1970 LS-5 454 fan blade, 5 or 7???

[Donald A.]

My "new to me" 1970 LS-5 454, original air car currently has a 5 blade fan. It's a very early car, Jan 6th build #133.

Should I have a 7 blade? I've seen some pics of some blade that have a different shape to the end???

thx

[Joe L.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

Don------


1970 with C-60 was originally equipped with a 7 blade fan with unique tip configuration. The tips of each blade have a sharp "spike". This was done to help reduce noise for this fan which had a high blade pitch.

[Donald A.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

Thank you for the reply. I've seen different cars and did not know which was correct.

[Joe L.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

Thank you for the reply. I've seen different cars and did not know which was correct.

Donald------


This is a very difficult (and EXPENSIVE) fan to find. It was used only for the 1970 model year and only on Corvettes with LS-5 and A/C. A similar fan was used for 1971-73 Corvettes with big block and A/C but it had a different fan clutch bolt pattern. It's also difficult to find.

[Dick W.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

Donald------


This is a very difficult (and EXPENSIVE) fan to find. It was used only for the 1970 model year and only on Corvettes with LS-5 and A/C. A similar fan was used for 1971-73 Corvettes with big block and A/C but it had a different fan clutch bolt pattern. It's also difficult to find.

I will look tomorrow, think I have one of each and will make photos with dimensions

[Rich C.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

Donald------


This is a very difficult (and EXPENSIVE) fan to find. It was used only for the 1970 model year and only on Corvettes with LS-5 and A/C. A similar fan was used for 1971-73 Corvettes with big block and A/C but it had a different fan clutch bolt pattern. It's also difficult to find.

I remember keeping an eye out for one at Carlisle, there it was... hanging on the side of a trailer like a trophy!!! $500 was the asking price. Ended up finding a mint one in Hemmings Motor News for $300. Yup, that was a long time ago!

1973 LS-4 454 Coupe (with A/C) owned 24 years
1996 LT-4 CE Coupe, owned 10 months
Victory Hop Devil Ale- currently on tap!

[Donald A.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

I remember keeping an eye out for one at Carlisle, there it was... hanging on the side of a trailer like a trophy!!! $500 was the asking price. Ended up finding a mint one in Hemmings Motor News for $300. Yup, that was a long time ago!

1973 LS-4 454 Coupe (with A/C) owned 24 years
1996 LT-4 CE Coupe, owned 10 months
Victory Hop Devil Ale- currently on tap!

Thanks for the information. I will keep a look out and I will also have to check what bolt pattern I have currently on the fan clutch.

[Donald A.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

All;

Can I revisit this special fan discussion. Can anyone expand on the correct water pump and these bolt pattern differences etc. I'm looking for specific guidance so that I can ensure the right purchase should I come across one.

Thanks

[Joe L.]

Re: 1970 LS-5 454 fan blade, 5 or 7???

All;

Can I revisit this special fan discussion. Can anyone expand on the correct water pump and these bolt pattern differences etc. I'm looking for specific guidance so that I can ensure the right purchase should I come across one.

Thanks

Don-------



The correct water pump casting is GM #3940960, although other castings can be equally functional.

The water pump hub bolt pattern will be a 1-3/4" bolt circle (i.e. measured diagonally). A dual pattern hub (i.e. 8 tapped holes) will work for both 1970 and earlier and 1971 and later.

The fan-to-fan clutch bolt pattern will be a 3" bolt circle.