true,but with the available coatings it is becoming almost standard nowadays.i still want to get there faster than the other guy.

 

So what advantage would their be to the 3.8L stroker over a sleeved 3.8L motor?

 

long stroke motors make better mid-range torque compared to similiar displacement big bore motors.i prefer a awesome torque curve over peak h.p. anyday.it is more useable power unless you want to redline constantly.if you are mainly street give up the rpm dreams and concentrate on a fat torque curve and you will be much happier with the end product.

 

You have a very good question James, as mentioned shorter stroke and lighter components lead to an engine that can rev higher, but with our engines(VQ35) and a stroker kit (especially our GTM 3.8L) it isn't going to be limiting how high you can rev the engine since most people stay under 8,000 rpm anyway.

Bearings, piston, and thrust washer coatings are all very good idea for a high rev application. Valve train is a very important factor and a big cam is going to be a must to make some good top end power, if that is what you are after.

Cost wise, it is about the same to go with a sleeved short block with a 100mm bore or our 3.8L stroker short block, price difference is less than a couple of hundred dollars.

In an unsleeved engine, you are going to have much better heat dissipation than a sleeved engine due to the heat transfer properties of aluminum vs iron. Although with significant upgrades to the cooling system (including a GTM 82mm radiator) we were able to keep coolant temps under 90 degrees Celsius on a 4.2L stroked and sleeved engine that was being drifted on a road course all day, keep in mind while drifting airflow to the radiator is minimal so this was very impressive.

At the end of the day it boils down to what you want, me? I wanted the best of both worlds, So I went with the 3.8L stroker crank (87mm stroke) and sleeved my engine with a 100mm bore which gave me a 4.1L engine that can still rev high. I also added into the mix a set of our GTM Stage 3 cams (282's) and Stage 3 heads, since I will be revving my car to 8,000 rpm so we can see what it does For a bit of safety I also added a Nismo oil pump to the build so I can rev the motor high for years to come

We have three 3.8L stroker engines coming out of our shop between now and the next few months, including my G35, so this should help give you more information on the characteristics of a 3.8L stroker engine.

Here are a couple of pictures of our GTM 82mm Competition Radiator:

Hope this help,

-George
GT Motorsports

 

I remember I was talking to George@GTM a while back about the setup he is running on his G35. He is running a 3.8L stroked motor with bored-out sleeve, which brings the total displacement 4.15. Although the cost for this setup is way up there, it seems like this would be a fantastic compromise for revs and midrange torque.

edit: wow, i totally missed George's post. internet pwns me i guess.

 

That radiator is awesome. The welds are really beautiful :tear:

George. In regards to your heads, what kind of valve, shims, and springs are you running?

 

I have our GTM Stage 3 heads which come with the following compenents:

GTM Valve Springs (single)
GTM Exhaust and Intake Valves 1mm oversize
GTM Ti retainers
GTM Keepers
etc.

-George
GT Motorsports

 

Is the 3.8 stroker around 5k? How do you figure it is as much as a sleeved 100mm piston motor when sleeves are around 1k. I know there is more machining with the sleeves, but not thousands of dollars.

 

James You don't want a stroker motor!

All your questions will be answered when I give you a ride in my car. ALL!!

Save your self some $$$
... Go with Pistons, Rods, and Cams... Thats ALL you need!

 

Has anyone read or heard of cracked sleeves yet? The failures I have heard of were due to other components failing first like rods.

 

+1 for a street car that's what you need.sleeves and stroker under 550 hp are more for bragging.if you have loose change then go for it,otherwise you will just be another victim of over build.look at the unsleeved big numbers posted and you will see sleeves are more sales than need.btwy smaller pistons will rev faster than big bore,heavier pistons.

 

+100

 

Berto, aren't you sleeved?

 

Yup-but think back to September 06' (when I built) and it was the "thing to do" over 550whp, now its not needed in 99% of builds. Many 700+whp stock sleeve cars. Community has progressed

 

That is true. I did a lot of reading over your thread before I sent my own car off. Its crazy how things have changed in 18 months.

At any rate, knowing you're driving habits and style, if you were to do it all over again, would you instead go with a setup with a built (but unsleeved) bottom end? It still seems to me like a lot of people are still doing sleeves, I know MaximumsportZ has the Dartons on his car.

 

I would still sleeve, but thats because people like me need extra "strength" and we stil have issues Plus-dont let the original build #"s fool you, thats just me playing nice.

 

I've always wondered about those original numbers Are you at stock bore with your sleeves? If so, why didnt you decide to do overbore?

Anyways, all this built motor stuff is a super long way off for me, because at the moment school is kicking my ***. But, I do like learning stuff like this regardless of when I'll be able to get the work done.

 

Stock bore-numbers are legit, but no where near whats capable. Who knows what it would have done....

 

Great thread Jamez. Im learning too

 

Sorry man, I'm a little unclear on your setup. Are you running stock bore, or are you overbored with sleeves to 3.8L?