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914World.com _ 914World Garage _ pulled the heads

Posted by: mcbain77 Mar 4 2006, 10:56 AM

So i pulled the cylinder heads off a 1970 1.7L engine and they look really pretty . . .

This is my first Type IV to dismantle so does anyone have any suggestions? How does it look? I also took off the oil filler assembly and found 1/2" of rusted out gunk on the area below the breather assembly. How do i clean this out? Should I crack the case and just start from the beginning?

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Posted by: mcbain77 Mar 4 2006, 10:57 AM

Area below the breather . . .

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Posted by: Headrage Mar 4 2006, 10:57 AM

Doesn't look so bad.

Posted by: mcbain77 Mar 4 2006, 10:59 AM

The top of the pistons look just about as good. Any suggestions on removing the carbon?

Posted by: r_towle Mar 4 2006, 11:52 AM

Easy off oven cleaner...works awesome.

Rich

Posted by: anthony Mar 4 2006, 11:54 AM

Why did you take the heads off?

Posted by: mcbain77 Mar 4 2006, 01:13 PM

Fake answer = the rocker assembly has some nasty corrosion and there was crap all over the inside of the head. I also pressure washed the engine and wanted to make sure i got the thing dry.

Real answer = DWD

Posted by: mcbain77 Mar 4 2006, 01:16 PM

What about the gunk in the area below the breather assembly? The oil filler corroded and there is a significant amount of deposit. I am betting there are deposits all throughout the crankcase because of this. Can this be flushed out?

Posted by: mcbain77 Mar 4 2006, 01:29 PM

Also . . . . broken fin

so new cylinder is needed right?

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Posted by: Andyrew Mar 4 2006, 01:37 PM

If the fin was a regular one.. I would say you could us it..

but that fin is needed to hold the cylander... Thats a toughie!!

Its only a 1.7, so you should be able to find a new cylander cheap..

Posted by: Headrage Mar 4 2006, 01:39 PM

You can run it with that fin broken. The head actually cinches the barrel down and doesn't come in contact with it.

Posted by: mcbain77 Mar 4 2006, 01:40 PM

Only a 1.7??????? I'll have you know that thing can crank out a mean 80HP at the wheels on a good day when the stars are aligned!

Posted by: fiid Mar 4 2006, 01:40 PM

I had a fin like that on my 1.7 and was told to leave it - it's only a small peice missing the heat dissipation won't change much.

I think (contrary to what Andyrew said) that the fin isn't actually the mating surface so I think you'll be okay. IIRC my 1.7 had exactly the same thing.

Posted by: mcbain77 Mar 4 2006, 01:49 PM

I'll probably leave it then. If the engine blows then it is only a 1.7 anyway.

As for the gunk below the oil breather, has anyone seen any corrosion like this? It is just sediment so I can clean it out the top. However, I was thinking that stuff like that floating around in the case is a recipe for disater. Even more so than a broken fin.

Can you flush a case? Maybe with consecutive oil changes after short running periods? Hmmm.

Posted by: Headrage Mar 4 2006, 01:53 PM

QUOTE (mcbain77 @ Mar 4 2006, 11:49 AM)
Maybe with consecutive oil changes after short running periods? Hmmm.

That's what I would do.

Posted by: Joe Ricard Mar 4 2006, 04:06 PM

My resolution isn't very good on this computer. Is that piston Domed or dished.
Domed is 80 HP early "W" case
Dished I don't think it makes enough power to pull it's self out of a wet paper bag. ON A GOOD DAY.

Posted by: mcbain77 Mar 4 2006, 06:29 PM

Dished. And now served.

Posted by: Bleyseng Mar 4 2006, 07:10 PM

dished so you are in busland a whooping 67hp.....change them out to a set of domed 90mm's.

Posted by: Headrage Mar 4 2006, 07:11 PM

QUOTE (Bleyseng @ Mar 4 2006, 05:10 PM)
dished so you are in busland a whooping 67hp.....change them out to a set of domed 90mm's.

Posted by: McMark Mar 4 2006, 07:46 PM

QUOTE (Andyrew @ Mar 4 2006, 11:37 AM)
but that fin is needed to hold the cylander...

The fins are only for cooling. The cylinder mates of the head at the cylinder wall only. In fact, if your fins are hitting the head, it can cause sealing problems.

Posted by: mcbain77 Mar 4 2006, 07:52 PM

I have never replaced pistons / cylinders in an engine before. Will this require any additional work like machining, etc? Will the ones from pelican parts work? Doesn't sound like too bad a price for a 20% increase in power.

