2G Suggestions on what oil to use based on Piston To Wall Clearance?

[GIB]

98 GSX 2.4 Stroker
Wiseco 1800HD pistons (87mm)
.0045 Piston to wall clearance
8.5:1 Ratio

Let's talk oil.
I'm about 500 miles away from the end of my break in period.
I'm using Penn Grade 30W break in Oil.
I planned to use 5w-30 or 0w-30 synthetic.
There have been some great news oil types created since this car came out...
?Are there any better suggestions on what oil is best?
What are you using?

 

[diambo4life]

Your bearing oil clearances should determine your oil weight choice not the PTW clearance imo. I am a lover of 20W-50 weights on DSMs especially in the summer months and run nothing lighter than 10W-30 in the winter months. I just stick to what I have been doing for over 25years. In my Mustang that comes with much tighter clearances, it's usually on 5W-40 to 15W-50.

 

[GIB]

Your bearing oil clearances should determine your oil weight choice not the PTW clearance imo. I am a lover of 20W-50 weights on DSMs especially in the summer months and run nothing lighter than 10W-30 in the winter months. I just stick to what I have been doing for over 25years. In my Mustang that comes with much tighter clearances, it's usually on 5W-40 to 15W-50.

Thanks.
I'd have to check with the machine shop on the bearing clearance. They only other gave is the ring gaps 1st ring .017, second .019.
If I can get those bearing clearances I will post them.
? Would synthetic vs conventional matter with those suggested oil weights?

 

[diambo4life]

Oil science has very differing opinions. I am of the school of thought of clean fresh oil and changing it regularly. In our DSMs, I run almost exclusively the conventional Valvoline VR1 stuff but I also had plenty of good experiences with conventional Castrol GTX just because it was easy to obtain. If you can get synthetic at good prices, power to you. Is it necessary? No. Do note some of those lower viscosities are only in synthetic formulations. Those ring gaps work well in my experience.

I have been hearing good things about the Driven oil brand as well. But my DSM will be running off the shelf stuff most likely when it's ready to go on the road.

 

[jdxnc]

Also take into account what your use application is, a car that will be daily driven is different than one that only does 1/4 mile runs where you don't care about efficiency but need maximum protection.

 

[1990TSIAWDTALON]

I, personally, would run another round of regular oil of your choice, on the next oil change, just to make sure the rings seated well and THEN decide if you want to run synthetic. If you throw synthetic in there before the rings are seated well, you will have some blow by, as synthetic stops the seating process. I put 1000-1500 on my engines before I give it the ok to go synthetic. Just my 2 cents. Any leaks will also become worse, so make sure your motor is ready.

 

[curt-s]

Indeed.
Anecdote: I'm at 500km, already switched from BI to regular oil, and I don't think I'll ever go synthetic. Sticking with Driven HR5 10W40 until it's no longer available for one reason or another. My PTW is a bit tighter, my ring gaps a tad looser, and my bearing clearances at the loose side of OE spec.

I'm wondering about the choice of those tighter ring gaps. What led you to that and not a bit looser to support the higher power?

 

[GIB]

I'm wondering about the choice of those tighter ring gaps. What led you to that and not a bit looser to support the higher power?

I read it on a post here:

https://www.dsmtuners.com/threads/piston-ring-gap.491423/

I'm only at 400 Whp. I really don't plan to go higher.

 

[curt-s]

That's what I was wondering, .017 and .019 may be a tad tight just because of the tuning factor. You'll have to manage your cylinder pressure and heat closely. 400whp is a lot, even for a 2.4. your BHP will be nearer 500.
Those on that link suggest looser. Wiseco does recommend .005-.0055 per inch of bore for your application but adding a bit of padding is preferential to being on the line, mainly due to the tuning process likely creating unstable conditions.

But whats done is done, so just keep your timing conservative and boost lower.
Every so often throw a bore scope down there and check for scoring on the cylinder walls indicative of butted ring ends or breaks. It'll be pretty obvious.

There's little reason to go synthetic unless you want/need the fancy weights. Your bearing clearances and power level will dictate your weight as anything will lube the walls good enough for modern piston skirts. As mentioned, just stay away from synth for a while still.

...and the super cheap Walmart oils.

 

[GIB]

That's what I was wondering, .017 and .019 may be a tad tight just because of the tuning factor. You'll have to manage your cylinder pressure and heat closely.
Those on that link suggest looser. Wiseco does recommend .005-.0055 for your application but adding a bit of padding is preferential to being on the line, mainly due to the tuning process likely creating unstable conditions.

But whats done is done, so just keep your timing conservative and boost lower.
Every so often throw a bore scope down there and check for scoring on the cylinder walls indicative of butted ring ends or breaks. It'll be pretty obvious.

There's little reason to go synthetic unless you want/need the fancy weights. Your bearing clearances and power level will dictate your weight as anything will lube the walls good enough for modern piston skirts. As mentioned, just stay away from synth for a while still.

...and the super cheap Walmart oils.

Thank you. I don't remember our whole conversation with the machine shop, but I did say I want it looser than stock. I guess they didn't do that. I will make sure to use a good oil.
I appreciate this help so much, because I was on the route to use a bad product.
So...
? would you say it is safe to go with a conventional 20W-40 or if not available a conventional 10W-30?

 

[diambo4life]

I have always run tighter on Wiseco. Heck they used to recommend tighter than that back in the day. I find it's a good compromise for power and not getting excessive blowby. I will second on not running synthetic oil during the break in period which for me is usually 100 miles if that .

