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Project Rb31dett. The Development Of My Open Deck Rb Engine And The Quest For More Torque!


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Sounds good!! lol...a phone call to Jim may be worth while either way - he likes to talk clutchs and he may be able to offer some advice on what caused the faliure or your proposed selection.

The drivability was why i made the suggestion - i hadn't heard about the welding issue (bit worried about mine now :unsure: )

I have a theory about my clutch failure... If a disc is in backwards I'd have to pull the pressure plate further to get it to dis-engage. Over time this has probably damaged the spring.

I don't think welding the clutch would be too much of an issue really for most. The car in question was around 800hp at the crank, and I think it was a 1300kg ATS carbon twin plate.

Thanks for the heads up Marko. Clutch purchase now put on hold till next week I think.

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Further investigation has revealed that I had probably exceeded the maximum torque rating of the gmax. My last dyno torque figures was 574mn and I am pretty sure I am exceeding that now with the most recent engine changes. It had probably been slipping a little all the time, and its now only getting bad now that Ive given it a hard time too often.

I have decided to go with the exeedy twin carbon D clutch. Hopefully it will be here in a few weeks.... I get withdrawls from not driving the car after a week so its going to be a hard wait!

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  • 4 months later...

Updates...

Well the new exedy carbon D clutch makes the car simply awesome to drive now. I've driven the Nismo twin plates, and I think the carbon D is quite a step up on it for drivability as well as improved response due to reduced inertia. It doesn't get grabby if you have to ride the clutch a little should you be reversing up a steep driveway.

I've been playing around with cam timing again, and logging the results as I go. The best response setup with the GTRS's I had produced 1.1 kg/cm boost at 3600 RPM. That's in 2nd gear on the road, not a dyno being leaned on with the roller speed locked.

That same cam timing also had quite poor top end past 6500 though. I don't know what RPM would have been required to get to 1.7kg/cm as I am doing my cam experiemnts with the boost controller off. This way I can better see the effects of back pressure and exhaust flow changes in the logs. I am very seriously considering a HKS step 1 Vcam setup for the next engine to get a best of both worlds setup.

The Apexi 3.5 bar map sensor has also helped get the tune more responsive as it reacts much faster than the GM or standard apexi sensors. Lack of atmospheric compensation is a bitch though. When I drive up a near by range it runs quite rich as the pressure change moves the load PIM value about 400. (not sure if ive mentioned this before)...

I am driving the car most days for work still. The engine has about 23,000km on it now. I've had to change back to the much quieter nismo exhaust as the trust single muffler titanium setup tested over 126db. Fortunatly not tested by police! Its nice being able to talk to again passengers too.

I've been sidetracked with work, but the version 3 engine parts collection is slowly coming together.

An 024u block arrived 2 days ago so I've got to take some time out to do a final measure up before ordering my new sleeve configuration. The new sleeves are a stepped OD configuration to allow the cylinder wall thickness to be massively increased. Thicker at the top, then thinner as the sleeve is pressed into the block where it passes by the main oil gallery in the block.

90mm bore is the maximum size with a 3.65mm wall thickness still retained. Compare that to a 87mm bore in a standard block you only have 2.5mm cylinder thickness at the thinnest area. The version 3 engine will first have an 89mm bore giving me the ability for 2 oversize cuts later.

The new sleeve setup also converts the block to a wet sleeve design, which will massively help with heat management. While my engine cruises on the nismo thermostat at 68 degrees most of the time and oil temps are around 10-11 degrees warmer, when I give the engine a hard time the oil temps do get higher faster than I'd like. I put this down to the partial grout fill in the block, as more cylinder heat is being taken away by oil than by coolant.

I've got a full counterweight nitto 90mm crank with SR20 journals and a set of nitto sr20 ibeams for internals for the V3 engien. With the 89mm bore that makes 3360cc the minimum capacity and a max of 3436cc with a 90mm bore.

Im torn as to weather to use the GTX2860r's or a GTX40-42 on the version 3 engine. I do like the idea of keeping my near stock looking appearance... Be sure I will start a new thread for this when it starts going together.

Cheers,

Ian

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Updates...

Well the new exedy carbon D clutch makes the car simply awesome to drive now. I've driven the Nismo twin plates, and I think the carbon D is quite a step up on it for drivability as well as improved response due to reduced inertia. It doesn't get grabby if you have to ride the clutch a little should you be reversing up a steep driveway.

