2400 Coupe engine rebuild

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bhiggins2
Posts: 140
Joined: Wed Jun 24, 2020 5:54 pm
Dino: Fiat Dino 2.0 Coupe

Re: 2400 Coupe engine rebuild

Post by bhiggins2 »

Richard,
I had a similar problem with a door mounting bolt on a 1979 Alfa Romeo spider.
The nuts are captured in a nice little square sheet metal box [tack welded to chassis], that can come un-welded.
I had to cut a piece of fender out to access the area, welded the heck out of the retaining box and nut, then welded the fender piece back into place.
It is good to know there is an fix should it become a problem.
Thanks,
Ben.
bhiggins2
Posts: 140
Joined: Wed Jun 24, 2020 5:54 pm
Dino: Fiat Dino 2.0 Coupe

Re: 2400 Coupe engine rebuild

Post by bhiggins2 »

Thanks to doublegarage [Richard] for the suggestion of the hydraulic lift table. It worked great.
I fortunately did not need to make a head puller tool.
My car started easily, idled well and seemed to be a decent driver. I dropped the engine and transmission together to work on the clutch and also to try and figure out where my oil losses were. The engine was excessively burning oil and also leaking oil, mostly while driving. I didn’t really notice the oil burning when driving, either inside the car and I didn’t see any plumes of smoke coming out the exhaust but when idling in the driveway, the burning oil was severely irritating my eyes.
My diagnosis of a worn out clutch was correct. There was zero clutch material left on the pressure plate side of the clutch disk.
I did a compression test and leak-down test with the engine on the engine stand. Normally it would have been done hot, in the car, but this was easier.
Piston#, cold PSI, cold+oil PSI, leakdown %
1, 170, 180, 8
2, 175, 185, 8
3, 190, 200, 8
4, 190, 200, 8
5, 170, 180, 11
6, 195, 205, 8
These numbers wouldn’t usually have me tearing down an engine had it not been burning so much oil.
I might have just cleaned up the engine and replaced gaskets, replaced the clutch and put it all back in the car.
I’ve owned the car for 3 years and the previous owner had it for 11 and there was no records from the previous owner about any engine work. The previous owner sunk a lot of money into just about everything other than engine and transmission.
Upon tear down, I was surprised to see Teflon valve stem seals on all valves and the seals looked OK.
Pistons 2 and 5 both had visual damage from valve strikes [intake and exhaust], but there was no damage or bent valves on 2 or 5, so some sort of valve job must have been done at least 14+ years ago, but they weren't willing to rebuild the bottoms end.
There was a mix of valve guides in the heads. Some were tapered on the combustion side and some appeared to be cut short [squared off] with no taper. Some had a concentric ring pattern inside while others were smooth. Some exhaust valves had play in the guides. Some intake valve stems [most] would not fit down the guide without tapping them through with a punch, so the valves were shrinking/mushrooming and not elongating.
I had checked the cams and valve adjustment when I bought the car and the cams are good. There were a couple [2] of later style shim on top of the cam followers mixed in with the older style shim under cam follower [10] that I replaced. I have a set of drilled cams to install.
I wasn’t planning on a complete engine rebuild but it looks like I need new valve guides, valves, and new pistons, main bearings, rod bearings,………………
The heads and block on the engine that came out of the car are better than the spare blocks and heads I have accumulated. I was planning to build a second engine and then do a swap in the future.
I have been rebuilding 1950s-1970s Alfa Romeo 4 cylinder engines for decades so I have the tools.
I have a lot of questions for those who build their own engines.
I have read the FIAT 2000 engine rebuild manual in the Forum library:
http://www.fiatdinoforum.org/download/file.php?id=106
1. It refers to heating the heads to 250 deg Celsius [482F] for valve guide installation. Is this really necessary? Sure, I could put the head in the powder coating oven, but that is pretty hot – I would worry about warpage. On Alfas, I put the valve guides on dry ice and the head is at room temperature, then ream to size.
2. The manual also refers to grinding [drilling] out the valve guides before removing them. I assume this is so that they deform inwards and not outwards when driving them out. It doesn’t say to what internal diameter you should grind/drill them out. Anyone have an opinion on this?
3. My cylinder liners have no wear lip and some have some shiny spots where there was some piston skirt wear. I am aware that there are 3 piston sizes and 3 corresponding cylinder diameters but I’m not sure I am seeing the values +/- for cylinder to piston clearance. Maybe someone could point that out for me.
4. I know we all have bought parts from the major suppliers [Superformance, Dinoparts, etc.] and we have experienced varying degrees of quality. I would appreciate any advice on whether there are any major differences on parts such as guides, valves, pistons, seals, gaskets, clutches between the two vendors.
5. On gaskets, I see reference to using a Reinz RTV product on the head gaskets. I am used to zero gasket material on Alfa head gaskets and usually the Reinz head gaskets are a premium upgrade. I see Spesso head gaskets listed for sale. Are there better gaskets available for the Dino and is the RTV for just around oil and water pathways or is it used around the combustion chamber as well? There didn’t appear to be any RTV on the head gaskets on the engine I just took apart and no evidence of head gasket failure from combustion chamber outwards. Maybe some oil leaking outwards.
6. I had good oil pressure, but I see the parts places suggesting upgrading the 2000 oil pump to a 2400 oil pump. Is it worth the upgrade?
7. I can’t even imagine trying to replace a starter in the car. That giant boat anchor of a starter wouldn’t even clear the engine mount. Dinoparts sells a smaller, more powerful gear reduction starter. Does anyone have an opinion or experience with using the smaller lighter weight starter? I will assume it is easier to replace on the car if needed. I saw a reference somewhere that said the starter wasn’t unique to the Dino. Is there another FIAT model that has the same bolt pattern and starter gear configuration that works on the Dino? My starter works just fine, but I dread the day I might have to replace it on the car.
8. Are there any timing chains on the market that I should avoid? I guess I will probably upgrade the timing chain gear bearings if I am going to replace the chains.
9. The front coil springs were difficult to remove. I tried my McPherson strut style spring compressors that work on the outside of the springs and that didn’t work. I rented another style spring compressor from the local autoparts store that went inside the spring and that worked, but I still had to man-handle the springs more than I would have liked. I usually restore [paint of powder coat] everything I take off a car before it is put back on the car. Is there a type/brand of spring compressor that works well on the Dino? Fully extended, the spring is almost 24” long but has to be compressed to <12” to get it off the car. I would hate to refinish the springs only to scratch them up on reassembly.
10. There were gobs of RTV squeeze out on the oil pan to block and rear oil cover. There was no gasket between the oil pan and block. I like to use a gasket dressing like Hylomar blue or Yammabond and the OEM gaskets. I put a new water pump and cam cover gaskets on the car when I purchased it and there was zero leakage in those spots. Is there anywhere I should think about using something else?
11. Has anyone passivated the magnesium bits and pieces at home? The chemicals are nasty and not cheap, but I am accumulating parts that should be preserved before storage or use.

