Hello from Finland!

Dave · September 15, 2013, 09:45:11

Thanks

So you have what sounds like a pair of Garrett T04E copies & what we would call high octane 98 RON fuel.

Sounds like a 46 trim compressor.

Looking at it the compressor size looks good.

Turbine side looks to be a little big but it's not massive!

The turbo's are not the problem, you must have something holding this engine back.

It should really be making 500bhp on 1 bar of boost.

The Ravenz 4.0L made 600bhp / 670 lbs @ 3800rpm on 24 psi

Yours looks to be a better spec?

It's never going to make mega horse power but there should be lots & lots of torque until 5000 rpm where it will probably drop .

Dave · September 15, 2013, 10:37:20

Pete have you got a data log of your boost?

There is no way a 2933 cc engine should be able to out drag you like this!

The graph is power at the crank isn't it? or is it wheel figures?

puuhapete · September 15, 2013, 11:04:46

1.Pete have you got a data log of your boost? No

2.There is no way a 2933 cc engine should be able to out drag you like this!

3.The graph is power at the crank isn't it? or is it wheel figures? Engine not wheels (The calculated power on wheels)

I'll tell you that yet due to time constraints we do not adjust the ECU,(more cars) and something small improvement could get it through.

puuhapete · September 15, 2013, 19:58:17

I checked the intercooler flow and exhaust pressure. These were good.
The exhaust pressure was 1:1 with boost pressure.
I'll re-measurement of power yet, and we adjust ECU with the time, when we see the actual situation.

puuhapete · September 16, 2013, 05:54:01

I go works in the morning and I noticed that the manifold pressure gauge screen. At the same time I realized my mistake. Shoot-out boost "only" 1.3 bar no 1.8bar.
Because I have turned the meter needles read-1.0bar and now the pressure will rise 0.3 bar.
The reading should be 0.8 bar to 1.8 bar. The idea, therefore, was a break.

Now boost is 1.3bar and exhaust pressure 1,8bar

Dave · September 21, 2013, 10:42:17

Hello Pete

QuoteShoot-out boost "only" 1.3 bar no 1.8bar

That makes things a lot better but still shows problem.

QuoteNow boost is 1.3bar and exhaust pressure 1,8bar

Problem 1! That must be before the turbo I hope.

That will cause your hp to drop if the cam has close to STD over lap.

Anything over 5 psi difference I have found starts to show up as a torque drop.
What is the back pressure after the turbo?
Enlarging the wastegates may help, do you know there size?

It would be helpful if you could do one run at 1 bar.
On that run data log the boost pressure.

That run will show if the engine is simply hitting it's flow limits or if something is wrong with the tuning.

Good luck.

Dave

puuhapete · September 21, 2013, 11:47:07

Quote from: Dave on September 21, 2013, 10:42:17
Hello Pete

QuoteShoot-out boost "only" 1.3 bar no 1.8bar

That makes things a lot better but still shows problem.

QuoteNow boost is 1.3bar and exhaust pressure 1,8bar

Problem 1! That must be before the turbo I hope.

That will cause your hp to drop if the cam has close to STD over lap.

Anything over 5 psi difference I have found starts to show up as a torque drop.
What is the back pressure after the turbo?
Enlarging the wastegates may help, do you know there size?

It would be helpful if you could do one run at 1 bar.
On that run data log the boost pressure.

That run will show if the engine is simply hitting it's flow limits or if something is wrong with the tuning.

Good luck.

Dave

Yeah! It's before turbos. Small problem is ignition map because max about 20 degree to boost. We adjust this point the next power shoot test.

Dave · September 22, 2013, 08:59:46

Unless you have a problem Pete it looks like the turbo exhaust turbines are too big for the engine.

If you look at your results.

Black line is a STD 12V OHV doubled to show 1 bar of boost.

Red is yours at 1.3 bar.

You can see your engine spools up way too late to suit the torque curve of the engine.
An OHV 4.0L just dies after 4000 rpm.

You have lift at high rpm which shows you have improved the max flow of the engine but it's not enough to make up for the mid range you have lost which is the engines strong point.

Do a run at 1 bar boost & record the boost.

