2.4l 7bolt

DSMinn0vati0ns · 12-27-2007, 07:08 PM

this winter i plan on doing motor work to my 2g and was thinking about making it a stroker. however i am a newb when it comes to building an engine so try and bare with me. i will not be putting this together but my local shop will be.

was thinking about purchasing a stroker kit from extremepsi and starting from there.. cleavit bearings/ balance shaft removal.. etc. after building the block would it be ok to slap on the stock head and make decent power with high boost? or are stroker motors not meant for the hi amounts of boost, and will need the head to be upgraded to get more flow?

looking for some basics and directions in what i will need to buy to complete this build.. help me out please? and sorry for my newbness as i tend to learn this stuff

Savage Talon · 12-27-2007, 07:23 PM

If you are using your 7 bolt 2.0 block and put a (stroker)100mm 7 bolt crank in it that will be a 2.3. If you want a 7 bolt 2.4 you will need a 2.4 sohc block and crank.

DSMinn0vati0ns · 12-28-2007, 06:13 AM

ok so def. going with the 2.3.. however i have been looking at slowboys stroker kits and was wondering what stage to go with.. either 2 or 3 im thinking? also what is a good compression ratio to run on stroker kits?

kingjust · 12-28-2007, 06:45 AM

Depends on the power you're wanting to make! I've got the stage 1 or 2 I don't know. If you got the dough, check FFWD Connections website, he makes some killer strokers. Also, He has rotating assemblies if you plan on doing it yourself. But with slow boy, just pick the right parts, for instance: If you plan on making over 600 "wheel" HP, upgrade the rods to an I or A beam style, or Pauters X beam. They are rated to hold alot more power. Preferably an eagle chromoly 100mm crank is in order if you are going to be racing often, but a refurb will do fine, IMO. Pistons are up to you, and with the compression I would go no higher than 8.8 or 9. If you have a good tuner you could do the 9:1, if you're doing the tuning and are ok, with say DSMLink or AEM, go for the lower compression... trying at all cost to stay away from the dreaded knock, and a higher comp. ratio will inhibit it, not drastically, but you better be able to tune that puppy pretty tight!

Another big thing to consider is that your engine is not an XL Hoover vacuum, wanting more air. So build your head accordingly, the benefits of a built head is well worth more than buying an expensive ass turbo!

KJ

TunaTalon · 12-28-2007, 07:05 AM

Yes some head porting is in order. The stroker may have more displacement than the 2.0L, but with the same intake tract it can make no more horsepower.

If you’re going stroker for more low end torque then higher compression ratio pistons are called for. The higher compression ratio will give more off boost torque.

Caution, caution on the use of “high strength” pistons and rods. Stronger usually means heavier and strokers are more sensitive to reciprocating mass than the 2.0L. Lighter is better, at least until they break.

Consider ACL main bearings as they can be tri-metal and designed with late model thrust bearings. (Mitsubishi 4G63 4G64 Bearings with Thrusts
)

If you don’t remove the balance shafts then be sure to replace their bearings.

If you feel the need to learn more of the technical details, and have a high threshold of boredom, then please see my StrokeOrNot document at http://www.kidzuku.com/StrokeOrNot.pdf)

DSMinn0vati0ns · 12-28-2007, 05:35 PM

wow lots of good info guys.. thanks!.. so basically im not gonna be able to slap on the stock head and make good numbers? or even have it flow good?

fourreGsixty3 · 01-06-2008, 06:41 PM

I'd stay away from Pauter's they are heavy for rod's. Crower or Eagle are good choices.

I do believe TunaTalon that ACL stopped making tri-metal's awhile ago...unless they have started up again with them.

To the OP: I'd say you might gain some power (but not nearly as much as if you had the head ported well), but what is the point of doing just the bottom end which increases air flow 20% or so, and not port your head to help flow the extra air that is being pulled in. Its like having a GT40 with a stock 1G MAF...it just doesn't make sense not to go all the way...or don't do any of it.

TunaTalon · 01-07-2008, 09:09 AM

Quote:

Originally Posted by fourreGsixty3

I'd stay away from Pauter's they are heavy for rod's. Crower or Eagle are good choices.

I do believe TunaTalon that ACL stopped making tri-metal's awhile ago...unless they have started up again with them.

To the OP: I'd say you might gain some power (but not nearly as much as if you had the head ported well), but what is the point of doing just the bottom end which increases air flow 20% or so, and not port your head to help flow the extra air that is being pulled in. Its like having a GT40 with a stock 1G MAF...it just doesn't make sense not to go all the way...or don't do any of it.

The ACL site I referenced in post 5 above still shows Tir-Metal bearings in the race series of bearings. Are you maybe thinking about Clevite. Clevite stopped making Tri-metal bearings just before my stroker research in 2005. However, this morning Google shows many sources for Clevite Tri-metal bearings.

+1 for porting, and upgrading the exhaust and intercooler piping. More displacement will be of little help when breathing through the same straws.