Questions about rebuilding bottom end

[kt239]

I have came to the conclusion that the sound I am hearing from my motor is either a rod bearing or a main bearing so I am going to be pulling the motor and rebuilding it. I do have a few questions that I hope I can get some insight on before I go and order parts from those with more experience then myself.

1. Is anybody running Manley internals or know if they are good to build with?

2. I am shooting in the ballpark of 350-400hp so am I safe with buying kit consisting of a crank, rods, pistons and bearings based strictly off their line of products?

3. I plan on going with 86mm pistons so I can bore the sleeves out for a nice smooth finish but shout I got with the 8.5:1 or the 9.0:1 pistons and why?

4. There is also an option for 150mm rods or 156mm rods so I was wondering what would be the better choice there?

The vehicle is a 95 Talon and here is a link to the site I was looking at. Thanks for any input.

 

[tsi6bolt]

8:5:1 is for a smaller turbo set up and 9:0:1 is for high rev to spool a bigger turbo so iv been told

 

[Below Ambient]

Thats way to much overkill for your horsepower objective, a stock bottom end will handle 500-600 with good tuning...

What are these sleeves you speak of?

 

[lauj2gdsm]

Thats way to much overkill for your horsepower objective, a stock bottom end will handle 500-600 with good tuning...

What are these sleeves you speak of?

Its a honda thing.

 

[scott90gsx420]

Man you will be fine with a basic rebuild going with forged internals is only worth it if your planning on making 400hp and up as the stock stuff won't hold anything above that for a long period of time.. If you are not going to be getting above that then just rebuild the motor and keep the stock internals.. Also what kind of sound is it??

 

[JusMX141]

8:5:1 is for a smaller turbo set up and 9:0:1 is for high rev to spool a bigger turbo so iv been told

Not exactly.

Lower compression = less power extracted from combustion. This means less heat, so the engine is less prone to detonation.

Higher compression = more power extracted from combustion. This means more heat, so the engine is more prone to detonation.


You can use 11.5:1 pistons on a T25 if you wanted to deal with the amount of knock caused from heat generated by both the turbo and the high compression ratio.

 

[TSi Kid]

If you're only looking for 400whp then go with a stock rebuild.

 

[kt239]

@ tsi6bolt
Thanks for the input

@ below ambient
I understand it may be a little overkill but I would like room for expansion in the near future. Current funds permit me to build the motor up to be durable for what I may or may not want to throw at it. And may I ask what the reference of the sleeves is? I plan on boring them out a little bit to have a smooth surface for the new pistons hence getting the 86mm instead of standard 85mm.

@ lauj2gdsm
Honda thing?

@ scott90gsx420
The sound is a loud knocking around 2k rpm and is also noticeable below but obvious around there. There is also a tick coming from the litters which I understand is a normal sound so I want to fix the big problem here being the what seems to be bearing issue. And while in the process I would like to upgrade instead of reuse the old parts since it will be out.

@ jusmx141
Thanks for the information

@ Tsi kid
While the motor is out I just want to replace the internals and would like a strong bottom end for whatever I may do in the future.

 

[Brian O Conner]

If I were you I would go to CI Motorsports and look at there rebuilding inventory. On top of that get some JE forged pistons.

 

[DSMTyson]

Ross pistons and eagle rods with a balanced stock crank, ARP everything, MLS head gasket, and new bearings would be perfectly reliable at 400whp and you would have much more room to grow.

 

[kt239]

I will check them out.. I guess that raises the question of if Manley is a good company as far as durability and reliability? Or are there some components they are good for and others they are not? Cause I was thinking it's easy to just get it all in one package but if that's not a good idea please let me know.

 

[Palmetto_TSi]

Compression in the cylinder adds heat. It is a side effect we wish we could eliminate, but we are stuck with that fact. The higher the compression, the higher the air/Fuel charge gets PRIOR to ignition. Add to that the fact that the incoming air/fuel charge is already heated due to underhood temps, as well as the compression of the air caused by the turbo, and you could easily find yourself in the detonation zone (ping). While ping is hell on all engines, it is nearly fatal to turbo engines. The reason forced induction engines run smaller compression ratios is the fact that most street fuels do not have a high enough Octane rating to prevent this detonation inside the cylinder or a high compression, high boost engine.

