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Discussion Starter #1
Are Sentra pistons stamped on top if over sized? Is the piston in the photo standard? Where can I buy a lower compression piston to fit my 2.5 Spec V engine?
Piston.jpg
 

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I don’t believe it is indicative of the actual sizing. Nissan uses a grade system depending on the crank, piston and rods to match bearings. That is if you’re rebuilding using oem equipment.

Download the fsm and look up how to choose bearings under em.pdf.

Anyway...why the low compression? You may be able to use the base se-r piston and bring it down to a 9.6. Mind you no one has tried it. They also do not use the same block, at least the part numbers are different.
 

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Discussion Starter #3
I don’t believe it is indicative of the actual sizing. Nissan uses a grade system depending on the crank, piston and rods to match bearings. That is if you’re rebuilding using oem equipment.

Download the fsm and look up how to choose bearings under em.pdf.

Anyway...why the low compression? You may be able to use the base se-r piston and bring it down to a 9.6. Mind you no one has tried it. They also do not use the same block, at least the part numbers are different.
Wow, this is a little more than my old brain can handle. I am an old 1960s mechanic trying to rebuild a 2008 engine. I had no idea there were specific bearings I would have to use to rebuild. I thought I could get the crank turned and just buy the over size bearings. I do plan to use the same block, same rods, except for one, same head and maybe new pistons. The reason I want lower compression is so I can use regular gas instead of the high priced gas.

Will I have to have a matched set of rods or can I just buy another rod to replace the bad one? I would have never bought this car had I known it had an engine for hot rods instead of an everyday driver. My wife and I really like the little car we just don't need all the power. If I could find a JDM 2.0 or plain 2.5 that would fit, I would go that route. As far as I know, the SE-R Spec V 2.5 is the only engine that will fit this car.

One more: Where can I buy new bolts for the balance shaft, I had to grind the old ones off as at that time I couldn't find a socket that would fit the bolts, I have one now. Oh and where can I buy the flywheel bolts, I messed one of them up. I have way too many questions and the only reason I ask them here is I can't find them on the internet. I do have the factory manual downloaded, it just doesn't give bolt sizes that I have found.

One more question and I will shut up. Can I pull the 6 speed transmission with the engine in the car? I have a few more questions but I have over stayed my welcome already. I really really do appreciate the help.
 

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Discussion Starter #4
I will start another post to ask more questions, if I am asking too many questions please do let me know. I certainly don't want to be a pest. If I add the detergent (lucas injector cleaner) to each tank of gas, can I use the mid grade or regular gas.

Can the water pump be changed without pulling the engine? Thank you so much for being so patient.

Jim
 

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Honestly, we've found it better to get internal hardware from the dealer parts area.

You won't need a matched set of rods.

As have never pulled anything out of the engineon that frame but I think you have to drop the engine and tranny at the same time due to the sub frame design unless there is a way to do it after the sub frame is dropped and the powertrain is just "floating".
 

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Discussion Starter #6
Thanks Cricki, I appreciate and respect your advice. The clutch plate has a lot of life left and the pressure plate isn't heat checked or anything. I was in hopes I could just pull the transmission without pulling the engine if I had too. It looks like there would be enough room to slide the trans back but I could very well be wrong.

Do you have any idea why there is no pilot shaft bushing or bearing in the pilot shaft bearing spot? There is nothing in there at all, the splines of the pilot shaft go into a hollow place in the end of the crank and just float. That doesn't look to well designed unless he pilot shaft is supported inside the trans.

Thanks again Cricki.
 

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There is no pilot bushing/bearing, I've never had an issue with it and I understand your concerns. One of the cars I had had a pilot bushing/bearing.

If you have the MT section of the FSM, it'll show you if the tranny can be pulled while in the chassis, would just need a way to support it with the subframe and what ever mounts removed.
 

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Discussion Starter #9
Any suggestion where I can buy one piston rod for the little car? They have rods on rockauto but I don't know if the SE-R Spec V 2.5 take a specific rod or not.
 

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I agree, going to the dealer would probably be your best bet for 1 rod. www.nissanpartsdeal.com is an online retailer, but I think they're linked to an actual dealer.

As far as the pilot bushing/bearing yes most of the newer fwd cars don't have them because they don't have long main shafts as opposed to rwd cars.
 
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