Ive already got the L19s as well. Will it be obvious to the machinist what changes to make when using the HR gaskets? Head gasket is the LAST place to skimp out but if the L19s are what makes the difference then i should be ok.

 

Yeah, i seriously recommend HR it can hold the power (we dont kno the limit, north of 800+ probably), and more efficient cooling!! the bolts/studs is what determines if u have head lift or not, so your perfect with L19's.

No the machinist wont know what to do as far as modifying, the HR gasket drops in just like anyother gasket, you dont have to modify anything to make the gasket fit, but you do have to increase the flow to the head n gasket.

JWT describes exactly what to do, read this: http://www.jimwolftechnology.com/wol...HEAD_BOLTS.pdf

and they also compare the HR with the DE gaskets and their differences.

ur welcome lol

 

You guys calculate a % for drivetrain loss?

So if I dyno a stock Z and get 220 (average) at the wheels and the factory says its 287 at the crank then I've lost 67 horsepower or roughly 23% of my power.

If I then build the bottom end and turbo it and dyno at 769whp how does my % loss go down to 15% with a loss of 131hp?

Assuming a new clutch, lighter rods and pistons etc the system should be more efficient than stock therefore it should also have less parasitic loss. It should lose less than the original 67hp lost in the first dyno, not more.

The same system is being used yet we are calculating more loss at a higher output? Makes no sense.


Am I missing something?

769whp + 67hp loss = 836hp = 8% loss

 

Like he said, its an estimate. Not everyone has the money or even the possibility to put a motor on a dyno to measure the crank HP. so all one can do is guesstimate.

 

Yep. Rented my block plate from Shariff when I had mine bored and honed. My machine shop said that our blocks were very good as it wasn't off by much without the block plate, but he was glad that there was one available to use.

 

OMG wow.

The only way to measure actual engine brake horsepower (thats the horsepower at the flywheel) is to have the engine on an engine dyno (very expensive).

The power that actually matters is the power hitting the ground (rear wheel horsepower, for rear wheel drive car).

The concesus is that the 6spd's generally lose about 15% of power through the drivetrain (this comes from rotating the flywheel, clutch, transmission, driveshaft, halfshafts, wheels, etc. Also from friction in the gears of the trans and diff. Also from angle changes in the driveshaft).

So My car made 769 rear wheel horspower. 769/.85 = 904 horsepower at the flywheel (again its making an assumption that the car is using 15% of the power in the drivetrain which is pretty much a universal agreement).

Tom

 

We get your calculation methods Thom00, we just disagree with drivetrain losses increasing. It takes 60-70 horses to drive the wheels, losses with all things in the drivetrain unchanged should remain constant. Regardless good job on building some serious power.

 

I've often wondered the same thing.......but others have shown (not on here) it is not a constant. I don't think it correlates to 15% across the board, but it is the accepted calculation.

Tom

 

Armlocker, watch-out with the decking of the block. Sure its is a great thing to do but the way the engine is made doesn't allow for much material to be removed. It has the timing cover that fits only tight clearances, so if you get an agressive deck now and then have to rebuild in the future and have warpage you could have a problem.

 

ummmmm, don't know about your calculations. Once you start adding power, the loss does not remain a constant number. It is a percentage that most likely will actually increase the more power you are making. It isn't something that remains constant like being a flat 60 hp to turn the rear wheels.... it is a % of power that is lost throughout the drivetrain from gears, friction, heat, ect.

Does it make sense that my Honda fit makes 117 bhp but puts down 95 whp? Why does it take my honda only 22 hp to turn the wheels and it takes my Z, upwards of 60 or more? Is my honda just that more efficient? If you look at the 22 vs 60 hp numbers, one could make the argument that it is. But if you look at the % lost, the same argument could not be made

 

My opinion is to get the new cosworth or HKS. While I agree the HR is decent HG, I personally think the stopper style gaskets have a more proven track record.

Sharif will ship the plate to you. I live in MN and had him ship to my machine shop

 

For best results on a shortblock, contact a shop that builds engines (better if they have experience with VQs) tell them what your whp goals are and them let them tell you what components to get and what needs to be done.

I learned the hard way on this. The best results are found when you let the engine builders do what they do best. The steps are simple:

1. Reseach, contact and then decide on a shop
2. Show up with a deposit and drop off the block
3. Show up with final payment and take home the assembled shortblock with a full spec sheet

 

In addition to paying two or three times the amount compared to having done it oneself.

What ever happened to car enthusiast working on their own cars, and building their own engines. Gotta start somewhere. Most ofcourse have the money to just let a good shop do it all and build anything, but whats the fun in that?

some however are not mechanically inclined and just want to do a build, thats understandable but if someone wants to do the work themselves, nothing wrong with them being a newb asking all the questions and doing research.

 

Actually it does make sense why a FWD/Front Engine car will generally lose less power through the drivetrain. It doesn't have a differential case and the additional gears, shafts and weight losses associated with sending the power away from the engine's mounting location. Not to mention it doesn't require the "heft" that a car with 2-3 times the power will need. But I don't want to argue and steal this guy's thread. We will just have to agree to disagree.

 

Armlocker, on the head gasket do your research...I don't think its worth the additional hassle for an NA motor. The additional cooling capacity is nice but the engine and stock raditor hold up pretty well with out FI. However, I would suggest putting an oil cooler on with the money you save on mod'ing for the HR head gasket.

 

I didnt mention it before but it will be a FI build. I'll do my head gasket research. Just wanted to get more detailed on the crank/block specifics with this thread.

Are there any actual machinists on these boards that do engine work for a living?

 

so why did my stratus R/T coupe (FWD, auto) rated at 200bhp, only put down 142 whp. we are now back near 60 hp just to turn the wheels. Same fwd auto configuration as my honda, but takes 2.5-3 times the power just to turn the wheels.

It works on a percentage, not a constant number.

 

I got ya, i have seen a couple of threads on the proceedure and it doesn't seem too hard, but I don't like the idea of modifying the head if there is no problem with cooling showing. As far as the short-block is concerned I can't think of much to watch out for if your not stroking the motor. Just take your time on the installation and the internals.

 

Do you really think a Stratus is as efficent as a Honda.

 

Well quite honestly, on an auto, the Tourque converter means as much as the trans itselft......a "loose converter" and a "tight converter" will have DRASTIC variations on whp...

Tom