rebuild: what option does everybody take?

[MLS]

I am using my stock timing cover with my C head WAP swap.

 

[Attaus]

I have the Probe "Dominator" series engine that decided to shed it's timing set on one side.. so I just ordered some new parts.

I went with the base Clevite bearings, Total Seal Moly rings, and eventually new HG, etc. I wanted to be able to throw a turbo at it down the road but not spend a fortune on internals ($500 on rings and bearings). The guy at the Modular Head Shop told me that the Moly rings would be good up to 600hp at the crank, which is the max my trans, diff, axles etc can take, so I'm happy with that. Cost me $250 or so.

 

[IronSnake]

Bought a spun bearing 01 cobra motor for 900. Rebuilt it for 300. Sold the heads. Bought a lower mileage set of 99 heads and cams. Used the 01 intake and put it in the car. Wouldn't have any other motor than a C head. Best power band ever

 

[encasedmetal]

I thought 03/04 timing covers line up on a teksid but there's ONE bolt that doesn't.

AND? grab some rtv and move on.

 

[na svt]

I also think the 03 cobra cams are more mild than a stock NA cobra? I'm not positive and maybe someone else might be able to tell you for sure,

03/04 cobra intake cams have 14 degrees less duration than the 96-98 intake cams.

 

[na svt]

The guy at the Modular Head Shop told me that the Moly rings would be good up to 600hp at the crank, which is the max my trans, diff, axles etc can take, so I'm happy with that. Cost me $250 or so.

So rings have hp limit...bullshit. Rings do not have a hp limit.

 

[IronSnake]

Sometimes NA SVT I wonder how many times you'll need to post the true facts about the stock cams for it to be common knowledge. I can't count on both hands the number of times you've said it on here that I've read. lol.

Not knocking those unaware, it's just a small thing I've noticed.

 

[Attaus]

So rings have hp limit...bullshit. Rings do not have a hp limit.

Why not? From what I heard the moly rings begin to flake under certain stress. Granted when everything is tuned correctly and hunky dory you might not have issues with even OEM parts but that's not the point. It's all about being able to withstand the inevitable lean/hot circumstances.

But from what I hear, you know your stuff, so I would like to hear your input.

 

[encasedmetal]

Why not? From what I heard the moly rings begin to flake under certain stress. Granted when everything is tuned correctly and hunky dory you might not have issues with even OEM parts but that's not the point. It's all about being able to withstand the inevitable lean/hot circumstances.

But from what I hear, you know your stuff, so I would like to hear your input.

moly rings have a boost limit imo, and the block finished usually around a 280 grit for moly. HP has little to do with the "limit" of anything in your motor- the limiting factor of most materials in the motor is determined by stress, whether by rpm, boost, combustion efficiency, tolerances etc.

 

[na svt]

HP has little to do with the "limit" of anything in your motor- the limiting factor of most materials in the motor is determined by stress, whether by rpm, boost, combustion efficiency, tolerances etc.

Exactly.

 

[Attaus]

moly rings have a boost limit imo, and the block finished usually around a 280 grit for moly. HP has little to do with the "limit" of anything in your motor- the limiting factor of most materials in the motor is determined by stress, whether by rpm, boost, combustion efficiency, tolerances etc.

You're saying if I run a T25 at 35lbs I'm risking my motor more than a T88 at 12 lbs? Boost pressure might blow out some intake seals but other than the additional air makes no difference to the engine. Combustion produces a lot more force than boost pressure, I promise you that.

Now if you want to argue that volumetric flow effects engine stress I can agree to that, but it is directly proportional to the amount of horsepower. Horsepower per liter is a great way to measure stress vis a vis the amount of force delivered per area.

Generally saying Moly rings are good to 600hp or some arbitrary number isn't the best way to say it, a better way would be up to x HP/L, but it is a simplified way of showing what the engine you are ordering parts for can handle.

Literally every performance engine or part calls out its limit in HP. Not RPM, not boost level (which is silly), and not VE. Are you really suggesting all of them are wrong?

 

[Livernois Motorsports]

I want to stay N/A. I don't have any plans for anything crazy. 400 rwhp would be a good goal to set.

Hey Fake, just thought I'd pop in and introduce our shop since we were mentioned. We actually have a 298 cubic inch modular stroker short block that is on clearance. Here is the link with the breakdown of it.

http://www.svtperformance.com/forum...livernois-pro-series-modular-short-block.html

Feel free to PM me with any questions about your goals or for any advice. Look forward to speaking with you. -Chris

 

[encasedmetal]

You're saying if I run a T25 at 35lbs I'm risking my motor more than a T88 at 12 lbs? Boost pressure might blow out some intake seals but other than the additional air makes no difference to the engine. Combustion produces a lot more force than boost pressure, I promise you that.

Now if you want to argue that volumetric flow effects engine stress I can agree to that, but it is directly proportional to the amount of horsepower. Horsepower per liter is a great way to measure stress vis a vis the amount of force delivered per area.

Generally saying Moly rings are good to 600hp or some arbitrary number isn't the best way to say it, a better way would be up to x HP/L, but it is a simplified way of showing what the engine you are ordering parts for can handle.

Literally every performance engine or part calls out its limit in HP. Not RPM, not boost level (which is silly), and not VE. Are you really suggesting all of them are wrong?

not neccessarily wrong- just misinforming the general public. very similar to forum statements about what hp on pump 93oct is dangerous. There are so many factors that go into the "HP" limit of a product. and yes I would venture to say that your theoretical 35psi will find a fault in the motor before 12psi will- think rings, valve springs, seats, head gaskets etc. I know you want to argue but the best example I can give you is to think of 2 identical motors except the compression on one is 10:1, and the other is 15:1. Both sets of pistons, rods, crank, etc are identical material therefore the "HP" limit is theoretically the same. Now tell me which is gonna blow first on an 8000 rpm pull given all factors are the same. extreme example but trying to get my point across. same thing with the 03/04 rods, the "HP" limit goes up alot by only replacing the stock ARP rods bolts with ARP 2000 rod bolts, which has nothing to do with the rod itself- it's to do with clamping load and bolt stretch. You and others on here need to realize that most companies are trying to get your money by using said "HP" statements- and they will too.