Octane is a measure of the fuels ability to resist this detonation, by controlling the speed at which the fuel burns. Octane in and of itself does not add power, it just frees up the available power in the engine by keeping knock and ping to a minimum, thus keeping the knock sensor happy, preventing the ECU from retarding the timing. Timing retard causes a loss of power. So, low octane can cause a loss of available power due to this retard in the ignition timing that is required to keep from blowing the head gasket and internals.

Now, the really great thing about compression is that it creates torque, as well as this undesired heat. The higher the compression number the higher your OFF BOOST torque will be. Off boost torque is something a stock stroke street driven DSM truly could use more of. The easiest way to build this off boost torque without worrying about detonation, is the use of a stroker crank. The extra stroke length give the engine a greater mechanical advantage because the crank shaft (basically a set of levers rotating around a pivot) are longer, thus making it easier to move the same load with the same compression.

Guess what though? With every good in an engine, there is a bad, as we have shown already. The down side to this longer stroke is that the engine mechanically can not handle high rev limits. Moving all this mass, all this distance, then stopping, turning around and doing it again is very difficult. One of the ways to make this easier on the engine is to use light weight components. Forged pistons, aluminum rods, etc... There is actually a formula for predicting this behavior, but for a low to mid HP engine, it is not needed. I'm sure you can google it, or you can read this book... it has a lot of good formulas that will take a lot of the trial and error out of building an engine.

http://www.dsmtuners.com/forums/new...=sr_1_1?ie=UTF8&s=books&qid=1230914291&sr=1-1

 

[brass420]

Another great option in my opinion would be a rebuild using mostly oem mistubishi parts like maybe some modified 1g rods with some 2g, evo8, or evo9 pistons.

Most machine shops that know 4g63's could set you up with something like that or you can check out dsm graveyard.

This will be cheaper than aftermarket stuff and easily be reliable to the 500whp range. (supporting mods and good tune obvioulsy)

Oh, and to keep things simple and cheap(er) stay with the 150mm rods if you do plan on going aftermarket. Otherwise you have to get into different strokes and cranks and it doesn't sound like you need/want all that.

And don't forget about the arp main studs and acl/clevite bearings. Well worth the extra few bucks if you're already tearing the block apart.

Also, try to find a machine shop that uses a torque plate and has experience with the 4g63.

 

[kt239]

@ palmetto tsi
That is a good wealth of information and I would like to know if I was to get a stroker crank and get the 8.5:1 pistons would that be alright to work with? I see an option for a 2.4 stroker kit and id still get the 86mm pistons. Would like a little extra torque but not at the sacrifice of the reliability of the motor. And it still has forged rods, pistons and crank so there shouldn't be much added weight so the high revs shouldn't be an issue in theory right?

@ brass420
Im still debating options in my head as to what I want to do but it seems like the 150mm rods will be the way I go because with the 2.4 stroker kit that is what is included. I would like to get the most bang for my buck and the 2.4 kit is about the same price as the standard 2.0 kit so I figure I will go with that unless its a bad idea for any reason.

 

[crusada]

Well with the 2.4 plan on a new drive train/ trans as well just to warn you

 

[Below Ambient]

@ tsi6bolt
Thanks for the input

@ below ambient
I understand it may be a little overkill but I would like room for expansion in the near future. Current funds permit me to build the motor up to be durable for what I may or may not want to throw at it. And may I ask what the reference of the sleeves is? I plan on boring them out a little bit to have a smooth surface for the new pistons hence getting the 86mm instead of standard 85mm.

Well I can say that I have seen a reliable 750 HP from an Eagle/Scat rod combo (my friends car), but hes a machinist... Instead of buying a reciprocating assembly, I would consider finding yourself a machinist who is familiar with these engines, buy the parts and have the shop you choose blueprint and balance the assembly...

If I were in your shoes I would just grab some rods and pistons, leave the crank alone (polished and blueprint at the very least)... that should be good for 600+ HP so long as its tuned and blueprinted properly... concentrate your funding on the fuel system, maintenance, and maybe grabbing what turbo you want to run...

I have observed too many experiences where people just buy parts and put them together, then they blame whatever place they bought them from for the eventual failure...

