Open Chamber or Semi-closed Chamber ?

[Brien]

I've the choice of using an open chamber 62cc head or
a semi-closed 'D' chamber 74cc chamber on an Inline
258 6 EFI Turbo I'm building .

What are the Pros' / Cons with each ?

6" to 6.125" connecting rods avail.

This is a Street Summer Daily Driver -
6lbs. Boost = 275HP

I'd like 300 to 350 on Demand .

Thanks in Advanced !

:SHOCKED:

[Sixgun86gn]

It is beleived that a closed chamber and dished pistons make a better flame front for power.

[KendallF]

I've the choice of using an open chamber 62cc head or
a semi-closed 'D' chamber 74cc chamber on an Inline
258 6 EFI Turbo I'm building .

What are the Pros' / Cons with each ?

6" to 6.125" connecting rods avail.

This is a Street Summer Daily Driver -
6lbs. Boost = 275HP

I'd like 300 to 350 on Demand .

Thanks in Advanced !

:SHOCKED:

The best one will be the one that promotes the best flame travel, and that usually will be the closed chamber head, as long as you can get a piston dish to match. Are there significant flow differences between the two heads?

258...Is this an AMC motor? Sounds like an interesting project. :) Pics or details?

[Brien]

The best one will be the one that promotes the best flame travel, and that usually will be the closed chamber head, as long as you can get a piston dish to match. Are there significant flow differences between the two heads?

258...Is this an AMC motor? Sounds like an interesting project. :) Pics or details?

Hello Kendallf!

!Yes - AMC!

Wonering if I can run roller lifters &
Combustion Chamber shape was a question :

http://members.tripod.com/~Mojo_Page/Headpg1.htm

The up to 1986 258 can run early heads & the newer 4.0 .

I can stuff the 12 counterweight 258 crankshaft into the
newer 4.0 block - along with stronger main caps - and
have a 4.5 Litre .

4.0 has the 'newer' combustion chamber and the ''Raised Port'
design - but ports themselves are 'tiny' in stock form (see 'Mojo' .jpgs on site)

These .jpgs are off : Strokers@yahoogroups.com

Shiney head is a late model 4.0
Used head is a 258 semi closed chamber .

Shiney pistons are Venolia .

Found a Turbo from a Chevy 'Typhoon' - any good ?

:essen: