Indy 4700 Engine questions

Hello fellow Maseratisti's

I am in the process (year two into it now) of restoring AM116*49*1838 an Indy4900 that was, most likely, delivered or re-engined very early in it's first two years in Modena with a 4700 engine. (no: 107/1*1538*) It might be the only 4.7 engined Indy in the world with Citroën brakes in combination with the 4900's fantastic Khamsin gearbox and the latest upgrades of the Indy series including the interior. It's not a typical, low milage "matching numbers" car, but to me, the small series of Indy's with LHM brakes and IMHO benefits of the 4700 engine note over the 4900 is enough for me to want to invest in a proper restoration of her, while I continue trying to dig up her past and finding out the story behind the 4700.

I was hoping that those with knowledge with restoring these engines, or that have had work done to their engines in the past could advice me a little. I have no previous knowledge with restoring the Tipo 107 engine from before, given that my previous car was a Merak3000. But I am very fortunate that I have a skilled engine restoration mechanic that will be supervising all the work this winter but he does not have indepth knowledge of this particular engine type.

As the engine project stands now, we will have to replace the pistons as well as the cylinder sleeves. The old pistons are the low compression kind (flat tops), I am thinking about replacing these with the high comp pistons offered by MiE. Are there any reasons for why I shouldn't do the change to high comp?

The rationale for changing the cylinder sleeves is that one sleeve has heavy scratching on the top. Another cylinder wall got a serious scratch running the entire height of the combustion chamber.

I am extatic over the fact that we decided to open the engine up this fall and inspect and finding these critical issues with the engine now rather than having it self destruct next spring.

I am thinking it makes sense to also change the valves, the 3 chains and tensioners, the main and rod bearings, the central timing gear shaft & the connecting rod bolts while the engine is out of the car.

Should I replace the old valve springs with MiE's reproduction springs?

Should I replace the crank shaft main sprocket regardless of level of wear of the old one?

Any other comments about what to look out for and inspect in this process is greatly appreciated!



Kind regards

Kim

 

Having rebuilt a number of these engine's i would opt for boring the liners and running the forged J+E pistons, changing the liners is time consuming and expensive. You will need a competent Machine shop, ( Good Luck) to do the work, Liners will need to be locked into place to bore them. You can call me if you get into problems.. Dan 760-363-7448 PST

 

Some good questions, first the cylinder hears are they the hemi type or bath tub type?
Makes a huge difference to the pistons you use.
Liners with the Khamsins I have seen done changing liners isn’t that big a deal. If the shop has done diesel liners then it’s not a problem. The engines head bolts not studs so milling the deck height of the liner isn’t an issue. But note the liners protrude the rest of the deck the hand book gives the measurement
Issue I have with JE pistons as good as they are the JE piston engines are noisy. If you do go the JE route make sure that the engine shop knows JEs run two and a half thou skirt clearance not four.
Hopefully you shouldnt need to touch the crank so leave the shrunk on sprocket on the crank alone unless its an earlier keyed on one.

I have sent a PM re Valve springs
Regards
Graeme

 

Thank you both for your answers. Slightly different point of views, but both are equally helpful.

Dan, I appreciate that you are saying that changing these liners isn't a walk in the park!
That's good information for me to consider, when we decide what route to take, if the liners are recoverable at all. I have confidence that the chief is able to do the sleeve swap if needed. He has experience on a multitude of different enginetypes.

au-yt, if the tops are hemi or bathtub type, I don't know (don't know the difference, I havent seen other than this kind) According to Stuart at MiE, my engine can only handle the flat JE pistons. Thank you for the headsup with JEs run two and a half thou skirt clearance not four.

So far two pistons came out with broken rings, the wear of the crank should definately be addressed, 2 maybe 3 cylinder sleeves are damaged.

I have added a few pictures of the the (rather sorry) state of affairs.

Kind regards

Kim
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Nice gesture Dan!

 

We have decided it is possible to to bore and hone the existing cylinder sleeves so that saves a ton of work

The valves are cleaning up well and are fine so they will be reused.

I am wondering if anyone here has a good idea of how to extract these gears on the pictures attached? Do I need to fabricate tools from patterns (that I don't have) or are there standard tools that are available off the shelf for these that we can use?


Kind regards

Kim
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

You will need to purchase the pullers from ( heartland products? I think that 's the name) They make pullers.

 

Thanks Dan!

kind regards

Kim

 

Different question, on my Indy, the dashboard seems to be lined with a reversed black hide showing the backside as an alcantara-look-a-like. I assume the previous "restorer" took what they had laying around for completing that job.

Does anyone know what type of fabric that was used on the Indy?

According to MiE they haven't seen any Indy4900 with mousehair type dashboards. They say black vinyl or leather was used. If anyone can steer me in the right direction it would be great, I'd like to restore her to original spec if possible.

Kind regards

Kim

 

The first thing you need to do is buy the QPort service manual from MIE or on line.. It gives you all the demensions and clearances you need for the engine rebuild. It also shows you a picture of the puller you need to remove the sprocket on the front of the engine as well as the information you will need to retime the engine. There is another puller made by Snapon that will work. THis sprocket is pressed on and takes a lot of force to remove. There is no keyway, just the press force keeps it from rotating.

 

Thank you eogorman!

I have the QPIII manual, i've seen the puller in the manual, do you have details on the puller from Snapon?

I have a toolmaker on hand if I am able to get the measures of the tools needed. Alternatively my mechanic will coordinate with the toolmaker on site to make the needed pullers. It is a bit up to him how quickly he wants it.


