Rod Knock- Rebuild or buy new engine?

[fourgsixthree33]

I recently got rod knock not too long ago. Thought at first I bent valves from the timing jumping but it turned out that the bottom end needs work. So, here I am with a new rebuilt/reman head with a 3 angle valve job, new parts, the whole deal. Bought the head before knowing I had problems in the bottom end. Should have dropped the pan from the beginning.

So, I am planning on getting a short block locally for $150. Needs new bearings due to the previous owner taking out the rod caps. It's a complete short block from a 97 DSM. I am stuck with my 7 bolt head so I need a 7 bolt block. If I didn't have this head, I would find a 6 bolt long block. But that's not logical since I already purchased this head.

The other thing I could do is pull this engine and rebuild it. But with down time, money in the long run, etc. I think it would be better just to get a short block. Then over the course of the next year, build this one up.

What would you guys do?

 

[fourgsixthree33]

Yea seems like a lot of us are having issues recently. Kind of sad. But we keep chuggin!

 

[g4ebguy90]

Man, spun bearing 5th day of ownership. Swapped blocks, now it has no power with the MAF plugged in, and I've done everything. I just leave it unhooked, and she pulls good enough for me to live with.

 

[ed1380]

A couple weeks ago, I bought Evo 8 rods and pistons for $100 shipped to my front door. So, I have decided to rebuild. Bearings are cheap. $32 for the main bearings and $20 for the rod bearings on Extreme PSI.

The rings on the pistons I got look great. They only have 58K on them when the engine was pulled. So I am going to skip out on getting new rings. The seller (very nice guy and trustworthy) said he would use the current rings as well.

I am going to get my crank looked at and see what they say. I doubt there is anything wrong with it but I will explore my options.

So if I already spent $100 on these evo 8 pistons and rods and spend roughly $65 tops for these bearings and for shipping costs, get the crank looked at, I don't think I will be spending anything over $500. Depending on the crank situation, I may not even see over $300. I am honing the cylinder walls myself.

Granite I already bought a brand new head, all gaskets, all timing belt components, and a crap load of other stuff. So that helps out a bit.

Here are some pics of the Evo 8 pistons and rods. I also have a project log here- Eat Sleep DSM - 1G: Frequent Flyer- 93 Eagle Talon TSi AWD

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Since it's $35 for rings, might as well

 

[fourgsixthree33]

Where do you find Evo 8 rings for $35?

 

[ed1380]

I found a set of wiseco rings for the 7 bolt on eBay for that price. If the pistons fit the same bore, I'm guessing they shouldn't be that much more

 

[fourgsixthree33]

STM sells them for $25/per cylinder. That is about the cheapest I have found so far. The graveyard's price is $52/per cylinder. =0

 

[ed1380]

My bad. Thought it was for a whole set. It does interchange with the dsm. Maybe the dsm ones are cheaper
http://cgi.ebay.com/Wiseco-Piston-Rings-kit-85mm-DSM-Evo-Eclipse-4g63-mitsu-/350472927568

More ebaying shows npr rings for the dsm's at $35 for a whole set made in Japan. (Npr is an oem supplier)

 

[fourgsixthree33]

Think I could trust the add in the link you provided? I don't buy on ebay.

 

[ed1380]

I buy and sell on eBay alot. If anything makes you not happy, eBay/PayPal always side with the buyer. Unless you broke the rings, you'll get your money back. I don't get why sellers sometimes put "no returns"

 

[fourgsixthree33]

I will do some looking around and see what I can find.

 

[fourgsixthree33]

Can anyone tell me which way the Evo 8 pistons face? Dots towards the timing belt or towards the tranny? There was a guy on here who put them in with the dots facing the timing belt side. But wouldn't that be wrong due to the valve reliefs?

Though the Evo 8 has the timing belt on the passenger side of the car, the exhaust valves are still on the radiator side of the engine while the intake is on the firewall side. So you would put them in just like the DSM pistons. So if I put them in with the dots facing the timing belt, it would make the exhaust valve reliefs go to were the intake is.

Right?

