrilila with a drill and a hone?

2. At some point a piece of trash was sucked through one of the main bearings. It has a circular scar around the journal that is within wear tolerances. Normally I would have it turned down, but the DSM manual says not to because It has a special coating. Is this Nitriding of some sort? If so, I can have turned down and re-nitrided, or am I better off getting a different crank?

3. On the connecting rods. Are these coated as well? The reason I ask is because I had considered having them shot peened while they being drilled and shaved for 2g Pistons.

I will have many, many,more questions later, but this will get me to the machine shop.

And before you flame me for not enough info.,
I'm going .040 over on the block,
2g pistons on 1g rods
mild port & polish on head W/three angle valve job & back cut on the valve
big 16g turbo
FMIC (when I find one I like)
equalength exhaust manifold
??? injectors 550 - 720's
upgrade the Auto transaxle (I will be asking transdude many questions)
I'm shooting for between 350-400 hp with bolt on upgradability to no more than 600 with none, 0, zilch knock, else from what I've read this powder keg would explode.

answer the questions, please!!! and any comments, suggestions to help acheive my goals are greatly appreciated

thanks in advance,
Chuck McCloskey

BTW: moderators, If my spelling/grammer sucks, I'm sorry!! I was happy to get past eng comp 1 in college with a C after the third try

 

[candela]

1) no its not normal... however (as I am sure you know) the area of teh cylinder that the piston travels is most effected. Measuring the lower part is quite different.

2) You shoudl probably consider a new crank (used but in good shape) since they can be found somewhat easily and are cheap. IMO better safe and do it right while tis apart.

3) no and shot peening isn't a bad idea at all.

Sounds like you have a good plan. However I would consider either a small 16g (for price) or an EVO 16g as opposed to the Big (660cc injectors) Good luck,

 

[lost888key]

Originally posted by candela
1) no its not normal... however (as I am sure you know) the area of teh cylinder that the piston travels is most effected. Measuring the lower part is quite different.

2) You shoudl probably consider a new crank (used but in good shape) since they can be found somewhat easily and are cheap. IMO better safe and do it right while tis apart.

3) no and shot peening isn't a bad idea at all.

Sounds like you have a good plan. However I would consider either a small 16g (for price) or an EVO 16g as opposed to the Big (660cc injectors) Good luck,

Thanks for the info.

About the crank, new is out of the question like $800 from mitsu. Checked into reman, they don't recoat and called me a liar! Can I source this out of a junkyard, and get one in good shape(i.e. strait, round journals, without scoring)? Not realy sure of of where else to look, ideas?

The turbo is the same price either big or small at darkside racing, and if my math is right, I should start building boost about a thousand rpm sooner and stay above the magic 60% eff. till about 7500 rpm. Does this sound right? I haven't seen a compressor map for an EVO 16g. Do you know where I can get one?

 

[Mike1992]

check out slowboyracing.com cheapest evo3 16g and i think they have the flow maps

 

[candela]

What turbo's are you comparing?
Ever consider a larger turbo?

 

[lost888key]

Originally posted by candela
What turbo's are you comparing?
Ever consider a larger turbo?

Sorry about the long respond time, busy, busy,busy. I was comparing a small 16G and large 16G. I was looking seriously at these because of, price, bolt in, early boost, (not sure though if this is where boost begins to build, where full boost is realised) about 2100 RPM for a big 16G and about 3100 RPM for a small 16G. I still can't find a map for the EVO 16G.

This week I'm cleaning up my head, getting rid of flashing (found bits of flashing stuck in my oil screen, knocked more off when I was pulling my head, assume this is where the groves in my crank came from), port, and polishing. Any advice on porting around the bowl area? looking to improve flow without sacrificing low end. This will primarly be a daily driver, with some scca solo2 use (possibly a camaro or mustang owner with hurt feelings along the way ). Any of the 16G's should give me plenty of for these purposes, so I don't really need a larger turbo

 

[Groomz]

The 4G64 crank is a direct drop in to the 4G63 motor. You will need stroker pistons ( stock rods work fine ). This will net you 2.3-liter displacement. Slowboy sells the cranks for 350$ with bearings, which is the cheapest I've seen new.

 

[lost888key]

Wouldn't you know it, I ask a question after searching for days, then find my answer searching for somthing else. (bowl porting)

On the EVO 16g, does that correspond to a TD06-16G?

Thanks for the stroker idea, but I'm going to go back with a 4g63 crank.

 

[Suparata]

Originally posted by Groomz
The 4G64 crank is a direct drop in to the 4G63 motor. You will need stroker pistons ( stock rods work fine ). This will net you 2.3-liter displacement. Slowboy sells the cranks for 350$ with bearings, which is the cheapest I've seen new.

That crank is remanufactured/ground. A new one is a little more than $350.
Mitch