500 miles on '82 FI rebuild

[bran100]

Now that I have about 500 miles on my home-rebuild, I want to retorque the necessary bolts.

What's the process for this, do you back off one bolt at a time, then torque? I'm assuming you back off first, and you do these one at a time?

Aside from the head, are there other areas I should particularly pay attention to while I'm digging in? Oil change is an given.

BTW, it runs great, but still not the power I was hoping for with 4mm dome pistons, Beek's head work, Mark's 274FI cams, lightened flywheel, and balanced rods/pistons. I can tell it's a bit quicker, and much smoother, just not "fast". I still need to take on the stock exhaust, stock ignition and installation of Jason's adjustable cam gears, so it only gets better, right?

Lots of rebuild pics in my signature line below.

Thanks,
Brandon

[RoyBatty]

I'd go over the head bolts and cam tower bolts to recheck torques.
When doing this I prefer to use a torque meter type wrench instead of a clicker.

What are you expecting for "fast".
Have you checked 0 to 60 times?
How do they compare to stock?

[bran100]

"fast" is such a relative term, so perhaps I should've stayed away from it. Essentially, I don't feel the pull, pushing me back in my seat, I don't see that I jump off the line at a stoplight much, if any, faster than the typical sedan next to me, and when I discuss the car with other non-Fiat owners, I have to qualify the discussion by saying "it's not fast, but it's a lot of fun".

It really is a fun car, I just wish I was equally impressed with the speed. Hoping the adjustable cam gears dialed in+2 1/4 exhaust+distributorless ignition will add a few more HP.

[majicwrench]

In the good ole days when we typicly retorqued head bolts you would back them off about 1/4 turn and then retorque. Do em one at a time.
Modern gaskets usually don't require retorque. Isn't gonna hurt anything to do it.

Fast.....that "pull, pushing me back in my seat" is torque, not horsepwer, a lot of that racey stuff the torque, esp at low speeds goes down. Aftermarket ignition not going to change much of anything unless there currently something wrong with your system.
Lightened flywheel makes car a bit harder to get rolling.All that mass spinning around gets car rolling wo slowing engine down as you release clutch.
You can check you cam timing wo adjustable pulleys. And you should. If you are not into checking your cam timing, adj pulleys not gonna do you any good, you HAVE to be able to accurately check cam timing to be able to get anything out of adj pulleys.
Stock exh might be limiting things on top end, but not likely gonna affect much that "pull, pushing me back". Do you currently have a 4 into 2 manifold?

Ignition timing is a big part of power, did you actually check the tdc mark on crank pulley?? Screwdriver down plug hole is NOT the way to do this. Verify total advance??
Keith

[backyardbill]

bran100: how did you prep/restore your exhaust manifold to get it so nice and shiny?
Nice job on your picture set.

[So Cal Mark]

those cams are torque cams, so it should have good low and mid range torque if everything is set correctly

[bran100]

bran100: how did you prep/restore your exhaust manifold to get it so nice and shiny?
Nice job on your picture set.

It's just high temp exhaust paint after degreasing and sandblasting the 4-2-1 manifold.

[bran100]

Keith, the adjustable cam gears are my next project, and will definitely coincide with degreeing the cams to the best of my ability. I've been trying to read a lot about how to properly do this. Checking the crank timing wasn't on my radar though, so thanks for bringing that up.

Brandon

[djape1977]

you must have done something wrong with timing

[majicwrench]

To accurately degree cams, you HAVE to know EXACTLY where TDC is, not just the groove in the pulley. And really, to get the full benefit of adj cam gears, you need to run on dyno, change maybe 1 deg, try again etc. Seat of the pants is not a good way to know if changing the cam timing made any difference.
Keith

[michaelj]

Gents, couple things please.
First off, Bran, I am at a similar point as you. I put in the domes, stage one cams from Mark, Empi carb, bigger valves, lightened flywheel, and just hit 500 miles. I too feel that not much has changed. Yes its tons more smooth. The old carb sucked and I had a dead cylinder. I expected a nice jump in feel, not so much. But I am attributing a lot of that to the old cast iron exhaust manifold still on there. My finely built 1.8 liter Fiat pump cant move the air thru it. Waiting on an exhaust header that I should have in a week or two. Then I am going to the dyno.

I don't have the adjustable pulleys yet . Waiting for Jason Miller to get back into the swing of it.

That being said, I determined top dead center using a dial indicator on the block. Is that how you guys do it? I marked the crank pulley at that point. I tried to pick the "middle" of the top but its hard to say if I hit that exactly. Certainly better than the screwdriver in the hole. Curious how you guys do it if the head is still attached. SOmetimes that is the case.