 

[na svt]

You and others on here need to realize that most companies are trying to get your money by using said "HP" statements- and they will too.

Once again I agree.

 

[Attaus]

not neccessarily wrong- just misinforming the general public. very similar to forum statements about what hp on pump 93oct is dangerous. There are so many factors that go into the "HP" limit of a product. and yes I would venture to say that your theoretical 35psi will find a fault in the motor before 12psi will- think rings, valve springs, seats, head gaskets etc. I know you want to argue but the best example I can give you is to think of 2 identical motors except the compression on one is 10:1, and the other is 15:1. Both sets of pistons, rods, crank, etc are identical material therefore the "HP" limit is theoretically the same. Now tell me which is gonna blow first on an 8000 rpm pull given all factors are the same. extreme example but trying to get my point across. same thing with the 03/04 rods, the "HP" limit goes up alot by only replacing the stock ARP rods bolts with ARP 2000 rod bolts, which has nothing to do with the rod itself- it's to do with clamping load and bolt stretch. You and others on here need to realize that most companies are trying to get your money by using said "HP" statements- and they will too.

But why does a 15:1 compression ratio motor fail? The fuel can't support it.. or it's poorly tuned.. or for the simple fact that people realize it's not worth the effort to tune correctly and there's no room for error. Diesels run 17:1 compression and 30lbs of boost, yet use cast pistons. Explain to me how this is possible with, according to your definition, motor-shredding compression and boost levels, and I will believe you.

I agree that horsepower is a very simplified way of expressing a parts abilities. However, UTS and UYS do not translate to the public. No one will understand or care what happens when a material reaches its recrystallization temperature, or that repeated abuse of an engine will literally anneal a poorly made part. Horsepower designations are used because horsepower is obviously a measure of force, and used as a "safe" level. Of course things can be pushed past that. However, any good manufacturer knows at what temp their material drops off in strength, and it doesn't take a motor long to get hot enough to reach it. Once they do, certain exotic materials maintain 70-80% of their ambient strength, and you will see no issues. Cheap or poorly made parts.. won't. You reach that temp (repeatedly), or once very quickly, and parts fail even faster.

Compression and boost level by themselves will not destroy an engine. Their resultant, horsepower, does. As temperature rises that force will find the weak points in your build very quickly.

It's not the power the part can handle and maintain. It's the power the part can maintain during an inevitable lean condition, poor tune, bad batch of gas, etc. A stock piston in a Teksid might withstand 600hp when everything is tuned correctly, but when it runs lean it will go. A forged piston made to withstand that power will not (in most cases).

It's not a guarantee that your engine will be good for that power. It's more of a guideline. But it's more accurate than running compression and boost levels, because that won't explain anything. Think of them as an input, not an output.

I don't mean to badger you but I genuinely enjoy discussing these things. I'm going to school for it, so I ought to I guess.

 

[encasedmetal]

But why does a 15:1 compression ratio motor fail? The fuel can't support it.. or it's poorly tuned.. or for the simple fact that people realize it's not worth the effort to tune correctly and there's no room for error. Diesels run 17:1 compression and 30lbs of boost, yet use cast pistons. Explain to me how this is possible with, according to your definition, motor-shredding compression and boost levels, and I will believe you.

I agree that horsepower is a very simplified way of expressing a parts abilities. However, UTS and UYS do not translate to the public. No one will understand or care what happens when a material reaches its recrystallization temperature, or that repeated abuse of an engine will literally anneal a poorly made part. Horsepower designations are used because horsepower is obviously a measure of force, and used as a "safe" level. Of course things can be pushed past that. However, any good manufacturer knows at what temp their material drops off in strength, and it doesn't take a motor long to get hot enough to reach it. Once they do, certain exotic materials maintain 70-80% of their ambient strength, and you will see no issues. Cheap or poorly made parts.. won't. You reach that temp (repeatedly), or once very quickly, and parts fail even faster.

Compression and boost level by themselves will not destroy an engine. Their resultant, horsepower, does. As temperature rises that force will find the weak points in your build very quickly.

It's not the power the part can handle and maintain. It's the power the part can maintain during an inevitable lean condition, poor tune, bad batch of gas, etc. A stock piston in a Teksid might withstand 600hp when everything is tuned correctly, but when it runs lean it will go. A forged piston made to withstand that power will not (in most cases).

It's not a guarantee that your engine will be good for that power. It's more of a guideline. But it's more accurate than running compression and boost levels, because that won't explain anything. Think of them as an input, not an output.

I don't mean to badger you but I genuinely enjoy discussing these things. I'm going to school for it, so I ought to I guess.

I get the strong feeling we're both trying to say the same thing but expressing it in very different ways. kudos to you for going to school to expand your knowledge on the subject. As for the diesel statement- I would attribute it to the fuel used itself, such as with E85 and it's combustion characteristics. not badgering me at all-it's refreshing to converse on a subject that's not the norm for this forum.

 

[Attaus]

I get the strong feeling we're both trying to say the same thing but expressing it in very different ways. kudos to you for going to school to expand your knowledge on the subject. As for the diesel statement- I would attribute it to the fuel used itself, such as with E85 and it's combustion characteristics. not badgering me at all-it's refreshing to converse on a subject that's not the norm for this forum.

:beer: