B0oStEr

I need an engine machine shop for boring and balancing work, maybe a head service. I'll assemble the motor myself. Any suggestions of someone that will do a good job and offer value for money will be appreciated. Thanks

I was shown a forged piston the other from an rb25 that had seized the exhaust cam. It had two valve sized holes punched clean through it. You should be able to salvage some parts such as block, crank and rods but there is next to no chance the bottom end won't need a full rebuild with new pistons, bearings and a crank grind. Your cheapest way out would be a second hand motor.

Are ACL race gaskets the same as Cometic? They don't list a headgasket for r32 rb25de but they have one for the rb26. I know the rb25det one is different because it has the vct oil feed. Will the rb26 one fit or is there something better for the money? rb25det -------------------------------- rb26

Rb26 and RB25 have the same deck height so no problem. The gudgeon pin is higher in the rb26 piston to accommodate the longer stroke. Most forged RB26 pistons seem to aim for about 8.5:1 CR the same as stock. To get 9:1 CR you will need to deck the block to run minimal piston to head clearance (0.75mm) with a thin gasket or get 9:1 pistons made. The stock RB26 is 2568cc and an 87mm bore gives 2628cc 86.5 mm gives 2598ccRB26

I have an early rb26 crank at the machine shop for the oil pump drive mod. They are machining down the snout to shink fit a billet sleeve which they will machine down to factory spec of the later crank. I've been assured by these guys that setscrews will not be necessary if the collar is done this way.

I went to two local engine builders and both tried to sell me 'mahle' pistons. The second guy pulled one out of a box and I said that looks very similar to an ACL piston. He said it is but it's made by mahle. I've heard the companies are related but do mahle make the forged pistons for ACL? It's obviously not the same as the Mahle pistons you used.

Checking up seems to indicate rb25de and rb26 heads both have chamber volume around 63cc. Where does that leave Wisecos CR specs when they list volume as 70cc?

I just did some checking in the rb30/25 thread. SK states rb26 and rb25de heads have the same size combustion chambers. They each vary according to casting differences somewhere between 62cc and 64cc.

Yes 2568cc as both engines have an 86mm bore. Sorry which head has the smaller dome/chamber? As far as I know they have the same volume but I've only been told. I'll have to check it out for myself. On my "to do" list. I'm hoping to get a CR of 8.5:1 Anyone care to comment on chamber volume r32 rb25de head vs rb26? NutR33 How did you hold the crank still to get it that tight?

Remove the piping.

I need pistons for an rb25 buildup using rb26 crank and rods. I've been looking at some used rb26 wiseco forgies but have found out that wiseco spec their compression ratio at 7.9:1 or 8.25:1 if you deck the max off the block. I was hoping to keep comp. at 8.5 for off boost response. Dome volume is listed as 14cc compared to ACL of 16cc for 8.5 CR Wiseco list the rb26 chamber volume as 70cc and I thought it was less than this. Can anyone who has used wiseco pistons in their rb26 please comment on CR?

OK it's not essential but it's good for your peace of mind.

I rechecked the acl site and they list the rb25de/det thrust bearing at pos 7 not at 6 as I thought but as you say it's in pos. 4 so I've got nothing to worry about. The cranks off getting an oil pump collar fitted so I'll have to check the balancer bolt thread when it comes back. Is there anything special about the bolt eg. a step or nonstandard thread or could I just get a high tensile bolt from a bolt shop? The balancer that was on the rb25 only has a three rib PS pulley and I need a four rib pulley for my r32 hicas so I hope the rb20 balancer fits.

It needs a collar if it's going into an R32 also.

I guess I'd better carefully check the lifters for my rebuild. Are there any nonmetal parts that can harden or degrade? I suppose they can't be pulled apart. Does anybody have a diagram showing the internals of the nissan lifters?

Manual or auto?

There were some RDA slotteds on ebay $270 buy it now I think. EDIT:Some there now $225 pair buy it now

Actually in the r32 the sedan exhaust fits the same as the coupe. I believe the R33 sedan exhaust is a bit longer than the coupe.

Good results I've been looking for someone to tune my pfc. Where does Matt work?

If it doesn't have a green label you will need to rechip your ecu. They are often fixable. Search afm resolder or similar.

Hey I know some of you guys have done this. I'm just trying to get the right bits together before I pull my motor down.

Jaycar kits aside, Innovate are good value for money if you compare it to other wideband A/F ratio meters IMO Innovate also make a small dash mountable gauge for simlar $$$ that does the same thing.

If your running too much boost, running a lean air fuel ratio, too much ignition timing, less than 98ron fuel or any combination of these will cause detonation (aka pinging, aka can of marbles) will destroy your engine. I'm surprised it hasn't already as from your description of the sound I'd say the condition is quite severe.

So they don't fit R32 Gtst with type m brakes? Not 4 spot calipers?