I've been playing around with cam timing again, and logging the results as I go. The best response setup with the GTRS's I had produced 1.1 kg/cm boost at 3600 RPM. That's in 2nd gear on the road, not a dyno being leaned on with the roller speed locked.

That same cam timing also had quite poor top end past 6500 though. I don't know what RPM would have been required to get to 1.7kg/cm as I am doing my cam experiemnts with the boost controller off. This way I can better see the effects of back pressure and exhaust flow changes in the logs. I am very seriously considering a HKS step 1 Vcam setup for the next engine to get a best of both worlds setup.

The Apexi 3.5 bar map sensor has also helped get the tune more responsive as it reacts much faster than the GM or standard apexi sensors. Lack of atmospheric compensation is a bitch though. When I drive up a near by range it runs quite rich as the pressure change moves the load PIM value about 400. (not sure if ive mentioned this before)...

I am driving the car most days for work still. The engine has about 23,000km on it now. I've had to change back to the much quieter nismo exhaust as the trust single muffler titanium setup tested over 126db. Fortunatly not tested by police! Its nice being able to talk to again passengers too.

I've been sidetracked with work, but the version 3 engine parts collection is slowly coming together.

An 024u block arrived 2 days ago so I've got to take some time out to do a final measure up before ordering my new sleeve configuration. The new sleeves are a stepped OD configuration to allow the cylinder wall thickness to be massively increased. Thicker at the top, then thinner as the sleeve is pressed into the block where it passes by the main oil gallery in the block.

90mm bore is the maximum size with a 3.65mm wall thickness still retained. Compare that to a 87mm bore in a standard block you only have 2.5mm cylinder thickness at the thinnest area. The version 3 engine will first have an 89mm bore giving me the ability for 2 oversize cuts later.

The new sleeve setup also converts the block to a wet sleeve design, which will massively help with heat management. While my engine cruises on the nismo thermostat at 68 degrees most of the time and oil temps are around 10-11 degrees warmer, when I give the engine a hard time the oil temps do get higher faster than I'd like. I put this down to the partial grout fill in the block, as more cylinder heat is being taken away by oil than by coolant.

I've got a full counterweight nitto 90mm crank with SR20 journals and a set of nitto sr20 ibeams for internals for the V3 engien. With the 89mm bore that makes 3360cc the minimum capacity and a max of 3436cc with a 90mm bore.

Im torn as to weather to use the GTX2860r's or a GTX40-42 on the version 3 engine. I do like the idea of keeping my near stock looking appearance... Be sure I will start a new thread for this when it starts going together.

Cheers,

Ian

sounds awesome!!

I reckon the 2860 would be too small on that capacity. Hopefully by that time more results are about!

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Updates...

Well the new exedy carbon D clutch makes the car simply awesome to drive now. I've driven the Nismo twin plates, and I think the carbon D is quite a step up on it for drivability as well as improved response due to reduced inertia. It doesn't get grabby if you have to ride the clutch a little should you be reversing up a steep driveway.

I've been playing around with cam timing again, and logging the results as I go. The best response setup with the GTRS's I had produced 1.1 kg/cm boost at 3600 RPM. That's in 2nd gear on the road, not a dyno being leaned on with the roller speed locked.

That same cam timing also had quite poor top end past 6500 though. I don't know what RPM would have been required to get to 1.7kg/cm as I am doing my cam experiemnts with the boost controller off. This way I can better see the effects of back pressure and exhaust flow changes in the logs. I am very seriously considering a HKS step 1 Vcam setup for the next engine to get a best of both worlds setup.

The Apexi 3.5 bar map sensor has also helped get the tune more responsive as it reacts much faster than the GM or standard apexi sensors. Lack of atmospheric compensation is a bitch though. When I drive up a near by range it runs quite rich as the pressure change moves the load PIM value about 400. (not sure if ive mentioned this before)...

I am driving the car most days for work still. The engine has about 23,000km on it now. I've had to change back to the much quieter nismo exhaust as the trust single muffler titanium setup tested over 126db. Fortunatly not tested by police! Its nice being able to talk to again passengers too.

I've been sidetracked with work, but the version 3 engine parts collection is slowly coming together.

An 024u block arrived 2 days ago so I've got to take some time out to do a final measure up before ordering my new sleeve configuration. The new sleeves are a stepped OD configuration to allow the cylinder wall thickness to be massively increased. Thicker at the top, then thinner as the sleeve is pressed into the block where it passes by the main oil gallery in the block.

