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420a stock capabilities

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syquest15

Probationary Member
11
0
May 7, 2008
saint paul, Minnesota
hello all,

I was having a lovely conversation with a buddy and we were talking about what he is going to do with his ride. He pretty much is about to take the cheapest road possible and i basically laughed at him for saying such. He called up a performance shop that rebuild his engine for him ( with forged lower internals but stock up top ) and they told him the car could handle 300 hp easy just like it is, with a turbo being slapped on to make it that 300 hp ( from the ~160 ) hp it is now.

I told him that he runs a superb chance on blowing some of his upper internals if he does this, cause stock isnt made to handle the stress, especially on a n/t stock car. I told him if he didnt want to rebuild the top half, he would be running at about a safe 225hp with not taking a huge chance at blowing the stock internals. ( original cams, lifters, valves,etc... 140k miles worth of wear on them too)

anyone have some input on this? as much as i would like to see him shoot a rod through his engine, im afraid i would be the one ripping it out :( so I guess I am being proactive to myself haha!

I will be bringing him here to show him this thread. I told him he should take this in steps, but he wants power without the $10k investment. I said the only way you do that is with taking chances, and can easily lose those chances.
 
Simply put he will blow his motor in no time. He needs to upgrade both rods and pistons and get some 8.5 or 9.0 compression pistons, along with a thicker head gasket and arp head studs to hold the boost without blowing anything out in the motor, then on top he would have to also consider into a bigger fuel pump and injectors and a device to tune with or else that turbo he slaps on wont make a difference for crap. Hope you can knock some sense into him.
 
Simply put you are wrong and your friend and his shop are right. You do not need to upgrade your head to safely make 300whp on a 420a motor with built bottom end. He will need fuel and tuning tools to make the power but in handeling the power a built bottom end with low compression pistons and stock head is fine. Hell a stage 2 Hahn kit makes 225whp on stock everything.
 
That's what i just said. Only i rather spend the extra xcash on reinforcing my top and bottom both and save headaches later down the road. I think long-run.
 
Simply put he will blow his motor in no time. He needs to upgrade both rods and pistons and get some 8.5 or 9.0 compression pistons, along with a thicker head gasket and arp head studs to hold the boost without blowing anything out in the motor, then on top he would have to also consider into a bigger fuel pump and injectors and a device to tune with or else that turbo he slaps on wont make a difference for crap. Hope you can knock some sense into him.

He already upgraded both. He stated that in his first post that his friend has a built bottom end. You don't blow upper internals which is more comonly called valve train parts. There are guys on here that make good power with bone stock heads.
 
Dont doubt Slippi84 he knows his stuff...... I agree with what he said, With a built bottom end, (as long as its tuned right) 300hp will not hurt the valve train.
 
Sorry i forgot about that part he stated in his thread LOL, i reject my statement on to get top end parts as he obviously already has it. Wow my memory is real bad i need some memory counseling or something WTF
 
Sorry i forgot about that part he stated in his thread LOL, i reject my statement on to get top end parts as he obviously already has it. Wow my memory is real bad i need some memory counseling or something WTF

I easily misread the first post of the thread to, LOL. I agree with slippi too, the stock head can handle 300+, it's the bottom end that could not handle the turbo conversion ( if not tuned right).

The reason I add that last statement is because awddynamite ran with stock everything for a whole year and ran high 11s before he changed to forged internals. He never blew the stock motor just decided on upgrading because he wanted to run low 11s. He knew how to tune his fuel setup real well...

But going back to the main point, the car can handle 300+ just fine with a stock head.
 
But to the Op's defense just "slapping on a turbo" as in turbo and manifold with ic setup will not make for a long lasting car. The diffrence between a stage 1 and 2(hahn style) kit isn't even really the turbo and fmic as much as the supporting mods and tuning. Things like missing link FCD MSnS are all things you want to look into when going from NA to NA-T.
 
