1608 motor rebuild

[70spider]

Fall is upon us and Winter not far off, so I am getting ready to do my first motor rebuild. I have read a ton and have two shop manuals, all the torque specs, and when I tore down the motor I took lots of pictures and put all the parts in zip lock bags with a description card. My plan is to get around 125 reliable hp from it so any thoughts and suggestions would be greatly appriciated. I have an 1800 intake with a 32/36 DFEV carb, forged pistons from Csaba, and I plan to get a lightened flywheel, headers, and a distributorless ignition. I will need to get a new intake cam, the donor motor was missing it. So can I get 125hp from the stock cams or do I need to get performance ones?
I am taking the block to the machine shop in a few weeks and was wondering do I get the crank polished?

Thanks Pesto

[vandor]

I think it would be hard to get 125 Hp from a 1608 with stock cams. The Euro version with twin IDFs made 110 hp.

[70spider]

I thought I was being a little optimistic on HP. I'll build it with what I can afford to put in it and get what I get, which will be mega fun anyway. What about crank polishing?

[seabeelt]

Just my 2 Cents seat of the pants observation from my 1608. Car is all stock and has the 4-2-1 exhaust. I upgraded to Mark Allison's Computronix. No noticible increase in HP, but huge comfort in not having to mess with the points. Changed from the DHSA-3 to dual IDF 13/15s - Big seat of the pants fun increase. Still running the mechanical fuel pump and have plenty of pressure at the carbs at WOT. Exhaust and intake manifold ports seem to be perfect match to the gasket and to the head with no overlap, so good flow. May or may not put more agressive cams in it. Dont know the actual HP, but the car has plenty of zip!! and I have a big smile on my face. Cost of the carbs and manifold. $600. From where I sit, thats a pretty inexpensive fun HP driver experience increase in performance. Again just my 2 cents.
r/

[70spider]

Thanks for the testimonial on the 1608. The reason I bought a Fiat 124 Spider was I test drove a 1971 1608 and thought it was a blast. My 1970 has the 1438 and it to is a blast (not as quick as the 1971) and the motor needs a rebuild so I thought why not rebuild a 1608 while I still drive the car .
I was thinking about dual IDFs, but arn't dual carbs hard to synchronize?
The main reason I was talking about performance cams is the fact that the motor I bought did not have an intake cam and finding new stock cams is a bit difficult. Allison has a set of mild performance cams, granted they are a regrind, but at 300 for the pair it seems fair.

[seabeelt]

IDFs are not hard to tune at all. Problems arise when folks keep messing with them. Read the IDF post at the beginning of the engine and tuning section. Also check out http://www.kendickson.com/car/idf/idf/index.html. Alot of good info there. Plus plenty of help here on the forum. Try Danny at http://www.funimported.com/ for the cam or http://www.midwest-bayless.com/storefro ... fid=208227. There is also a salvage yard in Atlanta. cant remember the name off the top of my head, but they are on ebay all the time and have a huge selection of parts as well.
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[fiatfactory]

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[70spider]

fiatfactory thanks for the input.
Here is what I have so far:
-Pistons/Rings from AR (Csaba) he had to have them special made due to the fact it seems there is no-one that have 1608 pistons.
- I am going to have the machine shop clean the block, deck it, bore to 80.4mm, grind the crank and balance the rotating assembly.
- I am trying to get the best bearings possible but need to see what size to get after the machine shop work.
- As far as the intake system I have an 1800 intake with a Weber 32/36 DFEV carb, eventually I may upgrade to the twin carbs (depends on how much Uncle Sam lets me have back).
What I plan on:
- Upgradeing the exhaust, not sure which header to go with.
-I plan on getting a lightened flywheel.
-As far as the cylinder head work I can't find anyone local so I am going to have to outsource it.
- I would like to buy new cams but I can't seem to find any. AR has some Guy Crofts but I fear the profile might be to radicle for street use. I just want to keep up with modern trafiic not race.
- My little 1438 does an ok job, it is just the 0 to 60 is a bit on the slow side. I am constantly having people ride my ass when I am trying to get up to highway speed .

Well agian thanks for the input. Pesto

[djape1977]

be sure to deliver pistons to machine shop together with block. they need to over bore acording to pistons, not necesarily to 80.4, more likely 80.38 or 80.05 etc, each bore acording to piston

[baltobernie]

Good stuff from SteveC, I would only suggest trading dollars from lightened flywheel to adjustable cam wheels, so you can restore cam timing to designer's intentions once you've changed the dimensions of the block/head. I'd consider starting with the stock camshafts, maybe tweak them a little with the adjustable gears, and see if you're happy with the results. The stock cams are pretty good, and it's always better to err on the conservative side with a street motor. Post for a stock intake cam in Parts Wanted.

Regarding the crankshaft; follow the machine shop's recommendations. Only grind if necessary, doing so removes the factory surface treatment. Decide on your intake pulley arrangement (I cut one groove off mine), and take it with the motor to the machine shop, so they can balance the entire assembly.

I wish you'd have posted this sooner. I bet you'd have gotten several responses urging you to move up to 2L. With more compression, single-plane and 32/36, 4-2-1 exhaust, you'd be looking easily at 125 HP and enough torque to keep the minivans off your tail.

[70spider]

I am going to take everything (pistons, connecting rods, new wrist pins, crank and the block) to the machine shop, they said they can press fit the pistons for me. As for the 2L option I thought about it but people had concerns about hood clearence, plus I got a good 1608 donor motor from Csaba.
About the cams, where can I get new stock cams at? Mid-West doesn't seem to have any narrow lobe ones.

Also I don't want to seem stupid, but what was meant by

Decide on your intake pulley arrangement (I cut one groove off mine), and take it with the motor to the machine shop, so they can balance the entire assembly

Thanks for the input, gives me food for thought, I figure its going to take me about 6 months to get this done.
Pesto

[baltobernie]

I am going to take everything (pistons, connecting rods, new wrist pins, crank and the block) to the machine shop, they said they can press fit the pistons for me.

Yes, and take the front pulley you intend to use, too. These engines don't have a harmonic balancer like American V-8s. They are, however, externally balanced at the factory. If you look at the back side of a Fiat TC front accessory pulley, you will see several indentations that were drilled to lighten the heavy spot of the entire rotating assembly. Even if you're using the donor 1608 in its entirety (all accessories, including front pulley), you want to have the pulley installed and balanced at the machine shop. Decide on your alternator location, and any other items to be driven by this pulley. I needed only two grooves; one for the water pump, the other for the alternator, and I had a 3-groove pulley on the donor engine I had. By cutting off the third groove, I changed the overall balance.

About the cams, where can I get new stock cams at? Mid-West doesn't seem to have any narrow lobe ones.

You can use a used camshaft; ask for one on the board.

[70spider]

Thanks for all the advice, especially about the pulley. I figure I'll put the block together this winter and have the cylinder head professional done later, when I get a job . I am about to run out of funds for the car. I had figured on about 6K budget for the car and I will exhaust that after I get the suspension done. So the list of undone things gets longer , it will all be worth it in the end. The car is a blast to drive in its delapitated state, I can't even imagine what a good running Spider feels like to drive. Again thanks guys, cheers and have a great day, Pesto.

[joelittel]

I have a set of stock cams that came off my 2L, if they interest you let me know. My car is fuel injected, not sure if that matters.

Joe

[SoFlaFiat]

You beat me to it Joe...
I also have some stock cams laying about. Always good to post it the wanted section here Pesto!!