Starting My Own Slapper

[SECURITY]

im putting together a slapper to get me around while my motor gets sorted out.

right now ive got some cast Federal and Mogul pistons which i want to use. im pretty sure they are for a standard rb30de. what will the comp ratio be with a rb25det head?

i've also got rb26 pistons, would these be a better way to go?

also is the rb30 oil pump still ok to use?

this will be a work in progress with detailed pics and stuff, should i not bother because there are heaps of these around?

[JonnoHR31]

30de pistons? you mean 30e?

[GTScotT]

its interesting, id love someone to clarify the static CR of a 30e with a 25 head.

i was under the impression it will be lower than the standard CR of the 30e, and that confuses me when looking to buy pistons to suit the 30e bottom end... if their 9:1, will the static CR still be 9:1 with the 25 head? and what of DE to DET heads..

all very interesting

[SECURITY]

rb30e.. whatever.

just need to know what compression the standard pistons would make with the 25det head.

[TiTAN]

as the rb30 guide says. 7:1 with 30ET pistons 8.3:1 with 30E pistons.

the DE/T heads have much larger combustion chambers hence the lower CR, buy pistons made to suit the DET conversion (there is quite a few out there)

[SECURITY]

i might just go with the 30e cast pistons ive got here, 8.3:1 isnt too bad considering i want a reliable quick, cheap build.

Edited February 5, 2010 by SECURITY

[MBS206]

i might just go with the 30e cast pistons ive got here, 8.3:1 isnt too bad considering i want a reliable quick, cheap build.

No such thing as a reliable, quick, cheap build.

Pick two out of the 3.

Also, there are pistons available for 9.0:1 CR with a DET head on them.

Lastly, the oil pumps that are stock I've found are fine to use, so long as you don't limiter bash like I do.

[SECURITY]

No such thing as a reliable, quick, cheap build.

Pick two out of the 3.

Also, there are pistons available for 9.0:1 CR with a DET head on them.

Lastly, the oil pumps that are stock I've found are fine to use, so long as you don't limiter bash like I do.

i think i may prove you wrong on that lol.

ill log all of my expenses

so the rb30 standard pumps are ok? or should i go for a twin cam pump setup? i havent decided if im going to use all of the items off my current rb30 (n1 pump, head etc)

what should i machine off the block if i wanted to make the standard rb30e pistons make the 9.0:1 CR?

[MBS206]

i think i may prove you wrong on that lol.

ill log all of my expenses

so the rb30 standard pumps are ok? or should i go for a twin cam pump setup? i havent decided if im going to use all of the items off my current rb30 (n1 pump, head etc)

what should i machine off the block if i wanted to make the standard rb30e pistons make the 9.0:1 CR?

Try prove me wrong.

Drive it how I drive mine.

It won't last.

RB30 pump is fine for a slapper.

If you're taking your current motor to court etc, don't touch it. Use new shit.

Also, head + new valve stems etc, crack pressure tested, you're looking around $800 - $1000.

I built my last actual engine for $660, that include a new clutch + pressure plate, clutch bolts, head gasket, block etc.

Mine lasted 2 track days and a motorkhana. Now at the Khana it spent 90% of its time at the limiter.

The track days and road life it saw, it spent probably 70% of its time above 4000RPM.

Slapper + abuse = broken, but that's the fun of it.

I haven't broken one yet driving it on the street. But put it on the track and drive it hard... Different matter...

Edit: My next one is getting an RB25 pump in it though.

Edit2: Although, judging how I push a motor, even some built motors wouldnt't last... LOL

[SECURITY]

i barely drive my car, my last motor blew and it barely saw 5000rpm lol.

I've made a list for parts and things i need to do to the block/head. can someone make sure ive covered the "things to do" list, ill figure out the missing parts as i go lol.

Parts:

Federal and mogul cast pistons

VRS kit

Rings

Big end/main bearings

Crank collar

Oil restrictor to head + block read oil gallery

Oil pump rb25/26/n1

Timing belt

Idler + tensioner

Water pump

To do before assembly:

Weld VCT oil feed in head (or grub screw)

Fit 1.5mm oil restrictor + block rear

Drill and tap new idler stud + replace studs

Grind down protruding water galley lumps for exhaust manifold.

Fit crank collar for twin cam oil pump

Questions

Has anyone actually o-ringed their block? Is it worth doing on a slap?

I found this if anyone was interested, DIY o-ring set: http://www.summitracing.com/parts/ISK-200-...mp;autoview=sku

Do I need to do anything to the water galley on the block seeing as though it spans over the oil feed of the head?

I’ve read people using 2x1.5mm restrictors instead of blocking off the rear and using a 1.5mm restrictor in the front. Which is the most commonly used for the rb25det head?

Am I missing anything? I’m pretty keen to get my motor on the stand and started this weekend.

Edited February 5, 2010 by SECURITY

[Adriano]

I wouldnt worry about the crank collar and oil pump, just leave whats there. Are you still running the highflow, if so there will be no need to hit the limiter. Set t he limiter high, as i believe an overrev to say 7200 is better for the motor than hitting a hard limiter at 6500

[emtea]

From what i've read on here about the oil pumps, the standard RB30 oil pump is actually stronger than the RB26/N1 pumps... has a different design on the gears (sawtooth vs georotor or something?).. anyways refer to this post: http://www.skylinesaustralia.com/forums/N1...30#entry4822519

[TiTAN]

Fit 1.5mm oil restrictor + block rear

Don't do that to an RB25 head. i have 2x 1.5mm restrictors in my engine and when it is idling at around 2kg of pressure on the factory gauge you can hear the lifters getting a little noisy.