 

[bryanwheat]

The alignment dot still goes towards the timing belt. The valve reliefs will be on the opposite side, but it isn't a huge deal if you don't have bigger valves or big cams. You want to keep the pin offset correct to the rotation of the crank. By the way, the 1g and 2g piston rings will not fit an evo piston. Yes the bore is the same diameter but the ring slot in the piston is a different diameter and requires a different size ring. Evo rings are 1.2 x 1.2 x 2.0mm, 7 bolt rings are 1.2 x 1.5 x 2.8mm, and 6 bolt rings are 1.2 x 1.5 x 3.0mm . Also there are plenty good engine parts on ebay. Mizzumo is one of the good ones. They carry complete re-ring kits which includes nps rings, which happen to be one of the highest quality rings you can get, acl accuglide bearings, and a full quality gasket set. All for around 120 dollars. They also sell packages with the npr pistons, npr rings, and acl bearings for 130 dollars.

 

[Sean99RS]

I'm loving all these write-ups. If any haven't seen, i have a 99 RS 420a with rod knock due to wrist pin failure, so im babying it for now, but as soon as i have a daily beater im going to tear the motor down and rebuild. Glad to see all the write-ups and work ya'll are doing to your dsm's.

 

[bryanwheat]

I'm loving all these write-ups. If any haven't seen, i have a 99 RS 420a with rod knock due to wrist pin failure, so im babying it for now, but as soon as i have a daily beater im going to tear the motor down and rebuild. Glad to see all the write-ups and work ya'll are doing to your dsm's.

If you truly have a rod bearing clearance issue or a spun bearing than it won't last long.

 

[ed1380]

He said his rod knock is due to piston pin not bearings.

 

[JusMX141]

If any haven't seen, i have a 99 RS 420a with rod knock due to wrist pin failure

How are you certain that it's a wrist pin issue? Have you dropped the pan and checked the rod bearings?

Often if rod knock is caught in a very early stage you can install a new set of bearings before it ruins the crank. Once the crank is scored, so is your wallet.

 

[Sean99RS]

I had a friend of mine who works at a dealership service center check it out. They said wrist pin, however, im not sure if they dropped the pan, he didn't charge me for anything. With that said, i'm dropping the pan next weekend. The knock hasn't gotten worse or louder but im not taking any chances. I'm looking around for a 500-1500 car to use as my daily beater until i can get the motor torn down and rebuilt.

Well let me ask this of the guys who've been working on these ladies longer than i have. Without dropping the pan, how accurate could they really be on wrist pin? I don't believe the pan was dropped, so i believe the mechanic my friend had check it just listened to it with a stetho.

 

[fourgsixthree33]

The alignment dot still goes towards the timing belt. The valve reliefs will be on the opposite side, but it isn't a huge deal if you don't have bigger valves or big cams. You want to keep the pin offset correct to the rotation of the crank. By the way, the 1g and 2g piston rings will not fit an evo piston. Yes the bore is the same diameter but the ring slot in the piston is a different diameter and requires a different size ring. Evo rings are 1.2 x 1.2 x 2.0mm, 7 bolt rings are 1.2 x 1.5 x 2.8mm, and 6 bolt rings are 1.2 x 1.5 x 3.0mm . Also there are plenty good engine parts on ebay. Mizzumo is one of the good ones. They carry complete re-ring kits which includes nps rings, which happen to be one of the highest quality rings you can get, acl accuglide bearings, and a full quality gasket set. All for around 120 dollars. They also sell packages with the npr pistons, npr rings, and acl bearings for 130 dollars.

Fu*king amazing info! This has been confusing. Some saying to flip the pistons, others saying not to. I have always thought the piston offset to the crank was the more important concern. Since the evo 8 pistons sit lower in our blocks, the valve reliefs shouldn't be an issue. So I will install them with the alignment dot facing towards the timing belt side.

I did know the piston rings between the two pistons are different. Just as you stated. I did get some rings for the evo 8 piston.

Again, thanks for the info as it will really help me out. My short block should be here Monday or Tuesday. In which I am then going to strip it, clean it, install my evo 8's and rod bearings, then start bolting stuff back up.

 

[DSMReviver]

Not only should the valve relieve be a concern, the piston wrist pin hole is off set in evo pistons(1mm offset). this give it better rod angle ratio in evo motors.

If you install it in a dsm engine and get it wrong, your rod angle ratio will be worst off.