Hello all,

I am currently into my first motor build. I got fed up trying to keep in contact with various vendors and I decided even if it was the same cost, I'd still rather learn to build a motor for myself.

Anyways,

I'm curious as to what clearances everyone is running. I plan on using 20w50 brad Penn in my motor. I'm going to be making some serious power on my engine however I do intend to street it eventually as well.

From what I gathered people are running the following clearances:
MAIN: .002-.003
ROD: .002-.0025
Piston2Wall: .0045-.0050 *Wiseco recommends .0035?*

Let me know your thoughts, I'm not entirely what specs I want to follow. Any help is greatly appreciated. I don't want to build this motor wrong!

-Alex

 

Anyone?

 

Don't want to be "that guy", but if you search you might find what you're looking for.

With that said, given that I have no specifics on your block, internals, turbo, HP and RPM goals... I can't really provide you with a specific number to use.

What I can say, the numbers you provided will work in most cases. Try it out

 

I was in the same situation last year building my 1st engine. I went with .0022-.0025 on the rods & mains and .004 P2W. The pistons are a little loud when cold but I would have went .0045-.005 if I had to do it again. Using BP 20w-50 as well.

 

call MAPerformance. i bet they would tell you what they use on there on there blocks.

 

Shop manual will give you that answer for stock applications but would follow the same for building your block as well.

 

I have searched, which is why I have the numbers I do. I also have a 4g63 Builders manual as well as the factory service manual.

2.0, standard bore, stock uncut crank. I'm running Crower rods and Wiseco e85 pistons.

I will be running 500-800hp. I won't be limited to one turbo but I plan on running the **** out of the motor 9000 rpm+.

Thanks for your input!

I have the factory manual and there is no way I'm following those clearances. Way way way too tight.

 

read this it may be of some help to you

https://www.evolutionm.net/forums/al...o-9-build.html

as DRC said, build it based on your power level and usage.

 

You just described 2 radically different engines, a 500whp motor that needs to rev to 9000 is totally different than one that makes 800+ and needs to rev to 9k. 9k in and of itself presents several different design challenges to clearances.

Not to be a dick but I might come across like that-

http://www.thatvideomagazine.com/new...nny-ten-racing

Watch this and listen to the part about compromises in how the car runs (near the end).

Aaron

 

Sobo: id recommend going to speedtalk forum and reading up there also. good info throughout that forum. i hope you have got really good measuring tools also so you can double check your machine shops work.

 

No offence taken man, I'm here to learn.

I understand there is a broad requirement for this motor. However, I intend on shooting for multiple records for the same engine. IF i need to tear it apart and re-clearance it, that's not an issue for me. The car will be a dedicated track car until later in it's life.

So lets narrow it down. I expect fully to be running around 700 wheel on a MD. Although 9000rpm will not be an everyday occurrence, I would like to be able to spin it that high if the situation or turbo calls for it. I am balancing my entire rotating assembly with the utmost care.

So goals: 700whp, 9000rpm rev limit.

-Alex

 

.002"

I wouldn't run the main's looser than the rods either.

 

At the end of the day.......

That was an awesome rant. I went to grad school with a guy from jersey, and he always said I have that weird California accent.

I just went to SEMA and it was tough to see where anyone makes a good living without selling 32 inch rhinestone wheels.

 

Very good video.. Thanks for posting

The problem is, the 4G63 is wayy too easy to make power with and people see 7-900awhp builds popping up all the time now-a-days.

The truth is, 800awhp is WELL over 200HP per cylinder! If that doesn't sound like a lot to you, apply the 200HP per cylinder to a V8. How reliable and normal does a 1600HP Mustang sound to you? Most turbo 4G63's offered only came with about 200HP in ALL FOUR cylinders, sometimes 5-10 less or more... it was only the factory tuned out 4G63 built for the Evolutions that made more than 50HP per cylinder and even then they rarely exceeded a 75HP/cylinder figure.

Place the above in perspective when deciding on gaps and clearances while building your ~800HP engine. You're looking to make 3-4 times the factory amount of horsepower, essentially a HIGHLY strung out race engine that you'd also like to be reliable on the street. Now take a look at clearances needed for factory engines and decide on your own fine balance of too much or not enough.

In all actuality, the 4G63 is such an amazing motor that you have a decent margin of error. You could go too big and essentially have zero issues if you keep your oil pressure in check with the correct weight oil. Only downside would be increased wear on cold starts... Now too tight is never a good thing and too tight does exist when using factory clearances on a motor producing 4 times the factory power.

Hope this helps!

 

I think I'll be going with .002 across the board.

I guess we shall find out how things end up.