Turbo Install on a worn out engine? In need of advice.

[86deezel]

So i've got an 86 6.9 idi. I would love to throw a turbo on it. looking at the banks sidewinder kit to be specific. My question is, My motor has 285k on it, and seems to me like it has quite a bit of blowby. Would i be seriously shortening the life of my engine by adding the banks kit? It runs flawlessly and seems like it makes good power for a n/a idi. the blowby is all that i am worried about.

Thanks in advance for the help!

 

[79jasper]

At that mileage, I would be more worried about cavitation or the headgaskets popping.

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[icanfixall]

Welcome to the forum...
Not a problem with cavitation because its a 6.9. Head gaskets may become an issue. blowby is probably from old worn out valve guides and seals. Might be advisable to give it a valve job and stud the heads with ARP kit. Usually the bottom end is rock solid and not needing anything. Doing a compression test will tell you what the rings are doing. Just depends on what you want to do from nothing to a complete rebuild. A turbo will take away some of the life left in the engine but to say how much depends of how close the engine is to a rebuild and how you will drive it after the turbo.

 

[jaluhn83]

Depends - what do you do with it? How much of a problem will it be if you blow it up?

Hard to really tell what the risks are - the turbo is definitely going to put more stress on it, so if something is worn and just about to let go it might very well be the straw that breaks the camel's back... on the other hand, if it's that close to letting go it's just a matter of time anyway. Or it might be fine for another 100k... who knows.

Personally, I'd probably say go for it, but maybe try to not hammer it too hard... I'd also be saving/thinking about doing major motor work before too long turbo or no turbo.

This is conditional on a dead truck not causing you too much trouble - if the truck blowing up means you can't work or something then I wouldn't risk it.

 

[riotwarrior]

Welcome to forum, take a look in the tech, and FAQ sections, also the hall of shame.

IMHO that engine if there is that much blow by should be checked with compression tester before an install of turbo.

If you've got good comp across all cylinders, then ya maybe some ring issues and some Auto-RX may be your friend!

Dig around for threads on Auto RX and do that recheck compression once you've cycled through a couple times and see if it picks up and blow by decreases. If so, then by all means add turbo.

On the other hand if you have low comp and such I'm thinking it's not a good idea to bother and just go with whatcha got.

Just my thoughts observations on these trucks..

Al

Again welcome to OB

 

[jaluhn83]

Now that you mentioned it, low compression might actually help a bit with the turbo - lower compression pressures. Same effect as shaving pistons.

 

[chris142]

Whats the chances of the engine gernading and filling your new turbo with metal shavings?

 

[Bashby]

Whats the chances of the engine gernading and filling your new turbo with metal shavings?

I think the chance is pretty slim.

Welcome to the forum...
Not a problem with cavitation because its a 6.9. Head gaskets may become an issue. blowby is probably from old worn out valve guides and seals. Might be advisable to give it a valve job and stud the heads with ARP kit. Usually the bottom end is rock solid and not needing anything. Doing a compression test will tell you what the rings are doing. Just depends on what you want to do from nothing to a complete rebuild. A turbo will take away some of the life left in the engine but to say how much depends of how close the engine is to a rebuild and how you will drive it after the turbo.

How can the blowby be from valve guides or seals?

 

[79jasper]

I think the chance is pretty slim.


How can the blowby be from valve guides or seals?

Because the explosion can push back up through the head into the valve covers.

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[icanfixall]

Blowby can very eaily be from worn out valve guides. See Riotwarriors writeup of loosing a valve that cracked a cylinder and ruined an engine. When he puled the valve cover on the bad cylinder there was a bunch of crap from blowby all over the head and springs. That valve that broke was the reason.

 

[PackRat239]

You would have to have bad valve to seat sealing long before you could have blow by from valve guides and never from seals. There is no pressure in the valve pocket.

 

[PwrSmoke]

I think the advice on pulling the heads and studding it is best.

My '86 has had a turbo on it (Banks Gen 1) since '87 and 7K miles. In 2010 I blew a head gasket and had occasion to tear into the engine. I saw the effects of turbocharging an NA engine and them working the engine hard over many years. I hate to think of how stretched and weak the head bolts and gaskets would hold up on a 285K engine if you weren't very careful. Head gaskets and studs first and foremost! I saw signs of fretting and long term leakage on the head and block gasket facings telling me I had lifted the heads on more than one occasion. Well, that is no longer an issue with the studs and freshly redone heads. The valves were really in bad shape considering. The bores, pistons and bearings held up well but my engine has a lot less than 285K on it. If it were me, I would budget the money to pull the heads and get them redone. Evaluate the bores while you are in there and the block deck. Install head studs, the reworked heads and the turbo kit while you are reassembling the engine (it will be easier that way... it's not particularly easy to install). You'll end up with a better result.

Or, you can install the kit onto the engine and hope for the best. If the engine is in good shape and you don't wail on it, nor turn the fuel way up, you "should" be OK for some period of time. Bear in mind that the turbo will uncover and magnify whatever weaknesses there are in an old, tired engine. All you can do is hope those weaknesses are minor and easily fixed. First and foremost, go easy on the fuel settings. Adding more air in itself is not the problem so much as the extra fuel you put in with it. Banks had two fuel settings and on the low (emissions) one, it really made the truck less smokey and EGTs were actually lower than stock under the same load conditions because of the cooling effect of the air. Didn't make as much power as on the high setting but it wasn't as ******* the engine and nowhere near as smokey.

 

[riotwarrior]

You would have to have bad valve to seat sealing long before you could have blow by from valve guides and never from seals. There is no pressure in the valve pocket.

NOT if it's an EXHAUST valve guide worn out...THEN exhaust gas can and will get past the guide..go ahead...ask how I KNOW!

On an intake valve yes, it would have to be a bad seat and guide to do this so under compression the gasses escape past valve and up guide and into intake...

I don't see this being a problem on an intake side as much as exhaust however if there is a chuff heard in the intake it's clearly NOT sealing and some compression is getting past that valve/s

Just sayin....

 

[86deezel]

Basically I want the turbo for a little more oomf and better towing performance. I don't plan pump mods or ragging on it. So it sounds like head studs are a good idea and compression testing to see what my compression is like. Anything else? Thanks so much.

 

[86deezel]

Also, what's the correct procedure for compression testing these engines? Just unhook the fuel shutoff or?