1500 or 1600 new build

Agnelli

Agnelli

True Classic
Teardown underway. First challenge uninstalling seized head. Extractor tool worked well.
seized head extraction tool.jpg

Head looked good once off
head combustion chambers.jpg

Did not appear to have had a head gasket failure way back when taken out of service
head off.jpg

crank.jpg

Rod bearings, cylinder walls, pistons all looked good. Cylinders dropped out with some taps from the crank side.

Plan next to hone the cylinders. Can either install factory 1600 Fiat crank and Kolbens (10.5:1), or stay with existing stock 1500 crank and stock European small flycut pistons (9+:1)
 
interesting..do you plan to have some head job\modification done ? rotating parts (crankshaft\flywheel\clutch) balancing?
 
One thing I now check on cranks is the flange that the thrust bearings rub against. Having dealt with dropping bearings last summer I'm now rather sensitive to this. Piston tops look pretty good.
 
I agree completely with Carl on the flange meeting the thrust washers after dealing with the same thing. You probaly already know this too and I'm no expert but I'd have the bores checked by a shop to be sure that they are completely true as well. Especially if you plan to simply hone them and install the euro 1500's. Ours were out just enough to need an overbore but originally planned to do the same as you with 86.4's. Decided withto go with 87mm. Anyhow,u just a thought
 
Feedback from all three of you much appreciated. I just got off the phone with Matt @ MWB, as luck would have it he just this moment restocked the 1500 carb gasket kit, which I promptly ordered. To your posts (1) yes to mods. Machine shop already has the 10 bolt Euro head sourced from a forum member in the UK. It is being pressure tested and evaluated for being true, and looking at the guides. 39.5 intake 33.5 exhaust valves on the way from Stole's, I am hoping if the head is good and Star Machine can mount and cut new seats. Not going to port, but might subject to your input. Euro cam + 40 dcnf on vintage Alquati. I will ask the machinist about balancing the rotating assembly. (2) Which crank and which pistons is subject to what I learn when I pull the original crank. I think the bottom end is original, but need to verify measurements. The Fiat 1600 crank is in storage at my friend's shop, which may be temporarily inaccessible due to world events and county shelter in place mandates starting tonight at midnight. So I might build with the 1500 crank and Euro pistons. Probably best to wait until I can have the machine shop properly hone the block (vs. honing in the garage), measure the bores, and go the whole way to 1600. Great advice about the thrust bearings and crank surfaces, I did read the threads about the adventures you've had. Will report back.
 
Someone here should be able to answer this question I'm sure but if you decide not to port after adding going to the trouble of larger valves and seats will their increased size actually be of any benefit? Just asking because if the choice of leaving the ports as they are and adding larger valves keeps the velocity nice and high increases torque then I may go this route? Not having a flow bench and not wanting to risk messing up the ports by hogging too much out decreasing velocity sounds appealing. Thoughts? Advice?
 
Thanks Paul. I've read the whole book that Steve posted and won't argue with you with regards to Steves knowledge on these engines. I'm still skeptical about putting a sanding cone in the ports, well with the exception of simply cleaning up imperfections? Too easy to completely screw up an entire head and intake from hogging out too much and losing all your velocity. He explained to me all the implications of thinning too much material using the 39.5 valves.
 
Progress: Dropped the torn down short block to the machine shop (n the back of the 128 Wagon :D). The machinist said the bores were "pretty rough". They definitely were super carbon glazed. We'll see if cleaning and honing get us to a placed where I can use stock diameter pistons. If not, will need to acquire 87mm high compression. The first Euro head is now cleaned, but has some water damage in combustion chamber #1. Fixable, but since I have another clean head in stock, we'll start with that for the oversize valves which arrived from Stole's race shop. Also dropped off the cam box with tappets intact and Euro cam, the original pistons/rods/bearings, and a full MWB premium gasket kit (which has the crank seals). I will post again once the machinist reports on the block condition and next steps.
 
