My Alfa Romeo 33 rebuild - FIRST TIMER

[Brit01]

Thanks Guy.

99% sure they are standard Alfa gaskets but I'm checking.

These are the sturdy standard re-usable head bolts.

8.3-8.9 kgs torque setting.

[Brit01]

On the INA tappet box it says to break in the new tappets for 4 minutes at 2500 rpm.

Why such a short time when most engine builders recommend 10-15 minutes?

[TomLouwrier]

Short answer: because INA made them.

Seriously: production methods, surface finish and tolerances have improved lots in the last 20 years or so. On the other hand 'rules of thumb' that are common wisdom tend to lag behind by about the same amount.
Mind you: INA didn't make your new cam, just the tappets. Feel free to break the combo in for longer than those 4 minutes.

regards
Tom

[WhizzMan]

Tim has a fair point. For racing engines, all bets are off.

This is a street engine, all gaskets for the 8V boxer I've seen are thermosetting polymer and the head bolts are rather over sized for the application. I myself wouldn't feel secure about re-torquing bolts, when there is a chemically changed plastic compound in between the head and block. Manufacturer instructions usually contain warnings about damaging the gasket by trying to re-torque and I doubt those warning have no merit at all. Also, I've never seen anyone I know that works with these engines (and I know a few here in the Netherlands that do so for a living) re-torque them.

[Brit01]

all gaskets for the 8V boxer I've seen are thermosetting polymer and the head bolts are rather over sized for the application. I myself wouldn't feel secure about re-torquing bolts,

Thanks Whizzman and Tom. Been trying to find out if they are thermosetting types and am not sure. Yes you are right, the bolts are very sturdy (see the picture) and I shudder at the thought of loosening them and re-tightening them again.

On the Alfa forum I'd say 50% of the members re-torque and the other half never and the latter have never had issues.

I will try contacting the supplier again to see if they have more info.

[Brit01]

Been told it's a Payen/Tako head gasket.

Still searching if it's a re-torque type or not as I saw a post here that they make both types.

It has a red line around the edge with I heard is the good type of Tako gasket with a sealant.

[Brit01]

Total misunderstanding with the provider - NO they are not the Tako/Payen type.
Looks like a re-torque should be done as I believe the thermosetting polymer type are expensive and I did not pay a lot for the gaskets but still trying to extract more information from them.

Update : from athena

[Guy Croft]

You should not worry about this setup. If the regime is a simple torque sequence - tighten according to OE regime. Run up to temp, leave overnight. Next day with engine fully cold relax each bolt a tiny fraction in turn (don't loosen them all at once) and then torque up again. You may be interested to know that after final torque-up I always go round the bolts with a long T bar and do 'final settle' by hand. Iam not suggesting I have an usually skilled touch in that regard but one can easily feel if the bolts are secure and pull-up any that 'move'. I am talking 1/16 - 1/8 turn absolute tops. It may impose a higher torque but that doesn't matter as the recommended setting will be well below the level likely to cause thread damage or yield. Torque is related to induced stress only to within some 20% accuracy (based on a good lubrication regime) so you can see doing that can equalise them very satisfactorily.

G

[Brit01]

Thanks Guy for your sound advice. Comforting to know that the bolts/threads have a 20% leeway in regards to induced stress.

I will follow the OE instructions and re-torque after the first heat cycle. I assume the first step of untightening a tiny amount will not break any seal already made. OE specs recommend 1/4 turn but I think I will just untighten them until they release (1/4 turn seems like a fair amount IMO).
Probably advisable to spray some lube around the washers/bolt head to re-lube them?

Seems to be quite a controversial topic amongst engine builders like oil types/viscisities discussions.

[Guy Croft]

Just undo enough to feel the load relax a bit and break the friction betw the bolt head and washer/head. 1/8-1/4 turn yes. Just do one at a time. If you undo them too much the gasket may leak. Assuming you have put anti-seize on threads and oiled the underheads - you don't need to relubricate.

I'm afraid engine builders' methods do vary, thats experience for you..

G

[WhizzMan]

I have no idea how inflated the prices are where you live, but I think I've paid around the 19 Euro mark for the last Alfa 8V boxer head gasket. That was a polymer type gasket. They are a rather affordable part, in my opinion.

I think you have some excellent advice from more than one source, both supporting re-torque and "leave as be". You have all the arguments why you'd want to do it, or why not. Now it's up to you to decide whether you want to or just leave it be.

Is she running yet, or is the weather holding you back?

[Guy Croft]

Impeccable logic Homme!

G

[Brit01]

Yes indeed various pros and cons of re-torquing from different sources.

I bought my gasket set from The Gasket Shop in the UK (but I live in Uruguay - as an expat). Athena brand. around 26 pounds for the heads, cam supports, inlet manifolds, and 8 valve seals.

Hopefully ready to fill with oil tomorrow, prime, and then break in the cams/tappets. Leave overnight till Sunday, re-torque and then go for a light drive to test.

[Guy Croft]

well, best of English person-ish!

Hope it goes well for you in every way.

G

[Brit01]

Thanks Guy.

Fingers crossed for a good start up.