It's my opinion that if you are sure you can not get the turbo's to spool faster then the biggest improvement possible to the engine is using different turbo's.

The engine has the potential to make over 100 lbs more torque at the same boost than you have achieved so far.

puuhapete · September 22, 2013, 18:50:01

There has been a problem to get the RPM to enlarge this engine was stopped at 5500. Not good. Now, however, modified to get around very well.
Turbos are a bit like that when you buy cheap, do custom designs.
Maybe they are a bit lost somewhere in the area and I have to just accept it.
But after a week we will try to provide a better engine and search for the correct ignition advance.
A small harm came when one of the rocker broke up 1 cylinder. I had to put standard rocker arms now.
->

Thank you Dave good reference maps. It was interesting to compare the curves.

Dave · September 27, 2013, 23:21:26

Pete of course you need to check some things.

Make sure the waste gates are matched. (they both open up at the same time)
Are the waste gates leaking?

& so on.

But if the turbos will not spool up any faster then you will need to either change the turbo's or use something to increase exhaust flow like a bit of NOS to get the best from the engine.

The turbo's you used are based on an old design & have to be matched closely to an engines exhaust output which looks to be where you have the problem. Hence the whole hybrid turbo industry!

The far more modern GT's work far better with a wider range of engines so are much easier to get right.

This is what I think you should be aiming for & is perfectly possible.

You can see you also lost a lot of bottom end power compared to a STD engine.

Another sign of a turbo mis-match or problem.

If you fitted a pair of GT2860RS's with the .64 exhaust housings you would achieve very close to the above graph possibly better.

China copy's would do it too but you take your chance with the reliabilty.

Best of luck.

puuhapete · October 01, 2013, 16:02:57

I installed a std rockers and power decreased to 460hp.After ignition control after the power was 487.4 hp / 677nm
I added the boost pressure 0.1bar, Power did not increase at all so we left it there.
I need to study if I exhaust back pressure changes below. Turbos next examined if the exhaust system is not oppressive.
But as you can see 2500rpm is now about 100nm more torque std rocker arm

Dave · October 05, 2013, 10:39:18

Hi Pete

Well you have almost gained all your off boost power back which is good.

Tell me how does your design of rockers compare to STD? (What is the ratio?)

Also what is the spec of the camshaft you are using?

Looking at the new graph you talk about back pressure however it looks like it's showing a boost plot.
Can you explain?

Your engine may make less peak power but I think it will be far better to drive now as you have recovered a lot of low down power.

How does it feel???

puuhapete · October 05, 2013, 12:07:11

Hi Dave!
This camshaft has been carried out special CompCams, they take into account that my rocker 1.76 "while making it.

I meant that the exhaust pressure get up than that boost pressure. It not can be seen in that graph.

Well, i missing high power up but I do not really know which one better. Perhaps it is felt more strongly when the power came later.

Dave · October 05, 2013, 12:24:19

O.K Thanks

Am I right in saying the STD rocker ratio is 1.46:1?

1.46 vrs 1.76 !

I don't have time right now to study your cam spec maybe in a few days.

You are saying the plot on the graph is boost pressure then?

What was the back pressure figures?

puuhapete · October 05, 2013, 12:59:54

Quote from: Dave on October 05, 2013, 12:24:19

O.K Thanks

Am I right in saying the STD rocker ratio is 1.46:1?

1.46 vrs 1.76 !

I don't have time right now to study your cam spec maybe in a few days.

You are saying the plot on the graph is boost pressure then?

What was the back pressure figures?

Yes, 1.46 is std and graph is boost pressure.
The exact map is not the exhaust pressure, but 1.25 boost and exhaust 1.8 bar

Dave · October 06, 2013, 11:03:02

Then your defiantly boosting too late to the suit power characteristics of the engine for best results.

You also have too much back pressure which is causing the torque to drop faster than it should which robs you of some HP.

By fitting the STD rockers you reduced the cam duration which of course reduced lift & changed the timing slightly.
Made a huge difference to your low end power which shows the cam is not particulary suited to your engine either.

