Air Temp Sensor

[ChrisXS2003]

Does the 280 have an air temp sensor mounted in the front half below the starter?

I have two frankenstien nic engines with no holes for the air temp sensor. Both have unpainted, 7 petal fronts...wondering what they are from.

Chris

[Chummy]

yes they do

[ChrisXS2003]

Does the 225 PM have one as well?

Chris

[MERCing]

Yes they(PM) do but it is mounted on the throttle body(manifold).

[ChrisXS2003]

Thanks for the replies!

I think I've figured it out. I've got 2.4 EFI front halves on 2.5 blocks....sucks!

Chris

[merc326]

are you sure its a 2.4 f/h on a 2.5 block, someone would have to do alot of fabbin to get it to work. sounds like you have a 225 p/m front half. does your front half have the 6 holes on the shifter side of the front half where the injectors plumb into. If you dont then you do have a 225 p/m front, if you do then you may have a 2.4 front. if you do have the 6 injector holes, then look inside the front half after pulling the reeds plate and see if there has been any grinding of the top 2 main bolt holes and also some of the side holes as well. I looked at doing the same thing at one time and it was way to much work to even try. its cheaper to just buy a 2.5 front. just trying to help.
Merc326

[XSive]

Post the serial #'s on the block (by the throttle linkage) and amybe someone can at least figure out what the block is.

[ChrisXS2003]

The fronts do have the 6 injector bosses. So, I know it's an EFI front. The top (2) main bolt holes have been elongated downward to match the block hole pattern (port side is ugly). There is no boss for the air temp sensor. They have also been drilled for the extra (4) bolt mains, but there are no bolts in the extra holes. Torque wrench access probably denied.

One block is a carb block and one is an EFI block, both 2.5 nic blocks (fresh nic). The carb block has no serial number or assembly date. The date stamp is an assembly date....means it was a warranty block replacement at some point in its' life. There are 3/4" long screws threaded into the bleed holes that extend all the way across the ports inside.

The EFI has a date stamp like 1-23-93.

I called Ruck and he said he refused to machine a 2.4 front for a 2.5 block...too much work (said the center mains are smaller in the 2.4 than in the 2.5). He also said the bolt patterns should match if they were 2.5 (any kind) fronts.

I won't know exactly what I have until I can tear them down this winter and go through them right I guess.

I think they're 2.4 fronts

Thanks for help!

Chris

[XSive]

Gee Chris,

Sounds like you've got quite an interesting saga on your hands.. What's the story behind these motors?

[JohnR225]

Sorry Chris... I know what you’re feeling wondering what’s inside, and it doesn’t feel good.

Do your engines have top mounted air temperature sensors?

Best of luck to you.

[merc326]

I went and took a look at one of my 2.4 front halves and it didnt have the air sensor either ,so if the holes are elongated like you say, then it is for sure a 2.4 efi horn front half, which will work fine ,if the center mains were matched correctly and you dont have any air leaks. someone sure wanted it to work. hope this helped.
Merc326

[ChrisXS2003]

I went and took a look at one of my 2.4 front halves and it didnt have the air sensor either ,so if the holes are elongated like you say, then it is for sure a 2.4 efi horn front half, which will work fine ,if the center mains were matched correctly and you dont have any air leaks. someone sure wanted it to work. hope this helped.
Merc326


I did a search and found pics of a 2.4 and a 2.5 front.

The area around the top bearing is quite a bit different. The top bolts are probably running through the seal groove.

The smaller center mains would take a lot to do right. Plug the existing bolt holes, machine some off both block and front sealing faces, re-drill the bolt holes, assemble with dowels and line bore the assembly. Not that hard to do, but expensive.

How much bigger are the 2.5 center mains? Can't tell from pics

Not looking forward to taking them apart because I doubt it was done right.

Chris