Feel free to PM me or email direct at bhiggins2@aol.com
Thanks in advance.
Ben Higgins
1967 FIAT Dino Coupe 2000
Galveston, Texas USA
Attachments
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Engine 2.jpg
Engine 2.jpg (33.84 KiB) Viewed 2847 times
Engine 1.jpg
Engine 1.jpg (30.31 KiB) Viewed 2847 times
clutch pressure plate.jpg
clutch pressure plate.jpg (33.33 KiB) Viewed 2847 times
clutch disk.jpg
clutch disk.jpg (35.17 KiB) Viewed 2847 times
Scalino
Posts: 179
Joined: Mon Jul 24, 2017 7:22 pm
Dino: Fiat Dino 2.4 Spider
Location: The Netherlands

Re: 2400 Coupe engine rebuild

Post by Scalino »

I do not have personal experience (yet, on the list...), but there is a post on the forum with pictures showing the spring compressor type which supposedly works well for the front springs: http://www.fiatdinoforum.org/viewtopic. ... ssor#p3957
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ThomasK
Posts: 187
Joined: Mon Dec 30, 2013 12:44 pm
Dino: Fiat Dino 2.4 Coupe

Re: 2400 Coupe engine rebuild

Post by ThomasK »

Right, you need these inner spanners with the "plates" and then to Place them as much up and down as possible - then it works very well.
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DOMCHA31
Posts: 15
Joined: Mon Dec 30, 2013 3:37 pm
Dino: No Dino (yet)

Re: 2400 Coupe engine rebuild

Post by DOMCHA31 »

Hello,

Here is my solution which works with our Dinos

The compressor is cheap and vey easely found on the net

I hope this helps

Dominique
Attachments
spring.jpg
bhiggins2
Posts: 140
Joined: Wed Jun 24, 2020 5:54 pm
Dino: Fiat Dino 2.0 Coupe

Re: 2400 Coupe engine rebuild

Post by bhiggins2 »

Thanks to those who replied about the coil spring compressors.
The one I used to get the springs off was sort of a combination of the two models you shared. Photos attached. The issue was the lower portion was on the thick side and I had to pound it in between the coils to properly seat and even then, it barely compressed enough to get the spring out.
I ordered one of the style with the steel disk at the top and bottom and will I see how that works.
Ben.
Attachments
thumbnail (22).jpg
spring 1.jpg
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doublegarage
Posts: 212
Joined: Thu Nov 14, 2013 4:22 am
Dino: Fiat Dino 2.4 Coupe
Location: California, USA

Re: 2400 Coupe engine rebuild

Post by doublegarage »

Hi Ben,

Good to see your engine out and on the same lift-cart I used from HarborFreight.

