Rock Chip wrote:
I have a 1965 318 poly punched to 390 i have the factory dual quad with edey 600s on it and tti headers ported heads reground cam 230ish duration 480 lift 11to1 compression.
What id like to know is it seems to lay down at 5000 to 5500 dont want to rev much past that, I have stock points stock fuel line new stock fuel pump, do ya think I should upgrade to electronic, What timing seems to work best for the old poly
also I thought about puttin a put put pump back by the tank to help fuel delivery.
By the way its in a 1965 Coronet 4dr 727 shift kit slightly looser converter, relocated superstocks 3.91 gear, suregrip 26/10.5" drag radials weight 2660 lbs old porky
ran a best of 14 flat @ 89 to 90 traction not a problem.
Would a Weiand 2 four intake help much other than its lighter.
Any info on drag racing the old poly would greatly be appriciated !!!!
I know thares more in thare I just dont want to spray the sneeze at it yet, "Thats to easy"
I like beating up on the new stuff with the fART CANS and some of the old blow ties and burnt ovals
First a question - how do you get 390 cubic inches out of a 318 Poly block??
It's not possible to just bore the block to get anywhere near that displacement.
390 inches from a 318 - besides boring the block out to the max - would require
a custom-made billet stroker crank out to about 4 inches - which would then also
require custom made pistons and aftermarket custom-length rods. It could be
done, but not without spending in excess of 4 grand or more just for the rotating
That aside, about the engine laying down at around 5500 rpm. It's almost certainly
running out of fuel. Even a new stock fuel pump is not adequate to maintain enough
flow and pressure under load at 5000-plus rpm. At the very least, you need an electric
pump at the back of the car, mounted down low and near the tank and running through
at least 3/8 diameter fuel line up to the existing mechanical pump on the engine.
Don't forget the suction side of the pump either. The suction line feeding the rear
mounted electric pump should also be at least 3/8 diameter (and preferably
bigger) and draw from a fabricated external sump in the bottom of the tank,
rather than through the stock fuel pick-up.
If you've already got the factory dual-quad intake, other than a few lbs. of weight
there's probably not much advantage to a Weiand dual-quad intake. Where would
you get one anyway? Weiand doesn't make one for the 318 Poly. They might have,
40-odd years ago, maybe, but certainly not currently. Weiand still makes one for
the 331-354-392 hemis, but that won't fit your block or heads. Offenhauser *might*
still offer one for the 318 Poly, but even that is a long shot. If you're looking on
ebay or the swapmeets etc for an intake - or other "Poly" parts for your engine
- be aware that the 318 Poly was originally a Plymouth engine and totally different
from the 315-325 Dodge and 301-331-354 Chrysler Polys and almost nothing
The rest of your set up - if you're turning beyond 5000 rpm , definitely get rid
of the points and use some sort of electronic conversion. An MSD6 box along
with premium quality wires cap and rotor would all help too. Also make sure that
your valve springs are up to the task and are compatible with the cam you're
using. Stock valve springs, even when new, won't cut it much beyond 5000- 5500
rpm and they weren't made for anywhere near .480 valve lift either. Everything
in the valve train needs to be right. Installed valve height, clearance between
the valve spring coils at full lift, pushrod length, rocker arm geometry etc all
need to be checked and made right if you're gonna' twist the engine. Good luck!
P.S You asked a straight tecnical question so I gave you a straight anwer,
but there's several details in your post - besides your supposed and impossible
"318 punched out to 390" that don't quite add up. First, a '65 Coronet 4-door
weighs in at a heck of lot more than 2660 lbs. Try maybe 3660???.3400 at least
as a bare minimum. Secondly if you're running 14 seconds flat, you should be
turning a lot more tham 89 -90 mph. A 14 flat e.t. should put you through the l
ights at closer to 97 or 98 mph...And you did say youre running 10.5 inch slicks
so your not not having traction problems,. right?? Aren't you also the guy that
recently scored a set of Kieth Black aluminum Hemi heads - and then about the
same time, also bought a pair of super rare factory D5 race heads as well??
Hmm?? Methinks maybe this car of yours is more in your mind than anywhere else!