The 2003 mustang cobra 327 stroker with 76mm turbo project begins

[ModularSpeed]

I hope it is not the case...really.

[mpe331lx]

Any updates on this?

[brian97cobra]

thanks for bringing this to my attention. so its been 4 months. here is a follow up for everyone.

install motor in may, got it tuned. then it was knocking after tune. pulled motor found cylinder #8 had damage. builder install 1 new piston and did a finish hone on the block. reinstalled "fixed" motor but then it still knocked until it warmed up. so took it back out. i finally pulled the motor again MYSELF!!!! last monday and i told builder to take motor down to the bare block and we are going to check EVERYTHING. i honestly dont know if i can take the stress of this crap breaking again. its had 0!!!! miles on it. im frustrated and exhausted to say the least.

so i hope to see all the parts in a few week and figure out what the hell is going on there. its just totally NUTS.


i brought that piston to the builder and he said ummm thats not supposed to look like that. so something else is wrong. also after doing some research perhaps the pistons were made wrong originally.

check out this build sheet. notice the piston pin offset difference... the card on the right was the 1 replacement piston. the one on the left is the original build sheet. then i also called diamond about this and they claim it was a misprint. but then also informed me that that piston does not like to see over 700 rwhp. it was a custom build and they were like yea i would have made the skirts thicker and ####. im like with you dumb asses spec'ed this piston for me and i asked for a "custom" design. needless to say i feel like breaking someones neck or something....

i may just part this bitch out and call it a total loss as i dont really feel like dealing with this much any longer. i just feel cheated and beat up.

here are a couple of pics of the suspension sorry for crapy cell phone pics.

on the positive note it took me 6 hours to pull the motor, trans, and turbo by myself. doing this so much ive become an expert at this...














picture of piston i took before install....









if anyone has any input or questions please post them up.

Originally Posted by ModularSpeed

That is unfortunate to hear.

Are you SURE that those marks are intentional on the skirt?

By looking at your piston, and seeing you say that they were weight matched.....why in the world is someone removing material from the less stable portion of the piston? I am not a rocket scientist, but it sure would make more sense IMO to remove an equal amount of material from the 4 corners in the center of the piston, as I drew here:



You can clearly see that the "witness marks" on that skirt, do not seem to be the optimal place to remove material from.

What people are asking is, is that contact from the counter weights on the crank?

It seems VERY odd that the "bad" piston that was slapping like a mofo, happened to feature this odd form of weight matching. Check this picture out, and you will see why people are asking:



It is very ironic, to say the least.....

Does the builder/machine shop have an account on this site? Maybe they can post about why they chose to modify that piston in such a way. I am always down for learning new tricks!

[brian97cobra]

Originally Posted by mpe331lx

Any updates on this?

thanks for the bump, i updated this on svtp but forgot to do this here....

[brian97cobra]

on a serious note. if someone is interested in the possible purchase of this car please let me know. im serious about selling it. im really tired of ####ing with it. it has 31k on the body and 0 miles on motor and trans and suspension work and turbo work. its a very clean car inside and out.

ive invested 26k in the motor trans suspension and turbo setup. make offers

[assasinator]

Originally Posted by brian97cobra

thanks for bringing this to my attention. so its been 4 months. here is a follow up for everyone.

install motor in may, got it tuned. then it was knocking after tune. pulled motor found cylinder #8 had damage. builder install 1 new piston and did a finish hone on the block. reinstalled "fixed" motor but then it still knocked until it warmed up. so took it back out. i finally pulled the motor again MYSELF!!!! last monday and i told builder to take motor down to the bare block and we are going to check EVERYTHING. i honestly dont know if i can take the stress of this crap breaking again. its had 0!!!! miles on it. im frustrated and exhausted to say the least.

so i hope to see all the parts in a few week and figure out what the hell is going on there. its just totally NUTS.


i brought that piston to the builder and he said ummm thats not supposed to look like that. so something else is wrong. also after doing some research perhaps the pistons were made wrong originally.

check out this build sheet. notice the piston pin offset difference... the card on the right was the 1 replacement piston. the one on the left is the original build sheet. then i also called diamond about this and they claim it was a misprint. but then also informed me that that piston does not like to see over 700 rwhp. it was a custom build and they were like yea i would have made the skirts thicker and ####. im like with you dumb asses spec'ed this piston for me and i asked for a "custom" design. needless to say i feel like breaking someones neck or something....

i may just part this bitch out and call it a total loss as i dont really feel like dealing with this much any longer. i just feel cheated and beat up.

here are a couple of pics of the suspension sorry for crapy cell phone pics.

on the positive note it took me 6 hours to pull the motor, trans, and turbo by myself. doing this so much ive become an expert at this...




picture of piston i took before install....
if anyone has any input or questions please post them up.

i use CP pistons.
of course i build and tune my own engines...but...

