OHC conversion

[Invectivus]

Has anyone considered an OHC conversion for the AL head? I was looking at the tempest OHC from pontiac which looks *feasable* to use the same process for ours with decent fab skills. There's a tempest someone trys to sell on ebay every once in a while for 6 hundred that I'm thinking of picking up for guidance.

 

[Frankenstang]

viewtopic.php?f=1&t=50295

 

[Invectivus]

yeah, I've seen that (have it book marked). I was thinking of working with a buddy to draw up a justified pedistel plate to move the rocker pivot to the drivers side (like in the tempest OHC) and use tempest style rockers.

The first issue would be the Cam assembly over the head, probably have to double the mounting spots to maintain cam frame rigidity (which means welding aluminum stock, drilling, and tapping), and need to see what the tempest uses for oil delivery. I expect a custom cam would be needed, but that's just a design point. Tempest almost looks like an oil through cam design.

Another issue would be timing (probably gear) and a timing cover, and might need custom pulley's to move the belts out as well.

 

[aussie7mains]

Why?
There is a SOHC version of the aussie 6 already, they came out in 1988 and ran through to 2002 then the engine became DOHC 4 valve.
The bolt pattern on the block looks to be unchanged all the way through, so all the heads should at least sit on the blocks, but there will be timing cover / pushrod hole problems.
Why would you even attempt to fit a Pontiac head to the six?
The OHC version of the 4litre six can produce up to 172kW in the VCT version, I have one in my Falcon and they go very well even in the 1600kg Fairmont version.
The OHC head would most likely bolt onto the earlier blocks and you could make a timing cover if you were really serious, then there is most likely a problem with the openings on the block surface.
If you really want a shit hot six, then just get the Aussie OHC 4l and dump it in your car, its very similar to all the earlier sixes in layout and size.
If you want to see one in a Mustang search on youtube for "1tuff65" this is a turbo propane OHC in a 65 mustang thats has run 9 second ETs and is street driven.
A7M

 

[Invectivus]

Firstly, I know all about the OHC, DOHC engines, but IIRC they require matching blocks (which isn't a huge delta from a head, cost and shipping wise), but they're a bugger to get here. I have a coworker in class with me from the islands, and have been thinking if I want to make a bulk buy over there in prep for an expected trip to Aus/NZ to ship home depending on cargo container costs.

Secondly, I have a hot rodder heart (and I'm a dreamer), which makes me want to do things like not leave well enough alone. The idea of fabbing up a tempest 'style' OHC conversion (not retrofitting actual pontiac parts) would be because I could, not because there wasn't a more cost effective option currently available. I have an 87 EFI crossflow in the garage, and I'm fairly confident it would get marginally better power with significantly lower cost than engineering something new.

I admit, though, there's naught more awesome than a DOHC 4V.