90mm bore is the maximum size with a 3.65mm wall thickness still retained. Compare that to a 87mm bore in a standard block you only have 2.5mm cylinder thickness at the thinnest area. The version 3 engine will first have an 89mm bore giving me the ability for 2 oversize cuts later.

The new sleeve setup also converts the block to a wet sleeve design, which will massively help with heat management. While my engine cruises on the nismo thermostat at 68 degrees most of the time and oil temps are around 10-11 degrees warmer, when I give the engine a hard time the oil temps do get higher faster than I'd like. I put this down to the partial grout fill in the block, as more cylinder heat is being taken away by oil than by coolant.

I've got a full counterweight nitto 90mm crank with SR20 journals and a set of nitto sr20 ibeams for internals for the V3 engien. With the 89mm bore that makes 3360cc the minimum capacity and a max of 3436cc with a 90mm bore.

Im torn as to weather to use the GTX2860r's or a GTX40-42 on the version 3 engine. I do like the idea of keeping my near stock looking appearance... Be sure I will start a new thread for this when it starts going together.

Cheers,

Ian

Exactly what i found with the carbon D - glad i didn't steer you in the wrong direction. I've had Jim Berry up the clamping force on mine, so i'll let you know if i still get slippage on steep driveways.

Engine mark 3 sounds awesome. Can't wait!!!

Twin GTX2867's might be alright - you would loose some potentional up the top end, but would be pretty snappy in the low/mid-range with that capacity

Edited by wedge_r34gtr
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Updates...

Well the new exedy carbon D clutch makes the car simply awesome to drive now. I've driven the Nismo twin plates, and I think the carbon D is quite a step up on it for drivability as well as improved response due to reduced inertia. It doesn't get grabby if you have to ride the clutch a little should you be reversing up a steep driveway.

I've been playing around with cam timing again, and logging the results as I go. The best response setup with the GTRS's I had produced 1.1 kg/cm boost at 3600 RPM. That's in 2nd gear on the road, not a dyno being leaned on with the roller speed locked.

That same cam timing also had quite poor top end past 6500 though. I don't know what RPM would have been required to get to 1.7kg/cm as I am doing my cam experiemnts with the boost controller off. This way I can better see the effects of back pressure and exhaust flow changes in the logs. I am very seriously considering a HKS step 1 Vcam setup for the next engine to get a best of both worlds setup.

The Apexi 3.5 bar map sensor has also helped get the tune more responsive as it reacts much faster than the GM or standard apexi sensors. Lack of atmospheric compensation is a bitch though. When I drive up a near by range it runs quite rich as the pressure change moves the load PIM value about 400. (not sure if ive mentioned this before)...

I am driving the car most days for work still. The engine has about 23,000km on it now. I've had to change back to the much quieter nismo exhaust as the trust single muffler titanium setup tested over 126db. Fortunatly not tested by police! Its nice being able to talk to again passengers too.

I've been sidetracked with work, but the version 3 engine parts collection is slowly coming together.

An 024u block arrived 2 days ago so I've got to take some time out to do a final measure up before ordering my new sleeve configuration. The new sleeves are a stepped OD configuration to allow the cylinder wall thickness to be massively increased. Thicker at the top, then thinner as the sleeve is pressed into the block where it passes by the main oil gallery in the block.

90mm bore is the maximum size with a 3.65mm wall thickness still retained. Compare that to a 87mm bore in a standard block you only have 2.5mm cylinder thickness at the thinnest area. The version 3 engine will first have an 89mm bore giving me the ability for 2 oversize cuts later.

The new sleeve setup also converts the block to a wet sleeve design, which will massively help with heat management. While my engine cruises on the nismo thermostat at 68 degrees most of the time and oil temps are around 10-11 degrees warmer, when I give the engine a hard time the oil temps do get higher faster than I'd like. I put this down to the partial grout fill in the block, as more cylinder heat is being taken away by oil than by coolant.

I've got a full counterweight nitto 90mm crank with SR20 journals and a set of nitto sr20 ibeams for internals for the V3 engien. With the 89mm bore that makes 3360cc the minimum capacity and a max of 3436cc with a 90mm bore.

Im torn as to weather to use the GTX2860r's or a GTX40-42 on the version 3 engine. I do like the idea of keeping my near stock looking appearance... Be sure I will start a new thread for this when it starts going together.