Anyway the big one is boost get it to make boost earlier & it will mask the other two problems to give a good wide torque plot. It should pull 600lbs of torque with ease & be a fantastic road car.

Just my opinion mate but that to me looks the way to get the best out of the engine.

puuhapete · January 05, 2014, 18:24:04

Happy New Year here. I hope in a better direction for myself. Last year ended while the engine breakdown. Now, went across the crankshaft. Does not this ever stop thinking.

pic.

Lemon-Ade · January 05, 2014, 19:04:33

Gutted for you mate

capri v8 driver · January 05, 2014, 20:27:07

I did edit the picture for you.

Breaking a crankshaft happened twice to me with the v8 small block with nitro, in both case the block started to crack and twist first, than the crank broke.

puuhapete · January 05, 2014, 23:04:05

Quote from: capri v8 driver on January 05, 2014, 20:27:07
I did edit the picture for you.

Breaking a crankshaft happened twice to me with the v8 small block with nitro, in both case the block started to crack and twist first, than the crank broke.

Thank you! I have only used the phone and I did not get pictures of the view. I did not see any cracks in the block.

Grey · January 07, 2014, 12:30:38

Damn!
Sorry to see that. Guess the 4.0 crank is having a really heavy job compared to the 2.9ers!

puuhapete · January 07, 2014, 15:30:07

I thought if put BOB crankshaft and new pistons. The volume would decrease 3.5 L, but it might be more durable.
Do you have any information about a boa or bob crankshaft stronger than the 2.4/2.9 12v?

capri v8 driver · January 07, 2014, 20:25:46

I don't think the 2.9 12v is weaker or stronger than the cosworth crank. the 24v crankshaft has modified counterweight (more weight in the center) and a double sprocket to drive the duplex (double row) timing chain.

puuhapete · January 08, 2014, 07:24:21

I noticed yesterday that the balance in the same location as the 4.0 12v.
Top view of a crank 969M6303 AA

capri v8 driver · January 08, 2014, 08:48:33

Both cranks are internal balanced, so they have the weight in the same location.

Dave · January 17, 2014, 01:17:37

Oh Pete I am really sorry to see this after you did such a good job of that bottom end!

I did mention before that there is a known problem with these STD 4.0L cranks twisting!

But as yours is a stroker I assumed you was running some custom crank from the states.

STD 4.0L cranks start to twist around 550 ft/lbs.

First signs is a vibration that gets worse, next they chew up the main bearings & that's usually the end of it. Never seen one go as bad as yours before!

Strangely even though the 24V crank is basically the same the reduced stroke seems to make a massive difference. A 24V crank is far stronger!

Again you have reached a cross roads & been very unlucky!

Andres · January 17, 2014, 18:41:45

Hey

My cosworth bob engine runs 2,2 bar boost with 71,5mm holset pro52 turbo.
We dyno this engine 950bhp and 1060nm. Engine runs good and no problems...
Use BOB crank and it´s works fine.

Best: Andres from Estonia

capri v8 driver · January 17, 2014, 20:18:15

QuoteWe dyno this engine 950bhp and 1060nm.

We are waiting when it breaks the 1000 hp mark

puuhapete · January 18, 2014, 07:08:08

Quote from: Andres on January 17, 2014, 18:41:45
Hey

My cosworth bob engine runs 2,2 bar boost with 71,5mm holset pro52 turbo.
We dyno this engine 950bhp and 1060nm. Engine runs good and no problems...
Use BOB crank and it´s works fine.

Best: Andres from Estonia

Hi Andreas!
Very nice. I know you taunus.You assume the hard power and we talked about that one person you probably know, "TVR" in Finland.
The block has remained at you in great condition.In this living proof of how strong the crank is 24v.

puuhapete · January 18, 2014, 07:20:14

I heard from one problem that might affect me when I make the machine a stroke of 72mm and the connecting rod as long as 6.00. "This ratio would be 2.1.
This would mean that the piston would be more tdc position. What does this work?
At low rpm, the plane lost power, but the power of big rounds is good. True or false?
I'll do it, however, another smaller problem is the piston / connecting rod are heavy compared to the 2.9 24 engine. With balancing will probably have to increase the weight of
I do it anyway.