 

[curt-s]

Thank you. I don't remember our whole conversation with the machine shop, but I did say I want it looser than stock. I guess they didn't do that. I will make sure to use a good oil.
I appreciate this help so much, because I was on the route to use a bad product.
So...
? would you say it is safe to go with a conventional 20W-40 or if not available a conventional 10W-30?

When they tell you your bearing clearances, you'll be able to pick your oil more accurately.

For them to adjust bearing clearances, they'd have to size the big ends of your rods. Did they do that or are they run straight up?
Guess it doesn't really matter as they should be giving you your numbers on request.

20w50 isn't a magic oil that can be used in all cases. You may be better off with a 10w40 or 30, depending on those clearances.
Then there's also 15w40..what fun.

I assume to get the 2.4 you used 87mm with a 100mm crank?
That's going to be a fair bit of low end torque, so bearing clearance and quality oil selection will be even more crucial. I'd be sporting a high quality for that personally

 

[GIB]

When they tell you your bearing clearances, you'll be able to pick your oil more accurately.

For them to adjust bearing clearances, they'd have to size the big ends of your rods. Did they do that or are they run straight up?
Guess it doesn't really matter as they should be giving you your numbers on request.

20w50 isn't a magic oil that can be used in all cases. You may be better off with a 10w40 or 30, depending on those clearances.
Then there's also 15w40..what fun.

I assume to get the 2.4 you used 87mm with a 100mm crank?
That's going to be a fair bit of low end torque, so bearing clearance and quality oil selection will be even more crucial. I'd be sporting a high quality for that personally

I hope to get an answer on my bearing clearances this week. I had King XL standard size bearings put on the rods and mains.
Yes, I have 100mm Manley crank. 87mm Wiseco 1800HD Pistons. 156mm Manley H-Tuff Rods with a 21mm wrist pin.
I am hitting boost at about 4300 RPM. About 394 Torque.
It is great on the street. I'm very happy with how it drives. May be my favorite Stroker so far for the street. It is very peppy, very fast acceleration.

 

[curt-s]

I have a set of King bearings in a box still. Measured out, they ended up being a tad tighter than the ACLs, about 2/10ths of a thousand on average. That's likely due to their proprietary coating.

Lots of torque low down is great for peppiness, but harder on bearings and the oil wedge. Rod angle also plays an important role. That's why it's even more important to select clearances and an oil weight and quality that mate well to the power band and internal geometry. Once you know the numbers, you can select a high quality appropriate weight and put it out of your mind

 

[GIB]

I hope to get an answer on my bearing clearances this week. I had King XL standard size bearings put on the rods and mains.
Yes, I have 100mm Manley crank. 87mm Wiseco 1800HD Pistons. 156mm Manley H-Tuff Rods with a 21mm wrist pin.
I am hitting boost at about 4300 RPM. About 394 Torque.
It is great on the street. I'm very happy with how it drives. May be my favorite Stroker so far for the street. It is very peppy, very fast acceleration.

Correction Edit: I have 150mm rods.

 

[GIB]

The machine shop didn't have details on the bearing clearances. I will make sure that next time I have this type of work done, that they give me the info.
Main bearings are Standard size King XL brand.
Rod Bearings are Standard size King XL brand.
I don't plan to race the car ever. It is made for the street.
10W-30 conventional for summer
5W-30 conventional for winter
Sound safe?

I really appreciate the help from you all!

 

[curt-s]

How the hell did they manage to do a motor without checking clearances? You shouldn't even need to ask for them to record that. They would need that to verify they didn't f something up.

Of course, I ask that when my own selection of shop for work managed to overbore mine way too large necessitating I replace them.
But even then, they still managed to give me the numbers even though they were way larger than I asked.

before: "yeah we can do that"
After I told them they did it wrong: "we're not a performance shop"

Anyhoo, without knowing your clearances, I would suggest against running a heavy weight oil. At this point, dropping the pan to check yourself will only give you plastigauge accuracy.

But you can run a 10w40 on a stock clearance motor in the summer. Perhaps ask Manley what they spec their rods at. As I mentioned, Kings super hard coating is a tad thicker than a normal bearing.

You don't need to race your motor. Actually, with a 2.4, city driving could be harder on it over time because you spend more of it in peak torque. Race 4gs are generally 2.0L.

 

[GIB]

How the hell did they manage to do a motor without checking clearances? You shouldn't even need to ask for them to record that. They would need that to verify they didn't f something up.

Of course, I ask that when my own selection of shop for work managed to overbore mine way too large necessitating I replace them.
But even then, they still managed to give me the numbers even though they were way larger than I asked.

before: "yeah we can do that"
After I told them they did it wrong: "we're not a performance shop"

Anyhoo, without knowing your clearances, I would suggest against running a heavy weight oil. At this point, dropping the pan to check yourself will only give you plastigauge accuracy.

But you can run a 10w40 on a stock clearance motor in the summer. Perhaps ask Manley what they spec their rods at. As I mentioned, Kings super hard coating is a tad thicker than a normal bearing.

You don't need to race your motor. Actually, with a 2.4, city driving could be harder on it over time because you spend more of it in peak torque. Race 4gs are generally 2.0L.

Yep. They just don't keep records after building.
They said that they gave me a spec sheet, that I cannot find. Hmm... I will search for that.
Well, I will make sure to have the engine inspected to see if there are any issues.
I will also see what Manley has to say.
I've driven about 1030 miles on the build so far and it still runs. I will prepare a backup engine block then, soon.

You all have been a massive help to me on such a noob question.
I really appreciate it!

 

[jed344]

The old saying goes with ring gap and piston to wall. Little to loose only you know, to tight everyone knows. I personally have used .0045 to 788whp at 45+ psi safely. Granted my ring gaps where .022 and .024 as i recall. Like said the bearing clearances is what factors oil weight.