Cheers,

Ian

sounds awesome Ian!! cant wait to see how the new engine goes. can i have the RB31 when u put the Ver 3 in?? :D;)

EDIT: i just started drooling while thinking about the V3 running a 94mm stroke. holy RB36 batman!! (3589cc for those playing at home)

Edited by Raysboostin
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Im pretty sure a 94mm crank won't fit an RB26 block as the sides of the rods would make contact with the cylinder walls at 90 degrees BTDC and ATDC. From memory the 87mm stroke had the rods about 1.5mm from the base of the cylinder walls. The rod ratio would get very ugly too at 1.45. The Nitto 90mm crank will be closer, but the bore is also 1.5mm larger too to help compensate.

Ray, Its likely the RB315 will be being dismanteled. I need the head, internals and sump for another engine. The 'plan' is to prepare 2-3 blocks with sleeves and spacers this time (not all will become complete engines initially). Sort of a mini production run. When I finish I can then decide if I want to go further or just look into selling the design. I'd like to have one motor to sell and one to keep at the end of the V3 project, and selling a complete engine with the design makes sense.

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wow you do some amazing stuff in here....

I have a question regarding the Carbon clutch... I've just taken out my Carbonetic twin due to the constant slipping when not hot..does the Exedy one require warming up before putting your foot into it?

Its not very practical to have to warm the clutch up just to be able to overtake etc... even in the instructions, Carbonetic recommend slipping the clutch at 3-4k rpm, 3-4 times to warm it up before drive hard?

Edited by tricstar
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No warm up issues with the clutch at all, although I always drive my car to thermostat temp before giving it a hard time. Perhaps thats considered enough warm up. I don't have to leave home and drive at highway speeds either. Its usually grid locked 60km/h in an 80 zone...

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Ray, Its likely the RB315 will be being dismanteled. I need the head, internals and sump for another engine. The 'plan' is to prepare 2-3 blocks with sleeves and spacers this time (not all will become complete engines initially). Sort of a mini production run. When I finish I can then decide if I want to go further or just look into selling the design. I'd like to have one motor to sell and one to keep at the end of the V3 project, and selling a complete engine with the design makes sense.

hey no harm in asking :) hands up for the 1st production run though. :thumbsup:

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  • 11 months later...

Final post for the open deck V2 engine.

The engine is now out of the car and has been disassembled.

The last attempts to get more power out of the engine started producing some worrying results. Specifically the EGTs were climbing through the roof. This had me thinking that I had burnt a valve or something. The motor also suffered from valve float above 6500 RPM, which is the main reason I couldn't break the 400kw goal. 385 was the best I could do.

Initially I had put this down to issues with back pressure as the Greddy extension dumps are only 70mm at the flange to the y pipe, but this combined with valve float meant that revving it was just not making power. Cranking more boost into it made the issue exponentially worse as well. Higher boost caused the power to drop off sooner.

I tried compensating with valve timing and while spool became better, power did not improve. Finally when EGT's began climbing I realised where the issue was.

The final results of the tear down turned out to not be as bad as I expected. Burnt valves on cylinders 1 and 3, no collateral damage at all. In hindsight I should have used a properly developed head, instead of a reco-second hand head. The head had failed its vacuum test initially too, so the valves were probably a little bent before it was stripped and re-assembled. I suspect due to the head having been put on the bench with the cams still in it.

I am especially happy with how the modified crankshaft has held up, as due to the offset grinding of the journals (to increase the stroke to 87mm and reduce the journal size to 48mm) the nitride surface is no more. All up the engine has about 26,000km on it. About 10 of those aren't terribly savage, but the rest of the time I gave the engine a hard time daily with up to 30lb boost. The rod journals still look like they did straight from the machine shop.

So that's all for this engine. I have learnt a lot from the process, and 2 years down the track I have now developed a V3 engine. I'll be posting up the build thread a little later tonight.

Cheers,

Ian Swinkels

post-26553-0-02554800-1383558115_thumb.jpg

Edited by GTRNUR
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  • 2 years later...

Ha ha, you guys beat me to it! The RB34 is a finished project for the most part too.

The two engines being machine at the moment that are based on the RB34 design are certainly going to cause a stir in the GTR world.

Some of those guys you mentioned are familiar, some are members of the Cairns skyline facebook group. We haven't gone on cruise for a very long time though. This will probably been changing with a new JDM group that is forming up here though.

Edited by GTRNUR
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