2.7 engine swap - '76 into '74 Question

[mmasse]

I am planning to drop a 2.7 engine 1976 into a '74 911S. Is this a straight forward swap?? Any differences or things I should know?

Thanks a lot,

[Bobboloo]

It's pretty straight forward. The main difference between the motors was the exhaust system. Ideally you should keep the 74' exhaust system and install it on the 76' motor. It'll give you extra horsepower and extend the life of the 76' motor. Now's the time to do it since both motors will be out.

I don't know what state your in but you should also remove the smog pump system and plug the holes in the cylinder heads if allowed in your state.

The most important thing is to be extra careful when removing the old exhaust system you don't want to break off any studs. Soak the nuts overnight with PB blaster and then use a torch and heat the nuts until they glow red before you attempt to remove them.

[mmasse]

Originally posted by Bobboloo
It's pretty straight forward. The main difference between the motors was the exhaust system. Ideally you should keep the 74' exhaust system and install it on the 76' motor. It'll give you extra horsepower and extend the life of the 76' motor. Now's the time to do it since both motors will be out.

I don't know what state your in but you should also remove the smog pump system and plug the holes in the cylinder heads if allowed in your state.

The most important thing is to be extra careful when removing the old exhaust system you don't want to break off any studs. Soak the nuts overnight with PB blaster and then use a torch and heat the nuts until they glow red before you attempt to remove them.

Thanks for your reply. Do you know if there is any differences in the wiring?? Thnaks

[Wayne 962]

Originally posted by mmasse
Thanks for your reply. Do you know if there is any differences in the wiring?? Thnaks

There were so many minor variations in the wiring amongst the years, even small differences sometimes between Euro and USA cars. Believe it or not, this is not a super-common swap (most people swap in a 3.0L).

Take the old engine out and compare the wiring harnesses. At the very least, if they are identical, then you should have no problem. If they are different, the quick and easy solution is to keep the 1977 fuel injection on the 1974 engine - since the long blocks are basically the same, you should have no problem.

The 1974 motors came in a 'S' and non-'S' version, the only main difference being the cams and the pistons. All of the 1977 2.7 engines were 'S' models. That said, the CIS system should still work fine on an 'S' or non-'S' longblock, but you may want to double-check the final mixture when you're done...

-Wayne

[pjv911]

Some 76` models had power brakes . It your engine is equipt for that you will need to plug the 1/2" nipple on the air box . But I would recommend exactly what wayne suggested . Swap the entire injection system. Also the fan/alt due to any possible differences with the voltage regulator. Take it all off in one big assembly . Dont drop any hardware down the ports !

Kurt Williams

[mmasse]

[i]... If they are different, the quick and easy solution is to keep the 1977 fuel injection on the 1974 engine - since the long blocks are basically the same, you should have no problem.

The 1974 motors came in a 'S' and non-'S' version, the only main difference being the cams and the pistons. All of the 1977 2.7 engines were 'S' models. That said, the CIS system should still work fine on an 'S' or non-'S' longblock, but you may want to double-check the final mixture when you're done...

-Wayne [/B]

Wayne, sorry but I lost you. You mean to put the '74 injection on the '76 engine??

The reason for doing the swap is that the '74 engine is blown.

Thanks

[pjv911]

Yes thats what he means .