DeTomaso Mailing List: February 98, Message #89
     



From: 	MikeLDrew@aol.com

Subject: Re: L-Model Power

Date: 	Mon, 2 Feb 1998 18:27:51 +0000



Ted wrote:



>...so basically to get "scare-the-pedestrian" horsepower out of an L-model

block you need different heads?-I fix computers so excuse the question if

it sounds lame-



>>>Not lame at all!  Perfectly reasonable question.



Clevelands originally came with closed-chamber 'quench' cylinder heads, early

'71's were 11.0:1 compression, later '71's and early '72's were 10.0:1, then

mid '72 (before the L-model came out, by the way) open-chamber cylinder heads

were introduced, it dropped to 8.9:1 and horsepower went down from 310 to 264

or thereabouts.



I think the early '71's used pop-up pistons, and then the rest  all used the

same, flat-top pistons, but I'm not sure, anyone care to verify?  Presumably

you can get your compression (and thus horsepower) back by installing a set

of closed-chamber heads; alternately, you can fit domed 'pop-up' pistons with

open chamber heads.  This latter combo is what I have on my car, only because

that's what was on it when I bought it.



Personally, if I was going to invest in a new set of heads, and go through

all the hassle of R&R'ing the top half of my motor, I'd probably go whole hog

and spring for a set of Australian 2V heads, which really are The Hot Ticket

(although admittedly more pricey as well.)



One question I've never heard a good answer to:  What sort of intake manifold

must you run when using Aussie heads?  Since they have 2V ports, do you run a

2V manifold?  (Edelbrock makes a 2V version of the Performer, I don't know of

any others out there.)



Plenty of Aussie head knowledge on The List; let's hear it! :>)



Mike