9. The spring compressor shown by Dominique was the version I eventually used successfully - but that was after having bought 3 others that were pretty hopeless - 2 of them dangerously so. I think the main problem is the springs (on a 2400 anyway) being recessed up into the bodywork with the top coils shrouded by sheetmetal - so you can't get to the top of the spring with the typical external compressors. The type that goes inside the spring is the way to go.

Some other questions you asked.
5. I also have Alfas and never use any sealant on the Reinz headgaskets. I bought the Elring gaskets from Superformance that are supposed to be an upgrade on Spesso. I've just torqued the head and I left it dry.

6. 2400 oil pump - I have a 2400 oil pump but the gears seemed noisy so I decided to buy a new set from Sformance. But when re-assembling the front cover (with attached pump) I could not get the oil-pump to turn, the new gears were too long. So I would say, if you decided to upgrade, be prepared to do some machine work on brand new parts.

7. The starter/engine mount/manifold together make a sort of unsolvable 3D puzzle. I'm sure there's an easy way but I've never found it. I do have one of those gear driven starters on another car (Fulvia) and it's great but I've always been concerned whether one would fit in that area of the Dino engine. They're a different shape. Think of it as..where the solenoid is on a conventional starter, that's where the little Denso motor sits on the modern ones. The motor is able to be rotated around the rest of the starter body, so you can pick the angle you want it to point at. I like the ones made by Wosp.
https://www.wosperformance.co.uk/starte ... rter-motor
Note that's 2400cc specific - there's a dealer in California to contact for more info.

8. My timing chain drive bearings were the most worn out bearing I've ever removed from an engine. Makes you feel good that you took it all apart for a reason. I upgraded to self-aligning (2-row) bearings

10. I use Permatex Ultra-grey everywhere on Alfas and that seems to work. My Dino engine got the same treatment but the engine is still out so we don't know yet.

11. I enquired about passivation (Dow-7) from a place in LA that I know can do it - but was told a) $1200 lot charge, b) it might not work and c) was sent pictures of it having failed. So I gave up and used Cerakote - the guy I used matched a Cerakote colour to the underside of my valve covers. Nobody has any idea what these looked like 50 years ago, but from all the pictures I've studied, I think it's pretty close. Should also be 100x more durable than passivate and clean up easily
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doublegarage
Posts: 212
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Dino: Fiat Dino 2.4 Coupe
Location: California, USA

Re: 2400 Coupe engine rebuild

Post by doublegarage »

My engine (2400 Coupe) is finally coming back together after various showstoppers along the way. Most of them caused by incorrect or poor quality parts supplied. But those problems are now resolved, I think.

The heads have been reconditioned (needed lots of welding to mating surfaces), valve job etc, Therefore I needed to reset valve clearances and did that months ago with the heads on the bench. Now that they're on the block and torqued, I'm finding that the clearances have tightened up - many of them are at (or beyond) the low end of the spec.

For instance - on one cylinder, the intake lash/clearance spec is 0.15-0.20mm. MIne is now sitting at 0.14-0.15. The shims are sized 0.05mm apart - so my choices are 0.14-0.15 or 0.19-0.20mm. What would you do - my 'thought' is that the clearances will tend to tighten over time - as the valve "settles" into its seat, therefore I should increase lash closer to 0.20mm But I'm not sure whether that's a good assumption? When I did the shims originally it was about 50/50, some too tight, some too loose. But that could just be bad maintenance. what do you think, where do you set the valve clearances - large or small?

Thanks,

-Richard
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ThomasK
Posts: 187
Joined: Mon Dec 30, 2013 12:44 pm
Dino: Fiat Dino 2.4 Coupe

Re: 2400 Coupe engine rebuild

Post by ThomasK »

Hi Richard, calve clearances are be defined in the Fiat manuals on 0,2 inlet and 0,4 on outlet as in the Ferrari specs it’s ( for the same engine!) 0,15 and 0,30.

So I go for the 0,2 and 0,4 but in cases like you describe go for the closer by and lower alternative. But in your example if to choose between 0.14/15 or .19/20 I would stay closer to 0,20.

I hope that helps.
KR Thomas
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doublegarage
Posts: 212
Joined: Thu Nov 14, 2013 4:22 am
Dino: Fiat Dino 2.4 Coupe
Location: California, USA

Re: 2400 Coupe engine rebuild

Post by doublegarage »

Hi Thomas, yes that really helps, thank you.

After reading your comment I went looking for some Fiat documentation and found 3 places where the larger (0.40-0.45mm) exhaust tappet clearance is quoted, as you said. I was using the USA Ferrari 246 engine build manual which quotes the smaller (0.23-0.30mm) clearance.

Interesting that they decided on different clearances for the identical engine - all built by Fiat in fact. Maybe Ferrari finding a little extra zip with smaller clearance, but also happy with more regular/expensive maintenance? Don't know.

I ordered some more shims and will re-set the tappets to ~0.20mm inlet and ~0.40mm exhaust.

Thanks again,

-Richard
valve clearances Fiat manual 3.png
valve clearances Fiat manual 1.png
valve clearances ferrari manual.png
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