R&R does my balancing. they machine and build everything there is. they do not remove material from the skirt. ONE of my pistons was a few grams off and they removed material from the wrist area that others have illustrated.

[2MCHVNM]

Man, sorry about your ####ty luck. I just spent a huge amount of $ on my GT also (around $18k) on a beautiful custom 80mm kit from yaadman and a bunch of other ####, got the car down to RET in SoCal for a tune and it left with a bad knock that got much worse after about a 5 mile drive around the neighborhood when i got home.

The car is now sitting in my dad's shop covered in dust and likely being eaten by mice until i can afford to fix it (after a new roof on the house)

At least you married your girl and bought her a ring first! Mine is still waiting for her ring and not at all thrilled at the bill for my broken garage queen mustang!

Anyway, don't give up.... don't sell it and take a bath! Git'r dooone and enjoy it someday... you still have a badass car running or not, keep the faith!

[IUP99snake]

Don't worry, it'll all work itself out in the long run.

I had a built motor overheat within 20 minutes of running because the installer failed to bleed the coolant properly.

Out of money, I went to the junkyard and installed a Lincoln Aviator motor. Sure it wasn't forged, sure it was high compression, and yes, it was cheap... but it's the best running motor I've had in my car. Even after 70,000 miles of abuse from a Procharger. If I had the funds, I would have installed another built motor, but at the time, I was dead broke and just needed my car to run. Granted, my internals keep me from going above 450 WHP, instead of the 600 I was hoping to make with my built motor, but at least it runs.

There's just something about built modular motors I never have good luck with. They run best when they aren't messed with. (based on my experience.)

If I ever buy another built modular motor, even if I reuse some of my old parts, I'm going to hand it all off to a builder and let him do everything his way...then make sure it runs on an engine dyno before I take delivery of it.

[assasinator]

stroker crank.....longer counterweights?

stroker rods.....shorter rods for sure.

non stroker pistons?

even with stock dimension counterweights, shorter rods mean closer skirts.

[2000gtp1sc]

Originally Posted by assasinator

stroker crank.....longer counterweights?

stroker rods.....shorter rods for sure.

non stroker pistons?

even with stock dimension counterweights, shorter rods mean closer skirts.

I have very limited experience with building these motors, but wouldn't these clearance issues be noticed when turning the motor over by hand while putting it together? How did it make it into the car without showing signs of this "knock" by simply turning it over by hand?

Sorry for all of the problems you've had OP. It really blows when things don't go how you plan, but that's a lot of money down the drain to just give up and part it, imho. Good luck!

[assasinator]

Originally Posted by 2000gtp1sc

I have very limited experience with building these motors, but wouldn't these clearance issues be noticed when turning the motor over by hand while putting it together? How did it make it into the car without showing signs of this "knock" by simply turning it over by hand?

Sorry for all of the problems you've had OP. It really blows when things don't go how you plan, but that's a lot of money down the drain to just give up and part it, imho. Good luck!

rods compress under power.

[one_live95]

I'm going through something somewhat similar... Persevere. It'll make you love the car even more when it's its over. My 95 was the biggest PITA car if ever had when I did my build on it. But once hot it all worked out I absolutely loved that car.

Just my. 02¢

[2000gtp1sc]

Originally Posted by assasinator

rods compress under power.

I wondered about that. Kinda thought of it after I posted. Thanks for letting me know!

[brian97cobra]

yep motor has 4 bad pistons. #'s 1&5 and 4&8 all have skirt damage...

damn !!!

so i need new pistons and rings for sure.

the crank has no marks on it from where its hitting thats whats crazy not even a scrach.....

need a face palm pic inserted here

[Helomech74]

Just make sure that whom ever does the work this time checks that clearance. I've had to machine the crank before to clear the skirts, not much but still had to be done.

[Buds91LX]

Is this something that would be your fault per say and you have to eat the cost or did someoen els spec out the combo?

I hope it all works out. I had a small isue with my motor but I bough a long block so they eat it 100% and up graded me to a ALM block and gave me all gaskets and a 3 year warinty. This is why I leave that stuff to the pros.

[brian97cobra]

Originally Posted by Buds91LX

Is this something that would be your fault per say and you have to eat the cost or did someoen els spec out the combo?

I hope it all works out. I had a small isue with my motor but I bough a long block so they eat it 100% and up graded me to a ALM block and gave me all gaskets and a 3 year warinty. This is why I leave that stuff to the pros.