Posted by: Headrage Mar 4 2006, 07:55 PM

It's a 1.7 so I can't offer any advice as far as increasing the compression/HP.

I'm just gonna give you a bump for the other guys....

Posted by: mcbain77 Mar 4 2006, 07:56 PM

In case it wasn't already painfully obvious, I am a complete novice and learning as I go along. My dad had this thing rebuilt in 1986 and the more stuff I find the more I think they did a terrible job. Stupid stuff like putting a 2.0L injector in with the other 3 1.7Ls.

As for the guy who asked me why I pulled the heads - now this is the reason!

It's only money.

Posted by: McMark Mar 4 2006, 07:58 PM

What are your plans for induction? Carbs, stock FI, aftermarket FI?

Posted by: mcbain77 Mar 4 2006, 08:02 PM

Stock Djet if possible. The FI portion is really in decent shape from what I have tested so far. From what I have read so far, I don't think I would switch to carbs on the 4cyl. Plus i don't want to buy another cam.

Posted by: McMark Mar 4 2006, 08:31 PM

You should buy a cam anyway. The one in there is wiped.

http://www.aircooledtechnology.com/store/product.php?productid=16171&cat=275&page=1 - $329
Cam - $180
Lifters $155
Balance rotating assembly - $120
I'd go with carbs on a cheapie motor - $400

All of the above is $1184.

Then put as much money as you can into heads. You could throw a set of new guides in there and run it. But you're risking everything you spent on the possibility of a dropped seat.

You'd have a sweet little 1911 motor. What's your budget?

Posted by: Bleyseng Mar 4 2006, 08:46 PM

The 96mm pistons and cylinders are a good deal
so the cam and lifter change is important cuz most cams suffer from lots of wear
Got to figure in some new bearings and seals
just have the heads bead blasted and have the guides checked for wear and excessive play and the heads bored out to fit the 96mm cylinders.

A 1911 with djet and a raby cam will get you to about 90hp and rev. Set the compression ratio to 8to1 and go!

Posted by: Tobra Mar 4 2006, 09:16 PM

I happen to have a set of stock 2 liter cylinders and pistons, was a throw in with some other stuff, though I figure to probably keep them. Could you make those work with the 1.7 head? I don't see why you couldn't, but I am not knowledgeable in such matters.

Posted by: mcbain77 Mar 4 2006, 09:18 PM

how much does boring out the head usually run and will i need to replace the guides and valves? Do you see any problems running the stock cam and lifters for a while and changing them out at a later date? Too many questions.

Also, will the stock Djet support the system or are carbs really recommended?

Posted by: mcbain77 Mar 4 2006, 10:45 PM

BUMP

Posted by: McMark Mar 5 2006, 12:56 AM

QUOTE (Tobra @ Mar 4 2006, 07:16 PM)
I happen to have a set of stock 2 liter cylinders and pistons, was a throw in with some other stuff, though I figure to probably keep them. Could you make those work with the 1.7 head? I don't see why you couldn't, but I am not knowledgeable in such matters.

NO! The pin height is different. Stock 2.0 P&C on stock 1.7/1.8 crank/rods is bad.

Posted by: McMark Mar 5 2006, 01:02 AM

QUOTE (mcbain77 @ Mar 4 2006, 07:18 PM)
how much does boring out the head usually run and will i need to replace the guides and valves? Do you see any problems running the stock cam and lifters for a while and changing them out at a later date? Too many questions.

Also, will the stock Djet support the system or are carbs really recommended?

D-Jet = sucky cam = sucky power.

Carbs = wild cam = fun power.

Choose.

While the engine is apart, you have the opportunity to change the cam pretty easily. If you want to build a tight budget motor, leave them in. If you want to splurge a little (~$300) you can really make it come alive with a cam swap. It all depends on what you're really trying to do here.

I would replace guides while you have everything apart. It's not expensive. Valves and seats can usually be reground.

Posted by: Bleyseng Mar 5 2006, 09:18 AM

DJET+ RABY 9950 cam= awesome hp

(Ihatecarbs)

Posted by: mcbain77 Mar 5 2006, 09:43 AM

I really want to keep the current FI so I might look at the Raby cam. Before i do any of this i need to confirm that I really have the 1.7L bus pistons. Check out the pic below. It is dished.

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Posted by: Bleyseng Mar 5 2006, 11:08 AM

Looks like it to me.........

Posted by: Jake Raby Mar 5 2006, 11:11 AM

Bump it up to a 1911.......