Machinist called today having measured the valve guide bores in the Euro head. 14mm. Ordered 14.07mm x 42mm long. 8mm ID bronze valve guides from MWB. Next will be the measurements for the cylinders to ascertain hone vs. bore, and measuring the original crank and bearings. Results will guide (a) flat top small flycut Euro 86.4 pistons (b) flat top small flycut Mondial 87.0 pistons (just arrived from Greece): CH 34.45mm Total height 73.95mm or (c) 1600 stroker crank with Kolbens 86.4. Stole's valves measure - Inlet valve 39,6x8x108,5mm Exhaust valve 33,5x8x109mm.
 
Dr.Jeff said:
I'm curious what the damage is to the head? Do you mean erosion into the aluminum, or water leaking (i.e. cracks), or?
Click to expand...
Erosion in to the aluminum. Not sure how it had occurred. Machinist said it's repairable, with welding. Another approach might be for someone wanting to modify the combustion chamber, big valves, and mill. If that the case, then the damage may not be such an issue vs. keeping it stock.
 
Agnelli said:
will bore to 87mm and install Mondials
Click to expand...
I agree, if you intend to use new pistons anyway, then you might as well bore the cylinders to make everything fit perfectly.

Great price on those pistons. I don't suppose they are forged by any chance?
 
Visited the machinist again yesterday afternoon. Dropped off bronze valve guides and Mondial pistons. I do not believe they are forged, appear similar to factory Euro small flycut, and weren't priced as though forged.

While there measured the crank. For a high mileage engine the bottom ends are impressively durable. The crank will receive a polish only, no need to turn down.

Just ordered new OE NOS standard main bearings, standard dimension crank bearings, and high quality valve seals. Next step will be boring the block, reassembly of the short block, then oversize valve seats and head build.

The stroker crank will be held in reserve for either (1) 1500 block currently in my orange X or (2) 1300 block currently in the blue 128 wagon.
 
I'm in the (slow) process of rebuilding a couple of X engines. I found the same as @Agnelli with the crank and rods; not a lot of wear or damage so I'll just polish the journals and install new bearings. My cylinders also have a fair amount of glaze. But I'm keeping these engines stock and simple so I'll reuse the original pistons (also in great shape) and just hone the cylinders with new rings. Based on the current measurements they will likely be on the maximum end of the tolerance specs, but I'm opting not to replace the pistons so no need to rebore the cylinders. It would be different if I wanted to up the compression with different pistons, then I would definitely go oversized to get a perfect bore. We'll see how it goes.

Regarding the head, big valves, porting, etc, I'm with Paul and Cliff and follow Steve C's experience (just my opinion). According to how I interpret his write up, the biggest single advantage is gained from opening up the throat diameter a bit at the inlet valve seats. He says even a small increase there, with the stock size valves, will offer very close to that of bigger valves. And he says there isn't much to be gained from porting aside from the bowl area (which gets very involved due to the guides and overall location). So if you are going to install bigger valves and new guides then I think it is worth doing some porting (IF the person doing it knows what they are doing and has a flowbench). In other words at that point you should commit to doing everything for a maximum benefit. Otherwise it doesn't seem to be worth the risk of screwing things up (like @CnC79X19 said, messing with velocity) or only going part way with it. For me that means the alternative is to keep the head relatively stock (as far as the valves, ports, etc are concerned), and only do some basic clean up (these castings are very crude from the factory). Part of that clean up would include matching the bowl throats with the seats - they tend to be way off on these heads - in the same manner that I would match the ports between the manifold and head. In the process of doing that I also opened up the intake throats a little as Steve describes. But you need to watch the size/width of the contact area between the valves and seat; as you open the throat you also decrease that surface, so there is a limit to how much you can do. A reface of the seats and valves after words will also help (mine appeared to have been done recently so I only lapped them).

Again, this is only my opinion and for my particular application. Everyone's goals are different. But if the engine will be in a regular street driven only car like mine, and you want good driving manners and reliability, then maintaining lots of low end torque is the way to go.
 