This is nothing I did wrong.

I pray it's covered 100%

This really has been a terrible experience for me. Don't think I'll ever have a mod motor built ever again. I'll go pushrod or just deal with stock ####.

[ModularSpeed]

Please list all of the people involved here, so people know what they could possibly encounter by following your same path.

I am truly sorry about this entire situation. If I were you, I dpn't know if I could have any faith in your combo. I gotta be honest, if I was in your position and let them fix the issue...the car would be for sale right after I got it tuned.

[ModularSpeed]

And, there wont be any marks on the crank. 4340 Steel VS 2618 Aluminum at those speeds, the 4340 doesn't even think about flinching.

Take some man pills, and ask who-ever doing the #### what those marks are. They are either going to know, or they are not. NO MATTER what they say, it's a bad thing....so, you may as well get a correct answer....

[brian97cobra]

Originally Posted by ModularSpeed

Please list all of the people involved here, so people know what they could possibly encounter by following your same path.

I am truly sorry about this entire situation. If I were you, I dpn't know if I could have any faith in your combo. I gotta be honest, if I was in your position and let them fix the issue...the car would be for sale right after I got it tuned.

im not one to create a smear campain here. i need to let the people working on this make a good faith effort to repair the issues. at this point i dont see this being my fault at all and i hope to not pay another dime for repairs.

im going to keep this thread updated and post all results when done (god i pray this thing gets done)

its got the best of the best in this build. i would lose my ass selling it. i personally just want another whipple cobra either a 2.3L or the new 2.9L. i love the sound of a turbo but man this has been HELL.

i honestly jusy pray in the end all is well and i can actually enjoy my car.

[ModularSpeed]

I pray for you too. It is situations like this, that ruin this hobby for some. This is why I started sticking with simple builds. Stock motor stuff.

Even if they cover everything, it's to the point where "they" should start paying you for your time and effort....

[serpentnoir]

Originally Posted by brian97cobra

This is nothing I did wrong.

I pray it's covered 100%

This really has been a terrible experience for me. Don't think I'll ever have a mod motor built ever again. I'll go pushrod or just deal with stock ####.

This has nothing to do with pushrod, mod or stock. Judging from your posts you are way out of your league on this build. Motors like that should be built by the owner. This way there is no finger pointing. If the owner doesn't have the expertise he should lower his expectations, simplify the project and gain experience then build on that. In this case your builder learned on your dime.

[ModularSpeed]

Originally Posted by brian97cobra

ok well we have found at least 2 major issue.

i have 4 bad pistons because of a clearance issue.

the crank counter weights are hitting #'s 1,4,5,8 pistons... so def need an entire set of pistons.

gonna need to either shave the crank or get some pistons with different skirt lengths.

also gonna go down to 4 thous side wall clearance instead of the 5 that was on there.

praying that this fixes my car...

what funny is that when you spin the motor over by hand before it was installed it never hit. also the crank has no marks on it from the pistons hitting hit at all, i mean not even a scrach... its damn crazy!

Just updating this thread....

So the crank and pistons made love, like I and a few others already knew.

Did you pick the combination of parts? I saw where you said you chose a 3.8" crank instead of the 3.75" What length rods?

Brian, I will say this. I had en engine years ago that I put together when I was a newb, that made awesome power for about a year. It started making noises, and I discovered beat up pistons (same issue as you had/have) AND valve marks on every piston.... Keep your head up.

[brian97cobra]

Originally Posted by ModularSpeed

Just updating this thread....

So the crank and pistons made love, like I and a few others already knew.

Did you pick the combination of parts? I saw where you said you chose a 3.8" crank instead of the 3.75" What length rods?

Brian, I will say this. I had en engine years ago that I put together when I was a newb, that made awesome power for about a year. It started making noises, and I discovered beat up pistons (same issue as you had/have) AND valve marks on every piston.... Keep your head up.

so im clear here.

i called pro power and ordered this kit and they spec'ed out the rods, pistons, crank, rings.

they called me back and stated that the crank for the 3.750 was on back order at the time. so i went with the 3.800.

the rod length is 5.850 manley billet I-beam.

[brian97cobra]

Originally Posted by serpentnoir

This has nothing to do with pushrod, mod or stock. Judging from your posts you are way out of your league on this build. Motors like that should be built by the owner. This way there is no finger pointing. If the owner doesn't have the expertise he should lower his expectations, simplify the project and gain experience then build on that. In this case your builder learned on your dime.

how exactly am i out of my league here?

i didnt build this motor. nor did i dyno it

i simply pulled old motor sold it and installed motor that i PAID someone to build for me. i also installed the turbo kit. i PAID someone to weld in my suspension components.

so what league do i need to be in ?....

