273 Questions

[cactuscarl]

Buddy of mine asked me to post the following questions:

1. Does anyone know what the cam specs were for the 273 Powerpak motors?

2. Are 273 powerpak pistons (10.5:1 compression) available anywhere?

Thanks,
Jeff

 

[barracudadave67]

Cactuscarl
To my knowledge 273 Hipo pistons are not available. You wuold probably have to find a set of NOS. I have a set of reg flat top pistons and rings .030 over if you are interested.
Cam specs for 273 4-bbl engines in 67 were,From 67 Factoy Service Manual
Intake opens(BTC) 14*
Intake closes(ABC) 54*
Exhaust opens(BBC) 56*
Exhaust closes (ATC) 12*
Valve over lap 26*
Intake vale duration 248*
Exhaust valve duration 248*
Solid lifters from factory should be set @
Intake .013
Exhaust .021
Set with engine hot.
Use the mopar valve lash chart to set lifters.
Hope this helps and good luck.

Dave C.

 

[cactuscarl]

Thanks for the info! I'll pass it along and find out about the pistons for you.

What's compression on the pistons? Are they new?

-Jeff

 

[bisonmn]

Kanter auto sells the HP pistons. I have heard they may not be a close replica of the originals.

 

[cudax4]

Check with Hensley Racing.Last time I checked they had the high comp. pistons.The Commando cam was .248/.420 lift.I have some cool vintage parts such as an edelbrock dual quad intake & a bunch of other goodies I've been hording.

 

[barracudadave67]

Cactuscarl
Pistons and rings I have for the 273 are new in box. They are for the reg 273 2bbl engine, I think they are 8.5 or 9.0to 1, they are not the hipo ones, sorry.
I didn't know you could still get the hipo ones. Knews to me. Ken at Hensley Racing should know about it tho.
I also have other 273 parts, including a chrome air cleaner, and the black wrinkle finish, finned valve covers.
Dave C.

 

[valiantwagonguy]

You'd probably be better off decking the block & milling the head to get the compression up and using the flat tops. The 2bbl pistons have a negitive deck height and the hi po ones have a positive height so you have lots or room to fool around and everything Ive heard about flat tops vs domed pistons is slanted towards the flat tops.Just my 2 cents