Has anyone actually o-ringed their block? Is it worth doing on a slap?

Do I need to do anything to the water galley on the block seeing as though it spans over the oil feed of the head?

Block the feed hole into the head and run an RB26 or RB30 head gasket a standard RB26 gasket or a MLS gasket will be fine.

[Ziller]

I'm with MBS206, there's a lot more science to these engines than you might think, you could take your last engine to guys like CRD or similar for a full measure up and engine report with photos if you want some chance of getting your hard earned money back! and then let them to build it, IMO for me!!! ... start with a brand new crankshaft with Nismo bearings, the ground ones limit bearing grades for accurate bearing clearances.

You could buy a shiter just for a run around until you get your other business sorted out as it could take a while, it could save you dollars in the end, anyway best of luck with the path that you choose I hope it all goes well.

[N1GTR]

Haha no one gets new rb30 cranks from Nissan for slappers once they see the price

[MBS206]

i barely drive my car, my last motor blew and it barely saw 5000rpm lol.

I've made a list for parts and things i need to do to the block/head. can someone make sure ive covered the "things to do" list, ill figure out the missing parts as i go lol.

Parts:

Federal and mogul cast pistons

VRS kit

Rings

Big end/main bearings

Crank collar

Oil restrictor to head + block read oil gallery

Oil pump rb25/26/n1

Timing belt

Idler + tensioner

Water pump

To do before assembly:

Weld VCT oil feed in head (or grub screw)

Fit 1.5mm oil restrictor + block rear

Drill and tap new idler stud + replace studs

Grind down protruding water galley lumps for exhaust manifold.

Fit crank collar for twin cam oil pump

Questions

Has anyone actually o-ringed their block? Is it worth doing on a slap?

I found this if anyone was interested, DIY o-ring set: http://www.summitracing.com/parts/ISK-200-...mp;autoview=sku

Do I need to do anything to the water galley on the block seeing as though it spans over the oil feed of the head?

I’ve read people using 2x1.5mm restrictors instead of blocking off the rear and using a 1.5mm restrictor in the front. Which is the most commonly used for the rb25det head?

Am I missing anything? I’m pretty keen to get my motor on the stand and started this weekend.

Please, change the name of the thread... This is not a slapper.

A slapper is a matter of grabbing a running RB30E, pulling the head off, slap an RB26 or RB25 head on (once you do things like block the oil hole in the 25 head).

Do the tensioners, run the external oil feed for VVT, do the external front drain off the factory spot on the 25 head.

Put motor in car, start it, warm it up, rip a skid, check for leaks. (Yes, in that order)

[SECURITY]

I wouldnt worry about the crank collar and oil pump, just leave whats there. Are you still running the highflow, if so there will be no need to hit the limiter. Set t he limiter high, as i believe an overrev to say 7200 is better for the motor than hitting a hard limiter at 6500

From what i've read on here about the oil pumps, the standard RB30 oil pump is actually stronger than the RB26/N1 pumps... has a different design on the gears (sawtooth vs georotor or something?).. anyways refer to this post: http://www.skylinesaustralia.com/forums/N1...30#entry4822519

okay so standard rb30 oil pump will do as long as ive limited it to 7000rpm (not bouncing off the limiter ofcorse)

Don't do that to an RB25 head. i have 2x 1.5mm restrictors in my engine and when it is idling at around 2kg of pressure on the factory gauge you can hear the lifters getting a little noisy.

Block the feed hole into the head and run an RB26 or RB30 head gasket a standard RB26 gasket or a MLS gasket will be fine.

so 2x 1.5mm restrictors on both front and rear oil feeds on the block good enough? does everyone do this?

i dont really like the idea of water hitting the head gasket front on - sounds like possible trouble that can be avoided. i might just have a mate weld a bit of meat to the water galley then match the head gasket with a die grinder then have it machined flat.

everyone agree?

Edited February 6, 2010 by SECURITY

[SECURITY]

Please, change the name of the thread... This is not a slapper.

A slapper is a matter of grabbing a running RB30E, pulling the head off, slap an RB26 or RB25 head on (once you do things like block the oil hole in the 25 head).

Do the tensioners, run the external oil feed for VVT, do the external front drain off the factory spot on the 25 head.

Put motor in car, start it, warm it up, rip a skid, check for leaks. (Yes, in that order)

to me a slapper is doing the basics to get it running reliably then off you go.

[TiTAN]

The RB26 and RB30 gaskets dont have the provisioning for the oil feed up front so the water gallery hole should match the block.

With the oil restrictors some people make them a little larger (from memory status suggested larger than 1.5mm) but i wouldn't be going any smaller.

Edited February 6, 2010 by TiTAN

[MBS206]

to me a slapper is doing the basics to get it running reliably then off you go.

A slapper, is slapped together, with the mind set of "She'll be right"

You're doing a rebuild.