Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Fri Mar 29, 2024 12:08 am

All times are UTC-07:00




Post new topic  Reply to topic  [ 4 posts ] 
Author Message
PostPosted: Sun Oct 14, 2018 10:23 pm 
Offline
Turbo EFI
User avatar

Joined: Fri Dec 30, 2005 2:49 pm
Posts: 1152
Location: Houston, TX
Car Model:
Well, it turns out I won't have time before the next Lemons race to put together the long-rod engine I'd been planning. Not enough weekends left, too many other things to do, and I want to take my time with the oiling mods on this one.

My backup option is a stock '73 long block with the head from my old race engine (1.70/1.44 valves, ~48cc chambers, mild porting). I haven't measured the deck height yet, but I assume this engine will end up around 8.8 SCR with stock pistons. My question is which camshaft I should use in this engine. Using a Holley 350 on a 2-bbl aluminum intake and Dual Dutra Duals with 2" primaries into a 2.5" pipe. It'll be raced on a road course primarily between 3000-4500 RPM in a ~3100 lb. car with a stock A904 converter and 3.55 gears.

Options:
1. Stock 1973 225 camshaft that's already in it
2. Isky camshaft from the old race motor (single-pattern .448 lift, 264 advertised duration, 109 LSA)
3. OCG 346 regrind that I ordered for the slightly higher-compression long-rod build (not ideal, as I'd either have to pull it out later or order another)

I'm leaning toward snagging the used Isky out of my old engine, but I'm also looking for suggestions on how to degree it. I previously had it slapped in dot-to-dot, but I'm not in that much of a hurry this time around.

_________________
Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing


Top
   
PostPosted: Mon Oct 15, 2018 8:10 am 
Offline
Supercharged
User avatar

Joined: Sat Nov 27, 2004 8:03 pm
Posts: 8977
Location: IRWIN PA
Car Model:
I will let Lou or others will chime in on this one. I don't have words of wisdom in regard to cams - however take into consideration the oil pump gear shredding factor.

If you are endurance racing I might use a known good pump gear / cam gear combo unless you are going to an external pump.


Greg

_________________
http://www.youtube.com/hyperpack
Image


Top
   
PostPosted: Mon Oct 15, 2018 10:40 am 
Offline
Turbo EFI
User avatar

Joined: Fri Dec 30, 2005 2:49 pm
Posts: 1152
Location: Houston, TX
Car Model:
Good point about the pump gears. The '73 block still has a factory aluminum oil pump, so it's probably fine with its existing cam, but I'd have to eyeball the gear and check the rotor clearances at least.

The Isky has been running for years with a cast iron Melling oil pump that I know still makes good pressure, so I'll swap it over if I use that cam.

_________________
Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing


Top
   
PostPosted: Tue Oct 16, 2018 5:12 am 
Offline
Board Sponsor & Moderator
User avatar

Joined: Mon Oct 21, 2002 11:08 am
Posts: 16451
Location: Blacksburg, VA
Car Model:
For that RPM range, use the Isky for sure. Degree it at 100-102. You would make more power overall with the OCG, but at higher RPMs.

Lou

_________________
Home of Slant6-powered fun machines


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 4 posts ] 

All times are UTC-07:00


Who is online

Users browsing this forum: Google [Bot] and 71 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited