I believe that only the main bearings are the same between HR/VHR and VR38. But I cannot hands-on confirm this... its just what I "understand".

For the rod bearings, a HR/VHR should use 57mm big end bore, at .818" width.

VR38 should be 59mm big end bore, at .894" width.

Anyone correct me if this is incorrect.

And what kinda power would the short block hold?

As much as the stock sleeves will hold. I would say safe on those rods 700hp

Actually those k1 connecting rods are rated up to 900hp..

Hi ...
Following this build out of necessity... :-(

Just want to clarify things in my mind ...
I need to rebuild my motor.

I have stock block with an upgraded Stillen SC'r making 11.9 lbs boost along with 1000 lph injectors and other supporting goodies.
It dyno'd at 483whp and 378 tq.
First time down the track it cracked a piston or ??? Nothing came thru the side of the block.

Would like to keep as much of the mods already done but keep or up the power to the 550-600 range while keeping the reliability of the motor.

Definitely a Long Block (can send my motor) - but need advice / recommendation for the Compression Ratio ~ Pistons and Rods

9.0:1 or 10.0:1 ??? for the Supercharged motor.

All help greatly appreciated !

Many Thanks,

Good question!
Not sure which is the best route to go on built block SC but I can tell you with a built block and Stillen SC ur not gonna make even 500hp.

You should consult ur installer or tuner as that kit will not come close to putting the amount of stress required to pop a motor. Something most likely went wrong during install or tune.

U could build ur block and I believe a fellow member did the same going 10:1. He ended up selling the Stillen kit and now has a single turbo kit making nice numbers.

Yep may as well go 10:1 but if only 600 is your goal some standard forged 11:1 slugs may be your best bet. Think stock but stronger.

Sent from my HTCONE using Tapatalk

Thanks for the quick reply !!! Mucho Appreciado

It' definitely not a Stillen any more - just looks like one.
Upgraded everything imagineable.

There have been a lot more options available since I put the Stillen in a long time ago.
I do have a lot invested in the build and at the risk of throwing good money after bad ... I don't want to start all over again ... time and money and down time again.
It has been about 7 months in the build so far (I'm all patience'd out) and am at the point that I will be happy to get in to the 11's (I'm in the low 12's now)

Point me in the right direction utilizing what I already have ... Tired of waiting and just want to drive again.

But :-) send me the link to that Single Turbo just in case !!!

Thanks !
At this time 600 whp for me is practical ...

The Z's just don't seem to hook up as good as they should...
All that extra HP sometimes seems to go to waste at the track.

Open for more input !!!

ok if you are sure on sticking with the stillen then i would go with 11:1 so you won't lose any power since getting more air out of that charger is going to be hard. If you call voretch and do a core exchange on a V7 it will be a toss up between the 10:1 and 11:1 pistons. you lose horsepower every time you go down in compression ratio, but you lower cylinder pressure, so unless you can boost the engine more to make the power back(and then some) sticking with stronger pistons and the factory ratio is the way to go. This is especially important when dealing with an undersized blower because it can only push so much air. with the v7 you would be able to make up for going down to 10:1. I believe the v7 also has the larger higher speed bearings in it so it can be spun much faster, but is externally oiled so you would either need a pump and reservoir setup for it or tie it in to the engines oil circuit. the v7's compressor cover is a bit larger as well so no guaranty that it will fit without a little work. once you get to that size tho you are going to need additional cooling by the way of meth or redoing the intercooler piping. also if you havent relocated the MAF sensors already you should do that. the inlet pipe on the stillen kit is also very restrictive with the offset coupler going to a single 2.5" pipe( :wtf: stillen that is HALF of what the car had stock to breath through)

so to sum it up
if stillen v3: 11:1
if stillen v7 +upgrades: 10:1


or just go 10:1 sell your kit go turbo and you will have 600hp.

Also if you stick with it and have the piping re done the stillen intake manifold is garbage and should be used as boat anchor like it was designed, if you can use the factory manifold and an air to air inter cooler I guarantee you will gain power

Awesome ... Consider me thoroughly edu-ma-cated :tiphat: