Sump gasket

#1
I currently have a bad oil leak from what looks like the back of my sump gasket.
Having looked for a replacement I was confused by the array of different gasket materials - cork / composite / rubber / heavy duty rubber.
Can anyone recommend the best gasket for the SD1 V8.
Also should gasket sealant be used and if so what is a recommended product.

Thanks
 

jp928

Well-Known Member
#2
Might not help, but here is my experience. Big problem with alloy blocks is the bolts tend to loosen because their tension is low - typically <10 lb/ft. This low a tension is difficult to produce without a low range wrench - best is a 1/4" drive, with a short bar to give you some feel. The bolt tension is low because higher loads tend to squash the soft gaskets out of place and produce leaks. Hence I prefer composite gaskets as they are more robust against squashing out. A good way to prevent squashing would be anti-squash rings like the newer rocker cover gaskets. Porsche 928s have the same problems, despite having around 30 x M6 bolts, torqued at 7 lb/ft. To get loctite or similar to work here the bolt holes need to be CLEAN, not the easiest thing to do properly. Some 928 people fit studs to reduce the squashing. As for sealants, I have had good results with Permatex Ultra Grey on metal to metal joints (eg MX5 or R2000 sumps), Loctite no3 non hardening or Hylomar SQ32 on gaskets. I find the area of thread sealants and anti seize very confusing - water pump bolts come to mind.
 

jp928

Well-Known Member
#4
Horses for courses, correct tools for specific jobs. I have accumulated several torque wrenches over the years - 1/4 drive ,10" long; 3/8 drive 12" long - most used; 1/2 drive digital 18" long; 1/2 drive 30" long for the big numbers - 200lb/ft front crank bolt etc. This last also makes wheel nuts from 65 to 95 lb/ft a piece of cake, barely any effort required. Shout yourself a nice new tool on birthdays and Xmas!
 

quattro

Administrator
Staff member
#5
I bought a pair from Halfords years ago. One (3/8" drive) does 0 - 40 lb/ft and the bigger 1/2" goes from 20 to 150lb/ft.

The build manual on Sparky's engine says first torque on the main caps, which I was doing yesterday, should be 4lb/ft so very handy. Both of them have lifetime guarantees as well.
 
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