How do you guys set your cam pulleys up? I just used the factory marks since all I did really was change the total lift. Runs good, but hoping for more. And I would think the adjustable pulleys would help a lot since moving a whole tooth on the cog is a big jump. How do you do it without those?

Also, I have tried to retighten bolts twice and they haven't budged since new. Holding well!

Only rebuilt two engines, one chevy and this 1.8 so pardon the novice questions. Thanks gents!

Mike

[djape1977]

depends on what you're used to. if you daily driver has 200hp, fiat will feel weak whatever you do to it.

on the other hand, i've had in my workshop 1971 124 spider with 2 litre engine from fiat 132 installed. bog standard 112hp eurospec 2 litre. it came in for a clutch change. when i test drove it before replacing the clutch, it felt weak. no more pull than 70ish hp, judging by the feel of it. the engine ran smooth, was happy to rev up to 6.5k rpm, but simply had no power. when i asked the owner about it he said that it was ok, as it was since he got it.
well, it wouldn't be me if i just left it alone and swapped the clutch.
after replacing the clutch, i lined up cam marks and it turned out that it was off by two teeth on crank pulley. i removed timing belt, found TDC with a screwdriver, and put the belt back on. oh boy what a diference! brand new hancoock 205/60/13 tyres would smoke all the way tru first gear, than continue smoking in second up to 80ish kph while i was keeping the car in a straight line and back end was fighting hard to step out sideways.
my guess is that this particular car had it's original 10/43 diff so i would expect the later cars with 10/39 to be little less agressive, but still prvoide plenty tyre smoke at least in first gear.
if you don't have this after engine rebuild, you've done something wrong and you need to find someone who knows his way around fiats.
i've seen this kind of problem too often and from my experience, most cases of lack of power are due to wrong timing.

[majicwrench]

Best way to find TDC is to create something that will cause a positive stop to the crank. If head off, get a hunk of plate steel, drill a 3/8 16 hole (or anything) in it, bolt it to head, so you can run you 3/8 16 (or whatever) bolt down far enough it will stop piston from reaching TDC. Now roll engine over till piston hits stop. Mark pulley. Roll other way till stop. Mark pulley. Exactly halfway between those two marks is TDC.
With head on, you still need to stop the piston. Take an old plug and drive the center out of it. Run a long 1/4 20 threadall thru it, put a nut on both ends. Bolt will have to have the points ground a bit to fit down hole. Then same thing, roll engine till stop, mark, roll other way, stop, mark, tween marks is TDC.

With dial indicator and head off (or I suppose on?) you could do same thing, but you would want to roll piston up till it move indicator some set amount, say .100, mark, then roll other way till .100 of movement, mark, 1/2 tween is TDC

Piston floats for a few degrees right around TDC, really hard to find tdc (for me) wo doing the above. Degreeing cams, there is not point unless you can get less than a degree of error. Although you could simple advance your cam timing wo knowing where you are at. Adv cams will (generally) produce a bit more mid range.

If you have surfaced your head/deck, you have already retarded your timing. Everybody wants to surface these things wo thinking about the results.

[djape1977]

after you change enough timing belts, you can find tdc no prob. i do agree that for precise timing you'd need to use some fancy tools, but 99% of fiat owners are more than happy with properly timed engine, not precisely timed one.

adjustable pulleys are very practical, because usually, when you find tdc and line up the cam pulley marks, at least one of cam gears is in such position that timing belt tooth sits exactly on cam gear tooth. adjustable cam gear solves this problem. othervise, i usually just slightly turn the cams towards the centre line of engine untill belt sits right. this creates slight overlap in valves opening. wether this is correct practice is debatable, but works fine for me.

[bradartigue]

Now that I have about 500 miles on my home-rebuild, I want to retorque the necessary bolts.

What's the process for this, do you back off one bolt at a time, then torque? I'm assuming you back off first, and you do these one at a time?

Aside from the head, are there other areas I should particularly pay attention to while I'm digging in? Oil change is an given.

BTW, it runs great, but still not the power I was hoping for with 4mm dome pistons, Beek's head work, Mark's 274FI cams, lightened flywheel, and balanced rods/pistons. I can tell it's a bit quicker, and much smoother, just not "fast". I still need to take on the stock exhaust, stock ignition and installation of Jason's adjustable cam gears, so it only gets better, right?

Lots of rebuild pics in my signature line below.

Thanks,
Brandon

Brandon if you are running stock cam wheels with all of those modifications then you are most definitely out of time. You need the adjustable gears to get those cams into the right positions relative to your crankshaft. Also if you have hi-po cams and you find it "smoother" than stock then something is amiss. It should be a little more choppy than stock, telling me even more that you need to get those cams lined up right.

Take on the cam wheels before you do anything else; the exhaust and ignition aren't causing you problems right now.