But to the Op's defense just "slapping on a turbo" as in turbo and manifold with ic setup will not make for a long lasting car. The diffrence between a stage 1 and 2(hahn style) kit isn't even really the turbo and fmic as much as the supporting mods and tuning. Things like missing link FCD MSnS are all things you want to look into when going from NA to NA-T.

Very true, Fuel system and engine monitoring tools will be the main factor to how long that motor holds up, since we don't have a PnP Ecu to replace...yet...
 
appreciate the input so much guys. I didnt realize the stock internals could handle double the hp from factory setting.

I have always gone with the theory better safe than sorry, but i guess in his case we will get to try it out first hand now LOL
 
appreciate the input so much guys. I didnt realize the stock internals could handle double the hp from factory setting.

I have always gone with the theory better safe than sorry, but i guess in his case we will get to try it out first hand now LOL

You keep saying internals? People don't refferto the head whenthey say stock internals. They are talking about the pistons rods and sometimes cank. Your friend said he had forged pistons and rods correct? If so he is no longer stock he has a built shortblock. You are referring to a long block which is head and block built. It's not as relevant but the 4g63t comes with 210 crank hp stock people have pushed it to 500whp and slightly over in with tock shortblock(internals). Food for thought.;)
 
I am selling my built motor if he wants a BUILT motor. Keep in mind, some people blow their motor at 5psi and others run 12psi for a couple of years and nothing messes up; it's more of what condition his motor is in and the amount of maintenance done to it, along with the tune. If interested in my motor send a PM or look in the classified.
 
Guys, it's cool to say "if you're looking for a motor, send me over a PM," but we can't allow links to classifieds, member's eBay auctions or the like. Just remember the intent of most of our rules is to keep forum technical information streamlined and clear of clutter.
 
People that blow their motors with 5 and 12 psi are stock long block guys this guy ALREADY has a built shortblock. I should say had as this is again a acient thread.

This thread was started yesterday, I don't see how that is ancient. The user just joined this month, of this year.


appreciate the input so much guys. I didnt realize the stock internals could handle double the hp from factory setting.

I have always gone with the theory better safe than sorry, but i guess in his case we will get to try it out first hand now LOL

And this is what leads me to believe he still has a stock motor.
 
I believe Hahn had the stock valve train up to 500 hp did he not? Anyways like slippi said the head will be fine stock. If he builds the bottom end and slaps on a turbo with all the supporting items he will have no problem boosting until his heart is content assuming he knows his tuning.
 
This thread was started yesterday, I don't see how that is ancient. The user just joined this month, of this year.

I think he got a little mixed up with the other thread you guys where arguing in....


And this is what leads me to believe he still has a stock motor.


If you notice he was talkin about the valve train, Which he keeps calling internals which is confusing....
 
This thread was started yesterday, I don't see how that is ancient. The user just joined this month, of this year.




And this is what leads me to believe he still has a stock motor.

Sorry I mixed this thread up with the other one that was dug up that you nd I were posting about. ANd like car guy said he calls valve train parts internals which is why you probably think that but read his first post and you will see differently;)
 
I believe Hahn had the stock valve train up to 500 hp did he not? Anyways like slippi said the head will be fine stock. If he builds the bottom end and slaps on a turbo with all the supporting items he will have no problem boosting until his heart is content assuming he knows his tuning.

Very well said. Hahn has done all the research on the 420a and it is posted on their website. The 420a motor is a pretty good motor assuming that you have running the correct fuel to match the additional air.

http://www.turbosystem.com/auto/engine/Portfueler.htm <--Read under the dyno chart. Stock valves, cams, and head.....380whp
 
Very well said. Hahn has done all the research on the 420a and it is posted on their website. The 420a motor is a pretty good motor assuming that you have running the correct fuel to match the additional air.

http://www.turbosystem.com/auto/engine/Portfueler.htm <--Read under the dyno chart. Stock valves, cams, and head.....380whp

I did read that's why I posted that the valve train was fine in my first post ;)
 
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