SD-22 rebuild

[ffdjm]

The SD22 in my Datsun 720 pickup burned so much oil after 252,000 miles that it was replaced. Now I need to rebuild it to original specs. The only source of rebuilding kits seems to be Motor Power Inc. This is not a popular subject on this forum, but does anyone have any experience with complete rebuilds? Blow-by and oil consumption was the only problem with the engine.

Douglas

[asavage]

Welcome to our Sandbox!

Philip wrote a post that shows some variation in piston design. And another post shows some crankshaft & bearing variations, good pictures.

I don't know whether "best shop practice" for the SD is to resleeve or rebore. I've heard of people rebuilding using either method. The FSM shows R&R the sleeves, and the OEM tool to do so. I think the one "rebuild kit" I looked at was sleeves/pistons/rings, and bearings.

There is no timing chain, so I'm guessing that a "rebuild" exclusive of the head and fuel system, involves grinding the crank, new pistons/rings, and either a rebore or resleeve.

[philip]

These sleeves are pretty thin. Nissan does not offer any oversized pistons. If there are aftermarket oversize pistons, the oversized pistons, oversized rings, and machining labor would not be optimal.

Galen Guest

Galen Guest

There is no timing chain, so I'm guessing that a "rebuild" exclusive of the head and fuel system, involves grinding the crank, new pistons/rings, and either a rebore or resleeve. SNIP

Add to the list of likely hard part replacements; a new camshaft, followers, cam bearings, & oil pump.

[philip]

The SD22 in my Datsun 720 pickup burned so much oil after 252,000 miles that it was replaced. Now I need to rebuild it to original specs. The only source of rebuilding kits seems to be Motor Power Inc. This is not a popular subject on this forum, but does anyone have any experience with complete rebuilds? Blow-by and oil consumption was the only problem with the engine.

Douglas

Check with JESCO at:

http://jescoweb.com/nissaneng.htm#DIRECTORY

[asavage]

. . . there are (apparently) no aftermarket oversize pistons.

Bowden Engine Parts (PDF price list) (USD$35) (Aug-05 prices).

While shipping from NZ isn't cheap, even going with the sleeve setup and shipping isn't going to be terribly expensive, at least for pistons etc. The cost of boring vs sleeve presswork might be an issue though, depending upon local resources.

Joseph engine parts lists one 0.50mm (0.020") oversize piston set.
(PDF application list)

Add to the list of likely hard part replacements; a new camshaft, followers, cam bearings, & oil pump.

I knew I was forgetting something

While the oil pump is probably easy enough to find, what about the camshaft? I wonder if it's a regrind-only proposition. And lifters?

[philip]

Points:
1) The five ring piston is not used in road going SD2x engines. The steel piston ring carrier in the 3 ring piston is necessary for road SD engines because they see sustained RPM above maximum torque and at full throttle. Road SD2x engines also had to meet EPA exhaust emissions for some number of hours or miles ... just like gasoline engines. Comparatively, marine, forklifts, stationary applications have an easier life as they are typically limited to maxium torque (1900 rpm) and never had to meet any smog regulations.

2) If any aftermarket mfgr makes a small overbore piston/ring set, I will GLADLY pay the higher price for matched cylinder / piston / ring / wrist pin kit in the original size than go for an overbore as these cylinder liners are pretty thin to start with. Looking at this cylinder, 0.010" overbore MIGHT not fully remove this deep scoring (just my guess).

G.G.

3) Regarding the cam, Galen has provided me with this picture of the cam and cylinders from his engine. NOT pretty. The cam lobe erosion and cylinder scores present are serious. Forever experimenting Galen had his cam reground to a different slightly different specification. SD-22 cam regrind

G.G.

[philip]

(post moved from the SD22 Waterpump thread)

How many miles have you put on your diesel? Sounds like alot, I'd sure be curious to hear who has the most miles on an SD.

(Douglas writes)

252k miles on the original engine. I'm overhauling it now. Excepting the rings the engine is in good condition. No wear on the crankshaft bearings. Camshaft shows some wear, about .005 inch. I'm stalled at the moment because the puller I'm building for the liners requires some welding, the welder is outside, and we are having a very wet autumn. The overhaul kit has 5 ring pistons which hopefully will cure the early onset of oil consumption and blowby.

Douglas

[philip]

252k miles on the original engine. I'm overhauling it now. Excepting the rings the engine is in good condition. No wear on the crankshaft bearings. Camshaft shows some wear, about .005 inch. I'm stalled at the moment because the puller I'm building for the liners requires some welding, the welder is outside, and we are having a very wet autumn. The overhaul kit has 5 ring pistons which hopefully will cure the early onset of oil consumption and blowby.

Douglas

Nowhere in any factory books in my possession are the 5 ring pistons installed in road vehicles. They are reserved for low rpm marine and industrial applications. This is especially true if you have the misfortune to get the 5 ring pistions WITHOUT the cast-in steel compression ring carriers.

