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Lycoming 8-98 Parts Sources


Curt Curtiss

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Not sure if this is the correct place to post or not, if not let me know.

 

I am looking for recommendations and guidance on Lycoming 8-98 Engine parts sources.

I have located replacements for the timing chain, valves, and guides but This is what I still need:

Pistions - I am aware of Egge, are there any others?

Rods/Insert Bearing part number - My rods are Babbitt but I want to convert to inserts. Does anyone have insert part numbers so we can get a machine shop to modify the rods, I have heard some "Alison something ???" bearings might be the ones? Are there any sources to buy rods that are already set up for inserts?

Valve Springs - I want to replace the valve springs, any sources or replacement part numbers for replacement valve springs?

Main Bearings - I would like to convert the mains to inserts, I know there are some modifications that will need to be done and have hear about modifying some Chrysler rod bearings to be mains but still have not found part numbers others have used, a part number would be helpful.

CAM Bearings - Is there a new cam bearing that is available or are you all just reusing the existing if they look ok?

I know this is a lot but any help is appreciated.

Curt

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Re the bearings, the advice I have seen on these fora is to take yourself and your bearing sizes to a friendly engine reconditioner and read his or her book of bearings listed by size. Such books are not easy to find apparently. There have been pistons listed by size on these fora - perhaps on JV Puleo's topic on his 1910 Mitchell.

 

If your engine is out of a car, is there a forum below that is dedicated to that car? You may get more traction by posting there as well. Go to Forum Home and scroll down to see what you find.

 

Oh, you're in a fairly small pool of owners. It might be useful to post the sizes; someone may have a cross-over for that size not listed for Lycoming.

Edited by Spinneyhill (see edit history)
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I agree with Spinneyhill. 

 

I have an engine shop in Ohio that specializes in antique motors and does my old motor machine work.  He is very good at finding modern pistons for antique vehicles for a fraction of the price of having pistons made by doing a size comparison search.  For all you know, pistons from a 1970 Ford Pinto might work fine. No insult, but never know. Modern part at a good price.  Besides diameter, also need to know wrist pin height to top of piston, pin diameter, etc.

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On 12/20/2017 at 11:38 AM, Curt Curtiss said:

Not sure if this is the correct place to post or not, if not let me know.

 

I am looking for recommendations and guidance on Lycoming 8-98 Engine parts sources.

I have located replacements for the timing chain, valves, and guides but This is what I still need:

Pistions - I am aware of Egge, are there any others?

Rods/Insert Bearing part number - My rods are Babbitt but I want to convert to inserts. Does anyone have insert part numbers so we can get a machine shop to modify the rods, I have heard some "Alison something ???" bearings might be the ones? Are there any sources to buy rods that are already set up for inserts?

Valve Springs - I want to replace the valve springs, any sources or replacement part numbers for replacement valve springs?

Main Bearings - I would like to convert the mains to inserts, I know there are some modifications that will need to be done and have hear about modifying some Chrysler rod bearings to be mains but still have not found part numbers others have used, a part number would be helpful.

CAM Bearings - Is there a new cam bearing that is available or are you all just reusing the existing if they look ok?

I know this is a lot but any help is appreciated.

Curt

 

A lot of what is sold is cheap junk made from inferior materials and has a poor finish. Aries or Ross for pistons, no questions asked, I won’t mention others, but more make junk than you would think. Most of the valves sold today are cheap Chinese blanks that are soft, and quaility is poor. Be sure to use a Rockwell hardness test, and you will be shocked at the stuff that’s being sold. Your engine is neither common or incredibly rare, but that being said, it isn’t an easy or inexpensive one either. Bearings are straight forward if you use good people.........read this ten times over..........most shops today have no clue on how to do your engine.......now go back and read it again. Your motor on the cheap side will run 20 to 25 grand.......,any less and it won’t hold togeather. Parts, gaskets, paint, machine work, all are very time consuming and expensive. Add in the carb, Generator, starter, distributor, water pump, fuel pump.........there is a lot of parts in that engine. Any rebuild should include a break in on a dyno, read that ten times over also. If your builder doesn’t do the entire engine and run it befor sending it to you, they are all about short cuts. If you farm out all the work, no one will ever warranty it.......they will just point fingers at the others. We use modern ring packages on our builds, less drag and better sealing. Be sure to check for cracks in the block, head, and manifolds. Post a few photos. Why are you building the engine in the first place? Most likely it’s been done in the past and has few miles on it. Guess why........not trying to be negative, just go into this with open eyes. There are good builders out there, and they are VERY busy. Anyone who says they can get it in and out in less than six months.......just run away. Post a few photos please. Show any issues or current problems. Ed

Edited by edinmass (see edit history)
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PS.....spent the day installing a new head on our 851 SC speedster today. It has been fairly straight forward so far. With a bit of luck I’ll have it done early next week. 

 

I noticed you 31 looked very nice in the photos.......as did the engine. Don’t be in a hurry to go to inserts, most shops are NOT qualified to do the work. Many rods can not be converted, but I am not familiar with your particular application. Good babbit is FINE......... and is much less expensive than converting to inserts in most cases.  

Edited by edinmass (see edit history)
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If you're still looking for parts you might try a new post including the Lycoming ID (supposedly their GU) in the title...

Lots of big and/or powerful cars were cut up in the depression years simply because too few people could afford to maintain/feed them, the engines farmed out to all kinds of work. I think one of these Lycoming threads mentioned an 8 found in a sawmill or some such...

Should you have a GU, a 36 replacement parts catalog says it shares piston assemblies  with the GC and GUC 8s and the WSG and WTG 6s...two piston ass'blys are listed: Nelson Bohnalite and Gray Iron, both "original type". I don't know if that means the factory offered the choice or if the parts company was offering it.

There was a valve change--shared with WTG, WSG 6s to #75381, only with GC, GUC after...(same source)

There was a bearing change--shared with GR after #GR21691 for GU to GU35453, shared with GC for GUC after GU35453... (same source). If looking for NOS/NORS parts might help to note the other engines... Good luck!OOPS---should've proofed---should've said bearings shared with GC, GUC for GU after GU35453

Edited by Bud Tierney
Correction in beaRINGS (see edit history)
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