Kind regards

Kim

 

MIE is now selling a puller for the crank sprocket, too. I don't know how it compares with the others.

 

same as original. I use one multiple times as I own 24 V8's. no problems

 

good move would b to remove the liners. cut a second groove for another seal ring and install with new rings

 

I will step out there and say that it is the mouse hair or Alcantara on that late dash top.
Leather would have been unusual or by special order only.
As to the heads, you have the truncated type which is good as they ARE the higher compression heads. I would not change the pistons to a pop up type, I would use the original type high quality pistons.
Are you sure this is a 4.7 engine?
I would also recommend power honing the liners by using a torque plate to hold them in place, but no more than the first oversize recommended by the factory. The liners are thin.
Can you tell us aha the engine number is?
Does it have one zero or two zeros followed by a number?
The above is offered buffet style, i.e. take what you want.
Ciao,
FGM

 

What a great place this is, thank you all for the contributions.

GLB, I the crank socket puller from MiE is somewhat toppishly priced, so I was hoping to find an alternative to buying this with a one off cost of USD 357... I assume that Snapon & Heartland have these pullers once I find out the dimensions of them, it's not rocket or kryptonitish material, its a socket puller.

Bundas, I am not very familiar with what you are suggesting, can you elaborate a bit on what this would give of benefit other than a tighter seal on the pistons?

I do have to think cost at one point or the other, if these engines are capable of 100 000 km overhaul intervals as they stand, thats should be sufficient for my needs the next 25 years. Does it then make sense to pull the liners if the cost increases by a factor of two or tree over bore and honing them? I would like to hear your thoughts on this since I am at a crossroad where I can go either way with the engine restoration.

The present idea is to use the flat JE pistons from MiE and bore & hone the required 94.49mm (3.72")

Portenos, the engine number is single "0" - "3608" and the engine block number is 107/3MB67167 this corresponds to the engine of the Maserati Indy chassis # AM116*1578* which was a 4.7 litres according to Fabio Collina.

I have not yet been able to dig up any hard intelligence on the faith of Indy*1578*

Stroke lenght on it, is 85 millimeter, the current pistons in the engine are 93,84 millimeter. supporting that this is a 4700 ccm engine.

In regards to the mousehair question, thank you Portenos, I would think that the rationale from the previous uphosterer must have been to reproduce something close to what was present in the car given everything else is/looks original.

I have seen that Ivan Ruiz red 4900 (lhm) looks to be alcantara or mousehair http://www.ferrarichat.com/forum/maserati/379107-maserati-indy-4-9-a.html

same goes with the one Azul considered/bought? I will go another round with MiE too see if it is possible to ship over some fabric to redo my dash.

I like your buffet style FGM, I'll take it all aboard, thanks!


Kind regards

Kim
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Hi Kim,

If you find the Snap-On or Heartland part number for the puller, please post it. I checked Snap-On's tool catalog with no luck. Heartland definitely makes the right kind of puller, but so far I've found only motorcycle and APV parts. I'm hoping not to have to remove the crank sprocket on mine - it's coming apart mainly so I can paint the heads - but I too would like to find something cheaper than MIE's. As for a gear puller being a gear puller, weeelll, not so much. Internally and externally metric-threaded contraptions aren't thick on the shelves around here. I used a conventional gear separator to remove the distributor drive gear and chipped a tooth. It has no functional effect, but it's irritating and I might spend the $270 or so to replace it - the expensive gear puller doesn't look so bad in that light!

 

is on the bottom of the liner. extra precaution against leaking. several of my Indy's have 100,000 miles. oil burn seems the only issue. some power loss as well but I do not race them.

 

GLB, i'll post it if I manage to match up what they have vs what is needed.

Bundas, I see, so an extra protection on the outside of the bottom of the sleeve to separate better the oil and water side.

My Indy (86K km on odometer) had fuel in the oil, probably found it's way due to cracked piston rings and fuel excess in dead cylinders (with no spark due to glued hole/ cracks in the distributor cap) I have had no water in oil or oil in water issues on this engine. If the sleeves have been sitting for 40 + years and are snug fit and been stable, would you invest twice the labour cost of boring, honing and reinstalling everything into the engine to address it? or would you leave it as is, bore and hone the cyl's in less than half the time needed, and "risk" that since it hasn't happened in the last 40+ years it will most likely not happen in the next 25 years if I use the car for normal sensible driving, not overly stressing the engine? If People here saying that it's like russian rulette to not extract the cylindersleeves for this extra protection, well then I need to re-think the budget for this job.


Kind regards

Kim

 

seals rot

 

Reading through the Khamsin thread, there are some interesting solutions: http://www.ferrarichat.com/forum/maserati/187217-maserati-khamsin-135.html

 

Correction
No zero = 4.2, one zero = 4.7, two zeros =4.9.
This is for the wet sump V8 enngines only.
FGM

 

The converted puller looks like a good fit for the crank gear. So far I haven't been able to find a reference to the CK45 tool they started with, but not everything is on the web.

 

Bundas, I see your point with old is old. I'll discuss it with the Chief. He came back yday saying the sprocket was off the crank so I guess he made something from what he had laying around for this job.

Positive note of the day, the S-5-24-3 gearbox is decleared in good health, and will receive new bearings and gaskets prior to reinstallment.

Kind regards

Kim
Image Unavailable, Please Login

 

look very careful at second gear sycro. that is a weak point