3v engine build! HELP!!!!

[-ZeusOfBoost-]

Hey guys, I'm currently building a high compression short block for my turbo '05, I bought a set of Manley #594020 flat tops, these flat tops are completely flat on the top, no valve relief. Is this gonna be a issue? There the same compression height as the rest of the flat tops that are designed for a 3v just doesn't have any reliefs. I've heard that the 3v doesn't need a relief until .550 or more lift cam.

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[weather man]

Manley does not spec those for 4.6 3V engines. I would contact them and get their opinion. If you get it wrong, pretty expensive lesson.

 

[lito]

If you are locked or limited, no need for valve pockets.

 

[dysan]

I don't have a high lift cam, just the .490 lift comp 127300's but with my VCT locked out and no reliefs for valves there was a ridiculous amount of room. My engine builder put putty on the piston top and turned the crank and the valve never even touched the putty.

 

[weather man]

I don't have a high lift cam, just the .490 lift comp 127300's but with my VCT locked out and no reliefs for valves there was a ridiculous amount of room. My engine builder put putty on the piston top and turned the crank and the valve never even touched the putty.

Good post, thanks for sharing that.

 

[-ZeusOfBoost-]

Awesome guys!!! Thanks a ton! Got a steal on these pistons, and I was like... Well shit... Didn't think of that issue.

On another hand, I planned on breaking the engine in on stock cams before I go with a custom grind from Bullett and lockouts, will I be fine with the stock as well? I'd think so.


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[lito]

Awesome guys!!! Thanks a ton! Got a steal on these pistons, and I was like... Well shit... Didn't think of that issue.

On another hand, I planned on breaking the engine in on stock cams before I go with a custom grind from Bullett and lockouts, will I be fine with the stock as well? I'd think so.


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Not with a stock tune and non locked/limited cams, there are moments where the retard goes to 60degreees and PTV could occur, so no.

 

[-ZeusOfBoost-]

What if I lock out the stock cam? It'll be on a break in/start up tune. I do already have the lock outs, just didn't think a stock cam would need them.


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[lito]

What if I lock out the stock cam? It'll be on a break in/start up tune. I do already have the lock outs, just didn't think a stock cam would need them.


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No problem there.

 

[TexasBlownV8]

Why not just break it in with the cams you are going to be using? (unless you don't have them yet)

 

[-ZeusOfBoost-]

I actually don't have them yet, I was gonna do the cams, new turbo and coldside and bigger fuel system after break in, I figured it would be easier to break it in on a smooth idling cam with 47# injectors other than 100# injectors and a big cam trying to get it to idle lol.


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[AutoXRacer]

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[-ZeusOfBoost-]

It's a 76mm turbo car.


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