Update from the machine shop: Block has been bored. Next step is cleaning the block, then wrapping it for retrieval. Machinist will polish the stock 1500 flat plane crank. Big valve seats are installed in the head and machined. Machinist will install the cam tower and lash the valves, he has shims in stock. He could build the short block for me, but since he is so busy, we decided I will reassemble the short block. Time to go order a cylinder ring compressor. We discussed the merits of the plier type tool vs. the tapered type tool and I will go with the latter. Wiseco.
 
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Short block is assembled. Build sheet appended below. Machinist uninstalled the head studs and trued up the top of the block. I had procured the best quality main and rod bearings available in standard dimension, perfect fit on the newly polished crank. New thrust washers. The rotating assembly is smooth. Machinist advised the following:

  1. 50/50 mixture of Marvel oil and 30 weight in an oil can and re-coat the bores to be sure to avoid any oxidation during methodical, deliberate re-assembly.
  2. Black Permatex on all seals, which is oil and water resistant.
  3. New freeze plugs. The originals are quite rusty. Remove with a drift and hammer, flip in place, pull out with channel locks. Re-install new ones with sealer.
  4. The auxiliary drive bearings were cherry, no need to replace.
  5. Carriers have been cleaned and blasted, ready for new seals and re-installation.
  6. I need to clean the oil pan and pump and evaluate the oil pump (either clean or replace).
block 24 May.jpg

build sheet.jpg


The Euro cam is installed with new seal in the cam box, correctly lashed, torqued to the head ready for install. Machinist noted higher lift and duration than stock US cam.
  1. Machinist sourced trick valve seats (see photo below) that should help airflow, combined with the short bronze valve guides
  2. Surfaced the Euro 10 bolt head
  3. Installed high quality Viton valve seals
valve seat 24 May.jpg

Machinist advised mounting the head with modeling clay on the piston fly cuts, torque to 20 lbs on the head bolts. Install timing belt, then gently rotate engine. Uninstall head and check the piston to valve clearance, should be minimum .100". If that clearance is less, we will enlarge the flycuts. That minimum clearance assures avoiding bending valves, as at high revs connecting rods stretch and clearance becomes shorter.

I asked about my preference for Shell Rotella 15-40w. Strongly suggests use of that and advises against synthetics for older engines. Break in process is to vary operating speed for 500 miles, do not hammer nor baby the engine. Be sure to let off on downhills to build vacuum and seat rings.

Fun to fetch the engine in my 128 wagon yesterday, with fresh suspension, ignition, and exhaust. Machinist quote: "coolest shop truck ever"
hatch.jpg
 
Sounds like a very nice engine build. And your machinist seems to know what he is doing. Sadly where I live there are lots of machine shops but most (all?) do not know a thing about import engines - let alone Fiats. I haven't found one that I trust. Glad that you have a better option. Is he close enough to Thunderhill to do lots of race engine work? Or are you too far from there?

I'd be curious to know what the trick valve seats are.

Regarding replacement of the freeze plugs. I've found all of the ones I've replaced on these engines were a bugger to get out. The "punch in, twist and pull out" approach has never worked for me. That seems to just drive them inside before they can be twisted. And even if they do not drop inside, they are almost impossible to get out after you've twisted them (they are very strong steel, not pliable brass). What works very well for me every time is to drill a small hole in the plug (a bit off to one side), thread a tight sheet-metal screw into that hole, and use a slide-hammer to pull the plug directly out. No punching in or twisting.

While I agree about not using synthetic oil for engine break-in, I do not agree about Rotella. At least not any more. Shell has been forced to reformulate it without the high zinc content to meet stricter federal regulations (including diesel engines). Do some research on it. It is no longer the affordable high zinc option it once was. I'd recommend buying a specific "engine break-in" oil. Or at the very least use a ZDDP additive. But I realize everyone has opinions about oils.
 
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