 

[Palmetto_TSi]

with any stroker, you can run the lower compression. Because you make up for the loss of power due to the burn of the more potent charge with mechanical advantage of the longer stroke. You will also enjoy the faster spool times you get from a larger displacement engine. By making a bigger engine, you force more exhaust through the hot side of the turbo. Thus, spooling the turbo that much quicker. The combination of the mechanical advantage from the longer stroke, and the faster spool times, makes this combination an excellent street option. However, as stated above, make sure you upgrade the drivetrain if you plan on using all this torque very often.

 

[Palmetto_TSi]

Well I can say that I have seen a reliable 750 HP from an Eagle/Scat rod combo (my friends car), but hes a machinist... Instead of buying a reciprocating assembly, I would consider finding yourself a machinist who is familiar with these engines, buy the parts and have the shop you choose blueprint and balance the assembly...

If I were in your shoes I would just grab some rods and pistons, leave the crank alone (polished and blueprint at the very least)... that should be good for 600+ HP so long as its tuned and blueprinted properly... concentrate your funding on the fuel system, maintenance, and maybe grabbing what turbo you want to run...

I have observed too many experiences where people just buy parts and put them together, then they blame whatever place they bought them from for the eventual failure...

Plus 1 on all these points

 

[kt239]

So if I am to get the stroker kit I should defiantly take it easy on the throttle until the drivetrain is upgraded then? Seems more involved then I want but at the same time the extra displacement almost seems worth it. But the one fatal downfall of this car, in my opinion at least, is that it is a automatic. The transmission seems to be pretty solid but it does have 98k on it so I dont know how much abuse it will take not to mention the axles and driveshaft.

 

[TSi Kid]

Run e85 to eliminate you detonating and you'll be set

 

[Below Ambient]

So if I am to get the stroker kit I should defiantly take it easy on the throttle until the drivetrain is upgraded then? Seems more involved then I want but at the same time the extra displacement almost seems worth it. But the one fatal downfall of this car, in my opinion at least, is that it is a automatic. The transmission seems to be pretty solid but it does have 98k on it so I dont know how much abuse it will take not to mention the axles and driveshaft.

It'll take a ton of abuse, so long as its in good working order... Sounds to me like you need to do some maintenance to get you familiar with the car before you start building, you would be surprised how much abuse these cars will take...

 

[Palmetto_TSi]

All that needs to be done if/when you build a stroker, is not let the rev limiter be adjusted to more than about 7400, unless you really spend a lot of time, money getting the assembly balanced. Then your piston feet per second is still going to be kinda high.

Really, I recommend reading any and all books related to engine building, and this specific engine. Take as much as you can from each book. Learn as much as you possibly can before building your engine. You can throw a lot of money into a performance minded engine, and if it's not done properly, or not properly cared for afterward, I promise you will be losing most, if not all that money through blown engines, turbos, heads, driveline parts, etc... Take your time, do it right and you should be fine. If you don't trust your building/tuning skills, get a prebuilt engine, from one of our many reputable sponsors and take the car to a professional tuner to have it dialed in.

 

[kt239]

Thanks for all the great information to everyone who has chimed in on this topic. I just placed an order for a book I been seeing pop up in a few different threads on here (How to Build Max-Performance Mitsubishi 4G63t Engines) so after I receive this book and weigh out all options I will dive into buying parts and getting this build going. I almost have the motor out, its hard to get things done over here with the busyness of life but im making my progress a few hours a day everyday. I capped my build between 3k - 4k so hopefully I can get a good bit of power out of this car.

 

[Xeiros]

Thats a very informative book, as if it's the one I've got, it was co-developed by one of the Road Race Engineering guys, who are gods among men. Read it well, there's a lot of good info in it, and they make a list.

On your list, list all the things you want from it, and all the things you'd like from it, and then all the things you need from it. From those lists, you can come together with a pretty decent idea of what you're gonna have to build. Not everything can be a Magnus built monster with no money spared, and you don't want to do a stock rebuild on everything either. Pick your parts well, and ask questions if you're not sure.

 

[Helifax]

manley rods are really nice and well priced. for 400hp levels i'd get their standard rods, no need for turbo tuff ones unless you plan on making 700+hp