7 bolt rebuild question...

[Jammin'Trey]

Hey guys, my 7 bolt has 146k miles and compression numbers of 151, 160,150,130. I want to pull the head and oil pan, take out the pistons and rods, put new bearings on the rods and re-ring the pistons and take a hone to the cylnders. I planning on stock mitsubishi gaskets, bearings and rings.

The question I have is should I look into installing new valves, springs and retainers? I am putting in new timing belt, balance belt, tensioner, and DKS 272int/ex cams. I have a 14b, pte 1000cc injectors, walbro 255, fuelab 515 afpr, link v2.5, full 3in. Car has been professionally tuned by a local dsm shop.

Will this bring my compression numbers up? I want to do this in my garage in about a weeks time.

I run 20psi daily, I do have arp headstuds already in the car. I assume they will need to be replaced when I take the head off. The previous owner of the car ran it on e85 and I beleive over 20psi boost.

 

[DeNoZZo]

Hey guys, my 7 bolt has 146k miles and compression numbers of 151, 160,150,130. I want to pull the head and oil pan, take out the pistons and rods, put new bearings on the rods and re-ring the pistons and take a hone to the cylnders. I planning on stock mitsubishi gaskets, bearings and rings.

The question I have is should I look into installing new valves, springs and retainers? I am putting in new timing belt, balance belt, tensioner, and DKS 272int/ex cams. I have a 14b, pte 1000cc injectors, walbro 255, fuelab 515 afpr, link v2.5, full 3in. Car has been professionally tuned by a local dsm shop.

Will this bring my compression numbers up? I want to do this in my garage in about a weeks time.

I run 20psi daily, I do have arp headstuds already in the car. I assume they will need to be replaced when I take the head off. The previous owner of the car ran it on e85 and I beleive over 20psi boost.

New piston rings would most definately raise whatever piston has 130 up in compression

 

[FLASH1970]

Did you do a leak down test? I would do that before tearing apart the engine. It might just be a headgasket or maybe a valve. If you do rebuild the engine, do it right. Pull it out and get it machined.

Better yet, take a couple months building a 6-bolt short block or longblock and just swap that in over a weekend when it's done.

 

[JEFFREYCASTGSX]

Did you do a leak down test? I would do that before tearing apart the engine. It might just be a headgasket or maybe a valve. If you do rebuild the engine, do it right. Pull it out and get it machined.

Better yet, take a couple months building a 6-bolt short block or longblock and just swap that in over a weekend when it's done.

Dont waste your time on a 6-bolt, the ONLY thing thats really gonna help you is the stronger rods. Just keep on with the superior 7-bolt.

 

[lacroixdp]

Dont waste your time on a 6-bolt, the ONLY thing thats really gonna help you is the stronger rods. Just keep on with the superior 7-bolt.

Stronger rods, beefier crankshaft, thicker head bolts, superior head flow for track use, better oil squirters, and a better reliability record. Really, why do you continue to argue with everyone that recommends going with a 6bolt? It's a completely valid recommendation from someone that obviously knows the benefits better than you do. Hell, even you have a 6bolt in your 2G.

 

[GSXSixteenG]

New rings will help your compression if that's what is causing the low compression in the one cylinder. But do a leak down test first to make sure before you start ripping it apart. If you taking it apart, might as well get some 1g fat rods.

You don't necessarily need to replace valves, springs, and retainers. Depends on what kind of goals you are trying to reach. The 14b will probably be maxed before you reach the limits of those components. A 1g head isn't a bad thought if your up to the tasks for the better flow.

 

[BogusSVO]

if you have the high milage stock valve springs, I would say swap them out. and if you go with aftermarket cams.... you will have too to a spring swap.