Log to Centerise Exhaust Manifolds
 

Currently have a `81 Scarab 30` Type "S" with twin BBC that have the old "Log" style exhaust manifolds that needs replacing. All factory set up with TRS drives and thru hull exhaust connecting the exhaust risers to the exhaust tips via rubber exhaust hose.Can any one tell me if I switch to the center rise manifolds such as the Gil/TRS manifolds and tails, will it fit the current thru transom exhaust tip hole location or will I need to plug & glass the old exhaust tip holes and drill new holes. I know that I will need to enlarge the current holes because the current setup is for 3" exhaust and the Gill/TRS is 4".

Thanks to all who respond in advance,

Cliff

Cliff, i did that mod years back on a TRS boat. You should be fine as long as the risers for the gils, were from a standard trs setup . Meaning no custom riser height, or for bravo setup. When enlarging your holes to 4.5 inch, , which should be 3.5 inch now, use a 3.5inch hole saw, inside a 4.5 holesaw as a guide. Works great.

and be careful, that big of a holesaw can catch hard. If your using a big corded drill it can rip out of your hand. I have a friend who is missing a finger or 2 the cord grabbed during a similar buffer accident.

@ MILD THUNDER,

Thank you for your response, I forgot to mention that it currently has the MercTrans and not the Velvet Drives, I believe that the Velvet Drives push the whole engine/trans assembly approx. 9" forward but with this set up you are able to run the "Top Mount" starter bell housings. Can you please tell me what type of transmissions did you have when you did your update?

Thanks,
Cliff

@ phragle,

Excellent point to make about the drill and bit hazards, I plan on using a pneumatic drill from work it will not "grab" and stop like a electric drill but rather gradually slow down and then stop. We have had many injuries at work from electric drills grabbing and stopping.

Thanks again,
Cliff