[ModularSpeed]

Gotcha, definitely clears everything up. So you ordered the rotating assembly through/from Pro-Power, and gave the parts to Tim Matherly to build the engine, all parts were new.

I think what serpentnoir was getting at, is, people should not be surprised to have these issues when using multiple people/shops on a high(er) end build like this. On paper, I guess he is right due to us posting about the catastrophe. I see your point Brian, and it is ashame that someone can have these issues when they are supposedly using the cream of the crop for their services.

May be a while but, can't wait to see her done! Definitely one of the cooler builds on the forums sir.

[brian97cobra]

Originally Posted by ModularSpeed

Gotcha, definitely clears everything up. So you ordered the rotating assembly through/from Pro-Power, and gave the parts to Tim Matherly to build the engine, all parts were new.

I think what serpentnoir was getting at, is, people should not be surprised to have these issues when using multiple people/shops on a high(er) end build like this. On paper, I guess he is right due to us posting about the catastrophe. I see your point Brian, and it is ashame that someone can have these issues when they are supposedly using the cream of the crop for their services.

May be a while but, can't wait to see her done! Definitely one of the cooler builds on the forums sir.

Well thanks for the compliment.

It's def been an eventful build and a hell of a learning experience for me.

[WheelStander]

Well fwiw you probably saved me much heartache as I was going to rip mine down and go for 700hp.

I'll be happy with 500 and call it a day and just enjoy a stock motor.

That being said this is going to be one bad ax ride when you are done.

Hang in there bro.

Posts and experiences are greatly appreciated.



Sent from my iPhone using AutoGuide.com Free App

[ARCANGL]

i def didnt read all 6 pages of this thread...

but i have one question, we all know it was obviously counterweight to piston clearance... but i dont think it was a clearance issue.
I think piston rock caused it to rub.
Which leads to my question... why are you running 50 thou in a motor where Diamond spec'd 35 thou?? And even now you are still gonna run 40.
That just causes piston stability issues, and could cause enough rock for such a tight motor to rub.
JMO

[brian97cobra]

Originally Posted by WheelStander

Well fwiw you probably saved me much heartache as I was going to rip mine down and go for 700hp.

I'll be happy with 500 and call it a day and just enjoy a stock motor.

That being said this is going to be one bad ax ride when you are done.

Hang in there bro.

Posts and experiences are greatly appreciated.



Sent from my iPhone using AutoGuide.com Free App

Don't be scared to have a motor built. There are a lot running around that work just fine. Mine however was not. But it will be soon enough.

[brian97cobra]

Originally Posted by ARCANGL

i def didnt read all 6 pages of this thread...

but i have one question, we all know it was obviously counterweight to piston clearance... but i dont think it was a clearance issue.
I think piston rock caused it to rub.
Which leads to my question... why are you running 50 thou in a motor where Diamond spec'd 35 thou?? And even now you are still gonna run 40.
That just causes piston stability issues, and could cause enough rock for such a tight motor to rub.
JMO

Great question.

When I called diamond they said 3.5 tho to 4 tho clearance. At my power level 4 tho is where I think it should be.

[Helomech74]

Just to clarify, if you are indeed running a 3.8" crank, then the pistons need to be custom spec'd for that. The rod length is still 5.850 like a 3.75 crank, but the piston skirts are usually cut down for clearance or the wrist pin is moved. It appears that those pistons were spec'd for a 3.75" crank, which caused your crank/piston skirt interference issue. I would lay the blame on the folks that put the package together first and then the builder for not checking this clearance. I've never had a piston kiss the crank like that, but I always check that clearance when I build a motor, especially a stroker.

[ARCANGL]

those are def a 3.80 spec'd piston... look how the piston pin interferes with the oil control ring land.
And the piston would come out of the top of the bore in they werent spec'd correctly, not just cause interference at the crank.

also on his piston sheet it says compression height is 1.185, look for normal pistons they are usually 1.220/1.215

here are my diamond pistons spec'd for 3.80... they look identical except mine are coated

[Helomech74]

That pin location isn't only on 3.8" pistons. I just built a motor with a 3.75 crank and my pin also interferes with the oil control ring. I know that CP pistons were used in some of the original 3.8" stroker kits and they used cut down skirts as opposed to a different pin location.

Here's a pic of my custom Manley. It's for a 3.75" crank, BB motor.

[ARCANGL]

thats why i also listed his compression height...