Quick help needed | 4.6 Tau | cylinder head bolts - torque to yield ?

[pchelka]

Hello

I'm just in the middle of tearing into a v8 4.6 MPI.
Need one information as the service manual does not say anything on this


Can you answer this - are cylinder head bolts:
- Torque to yield (one time use)
- Cylinder head bolts are reusable



Reason for the question, i'm doing swap from sedan into coupe
,but the IAAI car i got has a shot motor (insurance scam basically), t

Tearing into it to asses if it makes sense to fix this on the cheap or get another block.

 

[Aquineas]

I don't know the answer to your question, but if you document your journey via Youtube, you'll get a ton of hits (including me). Cheers!

 

[pchelka]

its in polish though, i have both heads out and crankshaft out
it looks bad as the journal bearings are melted

Considering getting cheap ass fix just to get it running and get the swap done (scout other motor later once i get the electrics sorted out) and 20 head bolts are actually quite expensive in Poland for a 1 time use motor.

Any way any one with an answer please do say something.

 

[carguy75]

Hello

I'm just in the middle of tearing into a v8 4.6 MPI.
Need one information as the service manual does not say anything on this


Can you answer this - are cylinder head bolts:
- Torque to yield (one time use)
- Cylinder head bolts are reusable



Reason for the question, i'm doing swap from sedan into coupe
,but the IAAI car i got has a shot motor (insurance scam basically), t

Tearing into it to asses if it makes sense to fix this on the cheap or get another block.

I do not know the exact specification for the 4.6 head-bolts, but generally head bolts are one-time torque to yield bolts that stretch when installed so they are not reusable once removed.

I am surprised the 4.6 service manual do not state the head bolts as one time use or as torque to yield bolts.

The 2015 Genesis 5.0 service manual does states that the head bolts are one time torque to yield bolts.

 

[pchelka]

It may depend on compression ratio (2015 is 11.5:1 while 2009 4.6 is 10:4:1). Still it seems these bolts maybe be torque to yield

 

[carguy75]

It may depend on compression ratio (2015 is 11.5:1 while 2009 4.6 is 10:4:1). Still it seems these bolts maybe be torque to yield

Many modern head bolts are generally torque-to-yield bolt regardless of compression ratio. However, I can not say for certain that all head bolts are designed that way.

I always used new head-bolts and torqued them by spec using a torque-angle gauge on my LS engines. I never worked on a Hyundai engine, but the 5.0 seem simple enough and standard fare without being overly complicated similar to GM engines. I assume the 4.6 is the same.