Re-Ring/Bearings or....?

[AcIdBuRn02ZTS]

Hey guys...

Been a long while since I've been on. I parked my '87 last year after blowing a hose on the highway and losing the headgasket shortly there after. We since moved and remodeled a house so the car was on the back burner until now.

I finally got around to pulling the head today and what I found is bothersome. I bought the car and drug it out of a field in which it had been sitting for 5+ years untouched. I got it running and drove it for several months off and on with no real issues... No blowby, etc.. Had 130k on the odometer.

Anyways... Pulled the head and found corrosion in cylinders 2, 3, 4, and 5. No rust and no pitting... But midway down the bores, there is a lip that can be felt with a fingernail. I'm assuming this is where the pistons were sitting for years before I brought it home...

I have no options for a machine shop that I trust in the area so hand honing and re-ringing is my only real choice. I can't even find a local shop that can tell me the RA value of their surface grinders... So felpro headgasket and studs are again my only choice.

The plans for the car are 350-400whp... Just a fun street car. I'm sure the headgasket with studs will be fine... I'm just worried about the bottom end refresh.

Planning on honing to clean up the bores... NPR rings, federal mogul bearings, new oil squirters... Then most likely a clutch upgrade while its all apart.

Does this sound like a decent plan?

I already have the gasket set, head studs, water pump, timing set, and a new downpipe... So all I should need is bearings, rings, squirter bolts, and bottom end gaskets.

Ideas, opinions, etc..?

Thanks
-Chris

 

[hvyman]

Could just travel farther for a good machine shop. depending how deep it is could need to be bored.

Also could be scoring from the pistons and they could be damaged as well.

 

[suprarx7nut]

If you're aiming for that much power I'd go the extra distance for a good machine shop. If you're ok with lower 300's for whp then it's a simpler project. Above low 300's whp you need enough other supporting mods that I think it would be foolish to skip a proper block prep from a machine shop - especially given that you have noticeable wear and/or corrosion.

That's my 0.02 anyway.

 

[AcIdBuRn02ZTS]

I haven't pulled it apart yet but will be in the next couple of weeks. At that point (if major machine work is needed), I would most likely just go the route of swapping do a different platform. I searched out a decent machine shop that had experience with the 7m in my area and there are none. By the time I drive several hours or ship it out and have the block fully reworked, including parts, I could go with a different platform.

Or... I could hone it out to the point of getting the bores clean and snap gauging them to make sure they are in spec. The factory hone marks are still visible in the bores but there is a lip still. (The problem area is almost a very slight protrusion into the bore.. a high spot on the cylinder wall) I may just try it and see if they will clean up... cant really hurt anything.. if they need to be bored.. they need to be bored.

Now... as far as supporting internal mods to support north of 300whp... what I needed? I've seen quite a few guys running composite gaskets with studs and stock internals over 400whp... but if thats not the route to take.....

Again, not looking for a high end build and I dont have the coin to sink 1500-2k into this 7m... so what are my options?

Thanks for the input guys.

-EDIT-

If anyone knows of a GOOD machine shop that has 7m experience in the Southern IN area, please let me know.

 

[suprarx7nut]

I think a machine shop can do fine work on a 7M without having specific expertise on the platform. It's nothing too crazy exotic. Although... you are in the part of the country where I'm sure there are shops that have very limited experience on imports of any variety.

Anyways... In my mind the 7M has a pretty significant step change in what's required to meet certain power levels. In my own off the cuff terms here we go:

Stage 1: Fuel cut occurs at around 300-320 whp from what I can gather. To get a 7M up to fuel cut power levels you don't need much. Exhaust and a boost controller is really all that's required. At that point you're not running anything that changes how the car normally drives. All the intricate parts and systems can remain fully intact and functional. At this stage a composite head gasket is totally fine. No special block prep is needed provided you have a relatively clean block. The head should be milled flat, but that's a job most any machine shop can handle with ease. Stock intercooler is fine. Full face clutches work well at this stage and drive ability is nearly identical to stock.