SD22 Pistons

[ffdjm]

Nissan publication SSD22Z002 titled "Nissan Diesel SD22 Engine For Automotive and Industrial Use" mentions under Design Features / Pistons and Rings: "Aluminum alloy piston for high strength, lightweight and good heat conductivity; three compression and two oil control rings".

It is to be understood from this brochure that automotive engines are fitted with 5 ring pistons. The brochure was acquired no earlier than 1985 and presumably describes a more recent version of the engine in my 720.

Douglas

[philip]

Nissan publication SSD22Z002 titled "Nissan Diesel SD22 Engine For Automotive and Industrial Use" mentions under Design Features / Pistons and Rings: "Aluminum alloy piston for high strength, lightweight and good heat conductivity; three compression and two oil control rings".

It is to be understood from this brochure that automotive engines are fitted with 5 ring pistons. The brochure was acquired no earlier than 1985 and presumably describes a more recent version of the engine in my 720.

Douglas

The brochure you have provided is a general advertisement for SD22 engines. It is not a factory service manual nor automotive specific and therefore is not beholden to technical accuracy. In fine print, the brochure also had this disclaimer:



No SD four cylinder built after 1980 for road vehicles was fitted with 5 ring pistons.

In November 1980, Nissan released a 33 page "product bulletin" booklet (PB1E-V058U0) to dealership technicians detailing all the specifics of the SD22 as fitted to pickup trucks. The scan in the Pistons thread is from that product bulletin booklet. The most important piston improvement is the steel compresson ring carrier and a reduction in the number of piston rings. More rings create more friction and increased fuel consumption.

Additionally, you will find only three ring pistons with the steel compression ring carrier in the SD23 & SD25 (1984 -on) and all of the TD series four cylinder diesels (turbo and NA) that replaced the SD series.

[ia720]

I have 720 SD-22 with compression bubbling into the coolant. So I have a lot questions on overhauling one.

Are these two Service Bulletins easily available to non-professional mechanics? Are they posted online somewhere, still sold by Nissan, commonly on eBay, or through used manual dealers?

Another big question I have is where can I find more detailed information on the commonalities and differences between the design and parts for Automotive and Industrial SD-22 engines and controls?

A forklift repair company in the area has quoted some much better prices to me for 'some' overhaul parts. But they do not have a 'Part Number' interchange list to guarantee that the parts will do the job. They have told me that the parts are 'not current', special order, and not returnable. So I'd like to be sure of what I'm getting before I buy.

Do any companies like Federal-Mogel produce some detailed lists and cross references?

What are the opinions/facts about using new head bolts when replacing head gaskets?

On the quick-and-easy front does anybody have any experince with block/head gasket sealants like ThermaGasket from RXauto.com? They claim a 94% success rate and actually belong to the Better Business Bureau.

[asavage]

I have 720 SD-22 with compression bubbling into the coolant.

What are the opinions/facts about using new head bolts when replacing head gaskets?

TTBOMK, the SD head bolts are not torque-to-yleld, and in the absence of info otherwise, I'd be reusing them.

On the quick-and-easy front does anybody have any experince with block/head gasket sealants like ThermaGasket from RXauto.com? They claim a 94% success rate and actually belong to the Better Business Bureau.

If you live in a relatively cool area, the majic pihl stuff does work -- at least on gassers. I wouldn't bet on them working on a diesel, but if you

* Really, really don't want to pull the head,
* Don't need full heat transfer capability of the OEM cooling system,
* Don't need high reliability,
* Are willing to take a chance on further spot overheating damage,
* Aren't running the SD22 at a high percentage of its rated HP,

then block goo might do the trick. It's certainly a lot cheaper & easier than replacing the head gasket.

However, as these things go, the SD22's head is pretty darned easy to R&R. And if the head is cracked, I'm sceptical that block goo is going to be a long-term solution.

[philip]

I have 720 SD-22 with compression bubbling into the coolant. So I have a lot questions on overhauling one.

Are these two Service Bulletins easily available to non-professional mechanics? Are they posted online somewhere, still sold by Nissan, commonly on eBay, or through used manual dealers?

Not "easily." Scouring the landscape and dumb luck in my case.

Another big question I have is where can I find more detailed information on the commonalities and differences between the design and parts for Automotive and Industrial SD-22 engines and controls?

More to the point would be for you to possess a Nissan Factory Service Manual for your year truck. Chiltons/Hayes are not detailed enough. See eBay. Pistons, injection calibrations, and injection pump controls are the three majors.

A forklift repair company in the area has quoted some much better prices to me for 'some' overhaul parts. But they do not have a 'Part Number' interchange list to guarantee that the parts will do the job. They have told me that the parts are 'not current', special order, and not returnable. So I'd like to be sure of what I'm getting before I buy.

I've dealt with a Nissan forklift dealer in Santa Fe Springs (east of Los Angeles) a number of times. They are order takers by and large so it's up to you to tell them the right things. For instance, they may have never seen a 3 ring piston or an oil heat exchanger housing with a threaded hole for the EGR coolant temperature switch.

Do any companies like Federal-Mogel produce some detailed lists and cross references? SNIP

The Great 3 vs. 5 Main Bearing Shell Caper proves some cataloging errors are systemic.