My original duke engine had a knock in it so I picked up this other one pretty cheap. The guy said that the motor ran. I started tearing it apart and tested the compression in each cylinder. Found out that it leaks air from the intake valve, exhaust valve and the rings. Now I am going to check the motor that knocked and see if its heads are good. Two motors to make one.... .

So my question is; can I just replace the crank and bearings from one into the other? Or should I do it the right way and buy a crank kit. If so I found this one site http://www.precisionengine.com/crank-kits/ but have no clue which one I need.

Check around at your local parts houses, and or machine shops. I had one done 10/10 for a 4 cy ford tractor for 85.00 plus bearings.You might just be supprised. If you have a knock, often times the inserst wil " walk" or move inside the connecting rods. This will render the rod in need of repair also. Looks like the best repair is a full repair.
Joe Crawford
Texas

I havent had time to take the knocking engine apart but the one I bought looked pretty good on the inside. The crank shaft had very very slight grooves. I found oilpan sealant in the oil sucker thing and also found a tiny ring. It is probably a quarter of an inch in diameter and considering I found it in the block, that cant be good. I plan to take the blocks, shafts, bearings etc to a machine shop and have them tell me which ones look best to use and/or easiest to machine down....ie, cheapest

The knocking engine probably started because the motor was ran without oil. At least that is what it looks like. I found more of the rings in the knocking engine so does anyone know what these are....if they are important....maybe something from the factory?




More questions...
I have heard that an s-10 head can be used on the duke. Does it bolt right on or is there another head I can use. Since I have the whole block stripped I would like to get some upgrades to get a little more power from it. I will be getting the head and everything else touched up by a machine shop.

I am also planning on painting the block so I am wondering what classic block color would look best. The car will be red.

[This message has been edited by 84FieroVT (edited 06-21-2008).]

Those look like the rings on the valve cover gasket.

Red block and black on the covers might look nice and give your engine a custom look. I am going with an aluminiumized grey on the block and low gloss black on my covers. I also painted the engine bay in the same Dupli-Color 500*F low gloss engine enamel to give a nice coordinated look. I'm still in assembly mode, no pictures yet.

From what I have read, the 88 Duke head was an improved version from earlier years as it flows better, not sure about the S-10 head though.

quote Originally posted by 84FieroVT: The knocking engine probably started because the motor was ran without oil. At least that is what it looks like. I found more of the rings in the knocking engine so does anyone know what these are....if they are important....maybe something from the factory?

I do believe those are index shims. They are used so that you can point the spark at the exhaust valves for a little bit of free performance. This seems to work well with the 350s.

Unless my perspective is way off.

[This message has been edited by AP2k (edited 06-22-2008).]

quote Originally posted by AP2k: I do believe those are index shims. They are used so that you can point the spark at the exhaust valves for a little bit of free performance. This seems to work well with the 350s. Unless my perspective is way off.

I should have said where I found the rings. In the one I bought I found it in the oil pump stuck to the screen. In the knocking one they were sitting on top of the head. I dont know if that would make a difference to what you guys think they are.

quote Originally posted by 84FieroVT: I should have said where I found the rings. In the one I bought I found it in the oil pump stuck to the screen. In the knocking one they were sitting on top of the head. I dont know if that would make a difference to what you guys think they are.

Valve cover gasket o-rings, penny added for scale.



I'll snap some pictures of my engine later this week after I get the covers back on so you can judge for yourself on the looks of grey and black.

Make sure that any parts you disassemble remain together. Keep each crank and its' rods/pistons as a set, number each rod and cap from the bore they belong to. Do not mix up the lifters if they are flat tappets. They must go back in their original location.

Get a quote from a machine shop to grind the crank .010/.010 (or more if needed) and to re-size the rods (if the rod bearing spun)

As long as the ridge at the top of the cylinder isn't too bad you don't need new pistons

Northernautoparts.com sells ring kits for the 2.5 (perfect circle rings, sealed power bearings and felpro gaskets.) for about 120.00.

You'll probably need to rent or borrow a few tools to do a rebuild but it really isn't hard.

David

------------------
His Fiero: 1984 2M4 Coupe

Her Fiero: 1984 2M4 Convertible

Thanks for the picture, I can stop wondering what those rings are now.

This was my first motor rebuild so the lifters sort of fell out...my bad.....but I don't think it will matter by the end of this rebuild....

I brought my motor completely disassembled to the engine shop and they gave me an estimate of $900-$1000 for all parts and labor, that is with me reassembling it. It has to be bored out and ground down, valve job etc etc. So pretty much a new engine with new pumps new just about everything. I'm not sure if I want to spend that much on a this car. I have the money but I don't know if it is a good investment, I'm uncertain of the resale value once I'm done. Any thoughts?

I dont feel like making a new thread so I will post another question here:
Is there any way to tell if a transmission is good without opening it up?

bump

A few things to consider when choosing the block paint, any color has the benefit of better oil leak detection vs black.
But Black is timeless, it never looks cheesy, and doesn't look bad when you actually drive the car and it starts to get dirty.
Colors can also be so attractive they can take away from things, I'm going black because I don't want my paint to be overly bright,
taking attention away from my SD4 valve cover and Edelbrock Victor 4C intake.

Having a colored block also makes me feel obligated to put a finish on the trans, were as the black being neutral looks more natural.
personally I stay away from silvers and grays because they look like crap in the presence of any polished aluminum.

Check out POR-15 products Engine Block Paint, its available in an array of GM factory matched colors, but it's a little expensive.

Also talk to some old-school builders about what can be painted inside. Were and with what? I know people have been paining
oil lifter valleys and other key areas for better faster oil return. This is a very affordable way to higher performing lubrication system.