Stage 2: Piggyback systems. 300-500? To get past fuel cut you need to trick the ECU. To do this you generally need to up your fuel capability. One easy route to take here is the Lex AFM and 550 injector mod. Along with this you should replace the fuel pump with something that can flow more. You should also use a piggyback ECU or other tuning device to ensure you're not too far off the factory tune. You can run with just the 550's and Lex AFM, but you should be cautious. At this stage you'll want a larger turbo (even if you're using just a modified CT-26). The headgasket should probably be metal at this point. You may be ok with a composite, but it's not a risk most people want to take. This means block prep by a knowledgeable shop and creates a significant barrier to most folks if they want a very reliable car. Most basic engine systems would still work at this stage, but you've modified much more than stage 1. Driveability should still be good, but you've modified the air metering and fuel delivery enough that performance and reliability are dependent on your tune. It's not enough to just have a maintained car at this stage. Not everyone can tune a fuel injected vehicle with precision. You'll notice a lot of threads pop up with folks having issues at this stage. It's more difficult to troubleshoot problems once you throw these modifications into the mix. Stock intercooler is likely a restriction and should be upgraded. Stock clutch isn't going to hold and even the better aftermarket full face clutches may not work. Many people run a 6 puck clutch at this point.

Stage 3: Standalone ECU. This represents essentially everything beyond stage 2. It sounds like you're in between 1 and 2 so I won't add much here.

I'd decide what power level and budget you want. I think trying to get to stage 2 (mainly defeating fuel cut) creates more headache and financing than a lot of people are prepared for. The forums are continually filled with people having issues with basic reliability in this area and I think a lot stems from folks not quite ready to jump into all that's needed to reliably run a 7M long term above fuel cut. Of course you can make it happen on a budget, but to me... if we're talking dollars and time... there's not much difference between 360whp and 500whp. If you're not ready to commit to the things required to get 500, you're probably not ready for 360.

Conversely, if you're ok with low 300's then it's a MUCH simpler equation and you can hit those numbers all day long with minimal expertise and minimal funding. Just get the motor running well (OEM head gasket, basic machine work, basic maintenance), throw on a big exhaust, boost controller and you're done. I've built my current mk3 with the top of Stage 1 in mind. If I was starting again today I'd aim for 500 and the top of Stage 2. Then again... I make good money as an engineer today and 8 years ago when i started my current mk3 build I was working retail part time...

 

[SeeUSmile]

If you wanna DIY give these a shot http://www.lislecorp.com/divisions/products/?product=43. Much better than the spring loaded stone glaze breakers. If you can't trust anyone but yourself, try giving it ago

 

[AcIdBuRn02ZTS]

Believe me... I WISH there was a competent machine shop in my area. The shops around here can't even get a small block chevy right... The shops around here are paying 10-12/hr so most of the guys that are there are just there for a paycheck...

I'm also very picky... if a shop is going to bore the block, they best have a torque plate... if they are going to deck the block/head... they should be able to tell the RA of their equipment... etc..etc...

My power goals are 350-400whp. As far as the bottom end goes, it'll be fine at those power levels and live a long healthy life if everything is in spec when it goes together. I know I'll have to get a piggy back system, injectors, etc... but thats down the road. Plans are to get it up and running good and work my way up.

Thanks for the input guys
-Chris

 

[AcIdBuRn02ZTS]

If you wanna DIY give these a shot http://www.lislecorp.com/divisions/products/?product=43. Much better than the spring loaded stone glaze breakers. If you can't trust anyone but yourself, try giving it ago

For some reason, the link didnt work... but I'm probably going to order a Lisle 15000. After doing some reading, guys have even used this specific hone to bore a cylinder and managed to keep it straight. Guy claimed to take .020" without any tapering (no I dont think thats a good idea.. lol). I'll probably order one in the next week or so just to keep in the tool box even if I end up needing to go a different direction.