2.4L Stroker 6 bolt 4G64 or G4CS (6 bolt) block

[Chris Andrews]

I'm one of the few that have built a stroker on the 63 block and the 64 block.   I have posted a link to the 63 stroker a long time ago in this forum...

Now the 64:

- 90-91 Hyundai Sonata 2.4 block + crank (Mitsu crank p/n MD080691)
 
Mitsu 6 bolt 64s are quite rare in Canada, but if you want to see what cars had them, try http://www.roadraceengineering.com/mitsumotorapplications.htm

- 87mm head gasket MD189436 or Cometic MLS headgasket
- custom pistons ($860) (off the shelf from http://www.magnusmotorsports.com)
FYI - ALL 63/64 strokers require custom forged pistons.  No, I won't get into why here......
- 64 DOHC timing belt MD182292
- 64 intake cam gear MD189399 (or adjustable cam gear)
- 63 exhaust cam gear...yes its true... see:

note the rusty old 63 exhaust cam gear, and the shiney 64 intake (new hotness)  and the marks LINE RIGHT UP.

- knock sensor screws right onto the rear BS phase check plug (or have a bung machined in the exact right spot...)
- two small holes need to be drilled into the deck block
 
  (that might be optional)
- machine in oil jets (most likely optional with forged pistons...)
   the machine shop will need a 63 block as a template, this step most likely costs $300 or less....

The block is 6mm higher, so certain things might need to be readjusted... for example my down pipe came into contact with the oil pan.   I fixed it by adding a spacer.  Yes, the hood still fits.

I think thats it.  If I've left anything out, try to use common sense....

[DISCLAIMER]
Obviously, consult an experienced engine builder on how to do a project of this magnitude correctly.  If you spend lots of money and throw it down the drain because of your own ignorance, don't come crying to me.
[/DISCLAIMER]

What is the best way to stroke?

63 is the cheapest, but the block needs to be clearanced.....
64 is the coolest.  

[Jerry Hong]

Just to add for the 2g guys, your 2g block stuff don't fit! You should have a 1g block ready to salvage the parts. ie: oil casing, oil adapter, tensioner pullies. You also have to use the 1g water pump, and then you need to cut/grind the 2g motor mount.

[KevinBuckham]

Chris,

Above you mention using a 4G64 Intake cam gear, and the stock 4G63 Exhaust cam gear.  Other web pages recommend either using both cam gears from a 4G64 OR using the stock gears advancing the timing by 1/2 a tooth.

I have a feeling that I don't really understand what is going on here.  Why are you using a stock exhaust gear, while others are advancing the timing on this gear?  Why shouldn't both gears be advanced by the same amount to make up for the 6mm deck height difference?

I'm not insinuating you are wrong, I just don't really understand and I want to get my cams roughly "straight up" for the break-in.  And I am guessing that some reference sites I am looking at are wrong.

Finally do you know roughly how many degrees the 4G64 Intake gear differs from a stock gear?  If you don't know I will purchase a complete set of 4G64 gears and measure against stock so I can use my adjustable 4G63 cam gears.

Thanks!

[Mike Meron]

why not buy fidanzas and have the ability to run a larger cam than stock so you can havem more fun

[KevinBuckham]

The problem is that I have (or will have) adjustable cam gears on the car.  I just want a starting point that puts the cams roughly "straight up" on my 2.4.  When I have time later this year I will swing by Kinetic to do a bit of tuning, but for my first few months of racing I would like to have them roughly in the correct position.

I have read numerous boards and I have three different conflicting answers on what to do with the cam gears to get it right on a 2.4.  (Two theories seem plausible.)

Most believe that the intake and exhaust need to be different than stock, but Chris Andrews just used a 4G64 intake gear.  Chris knows what he is doing so I am taking him seriously - but I have some conflicting opinions from a couple of others that should know as well.

So far, it's all good as I only have a G4CS sitting on the floor, and no head or transmission (yet).

[Chris Andrews]

Well, why?   Just because.   Should I produce a wordy explanation because you don't trust me?  :laugh:

I'll provide a simple answer:  I had both 64 gears and the cams (teeth) WOULD NOT LINE UP with the belt (notches).  I had to advance or retard an uncomfortable amount, and in the end the engine didn't seem very happy with it.  Put the 63 on, and zwap!  like a glove............

I'd love to hear anybody's thoughts as to why this is the way it is........

Many people have done the hybrid, but few if any mention this problem.... but most people just buy adjustable cam gears, and then degree the cams,  and most likely are oblivious to the issue.

In the end, arm-chair theorys are no match for practical experience, and  the "just because" stands.  

[Mike Meron]

why not buy adjustable gears
just because :laugh:
actually the way chris is doing it works well when lobe centers are based on stock but as soon as a high lift cam is involved then degreeing and adj cam gears are the norm.