Titanium rods ?

It does help...to scare me about the 355 stuff I'm planing to use

Now I wonder what's different???

Does anybody have the specs for the 360 rods and bearings?

Here's the specs Scott already posted the the 355 on others in the other thread:

here's what I have;
308/328
CC = 136.913mm~137mm
pin bore = 21.5mm~21.521mm
crank = 47.129mm~47.142mm

348
CC = 136.913mm~137mm
pin bore = 21.5mm~21.521mm
crank = 47.129mm~47.142mm

355
CC = 136.975mm~137.025mm
pin bore = 22.990mm~23.010mm
crank = 47.129mm~47.142mm

width are all the same at 20.85~20.9mm
weight for steel 520gr~600gr
weight for Ti 380gr~408gr

308/328/348
OD = 21.535mm~21.548mm
ID = 18.515mm~18.535mm

355
OD = 23.050mm~23.09mm
ID = 20.015mm~20.025mm

here's something else though, the big end has the same OD and ID on the crank but the bearing changes with the Ti rod, to a thickness of 1.712~1.721mm vs 1.714~1.723mm on the 308~348.

 

Mark, just a thought for you to ponder. In all of my research on the 355CH cars I never had heard of rod or bearing failure, I think if there was even one I would had found something about it. Most of those cars were pushed hard and when they were refreshed it didn't include rod replacement that I was ever aware of just rings and bearings. I am mentioning this because of the great test bed the challenge races would have been on components of the 355. Again just a thought.

 

Mark, I looked up the numbers for the early 355 rod and main bearings compared to the later cars( '98 to end) and they are different.
You also mentioned steel rods for the 355, I thought all the 355s came with Ti rods, where did you find the info on the steel rods? I found the same part number for all the years on the rods.

 

The bearing thickness if converted to standard measurements (mostly what I use) equates to only .0001" of an inch in extra oil clearance (1.712 x .0394 = .0674", 1.714 x .0394= .0675". One tenth of a thousands is nothing to get excited about as far as oil clearance is concerned. But maybe Ferrari thought that would help, as I know that there were quite a few rod bearing problems on 348's, but haven't seen an problems on 355's. I did have one 355 with a rod bearing that was on the verge of spinning, but I believe that was from being in a cylinder that was probably detonating from other problems. I'm not sure, but I bet the bearing length would be the biggest difference between the engines to provide more bearing "crush" when torqued in the rod bore on ti rod vs. steel rod engines Just a guess. I don't know if you could ever find a spec anywhere for bearing length though.

 

Vern,
I know of 1 355CH that spun a rod bearing, a freind was considering pruchasing it last year. Your point is taken though, there is probably nothing to be concerned about.....although when part numbers change mid model I always wonder why, but it could be for any number of reasons that have nothing to due with any performance problem.

 

Vern,
Thank you for the heads up on the part number change! Now I need to find out what year car my first 6 rods are out of so I can get the right bearings and a second 6 to match.

I know of no steel rod 355s....steel rods are what I have in the 400i block I'm using and I was considering having a new set of better aftermarket steel rods made before I decided to fit the 355 Ti rods.

 

Your probably right that the answers on bearing changes will forever remain a mystery....like a lot of stuff ferrari does

 

So the 6 rods I have are out of a '98 model year car with a december '97 build date.....I wonder which part number they are........

 

I see all connecting rod bearings the same from 2.7(95) thru 5.2(99) original sizing....the only difference I am seeing is the rod end bushing(at piston pin) as being different between the 2.7 and 5.2 engines.

Vern am I missing a parts update or service update for my workshop manuals??

 

Sorry, I am just looking at PN's which does not give me material or size for this bushing.

 

My thoughts also, always makes me wonder why. Maybe as minor as changing suppliers who knows.

 

I have 2 additions to the 355 parts manual 1 in June of '95 and 1 in Nov. '97. The '95 book shows different numbers than the '97 version for the main bearings and thrust bearings.The connecting rod bearings are the same scenario. Piston pin(small end) bearing is also different between the books. A lot of the time the books will tell you exactly when the change occurs, by engine # chassis # etc. but not in this case so who knows when the change occurred other than all '98 and '99 cars would have the different bearings. Hope that helps

 

Not sure I understand about the "right bearings" the only bearing available is the 2nd/newer #. With the 355 rod being the same part #for all years the 2nd bearing will work in the earlier rod. My 355ch is a '97 body but all CH cars had '95 blocks and engine management CUs. My rod bearings were replaced with the 2nd number in 2000 when the engine was refreshed before I acquired the car, also my car was built prior(about a year) to the printing of the 2nd parts book update(with the new bearing #) so probably had the first series bearings in it originally. Just more thoughts for ya!

 

Oh, I mis understood your your other post, I thought the rods had 2 part number as well.

 

Sorry, I was saying that the 360 rod and the 355 rod #s were different.

 

Here's a question then, do you have any idea what is different? They sure look the same. I read something about the wrist pin bush size maybe??? I think I should have some of each here to compare in a week but it would be nice to know up front.

 

The later 355 rod wrist pin bush is the same part # as the 360. I never have found out what the difference in the 2 versions of the 355 rods are but you could be right about the size of the bushing maybe that end of the rod is bigger.

 

I got the first 6 of my rods today. A couple have a bit of corrosion under the bearing just like I was told to look for and a couple have some slight gaulling in the cap bolt holes. I think they'll be just fine once they're cleaned up but these are exactly the problems with used Ti rods....they just ain't as forgiving as steel and very careful inspection is required before re-use.

I think I'm going to machine the top and bottom on all the bolts so I can mearsure the stretch after torquing to be certain they are tightening properly. It's good practice anyway, but I'm now thinking it's required practice with Ti rods.

 

Hey Mark is it possible to take photos of the those issues I would like to see what they look like just curious.

 

I tried...but it's not very clear

I couldn't get the galling in the hole, but here's a pic of one of the bolts that has Ti basically welded to it on the body just above the threads. It's enough to cause the bolt to bind badly in the rod and severely mess up the tightening torque.

The second picture sure the corrosion. It’s small areas of pitting basically, easily deep enough to catch a finger nail in.
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The hole are through holes. The problem is in the holes. I'll probably get a carbide reamer to knock off any high spots then maybe a quick polish.

 

Thanks Mark for taking the time to post the pics interesting how that happens. Always had the mental picture that Ti was indestructible. I have quit a bit of Ti bits and pieces on my MV Agusta amazing how light it is.