I wanna re-build an engine for my I6.

The engine that is in the car at the moment is a hybrid, i.e.: post 1/98

From what I can decipher, almost any I6 from an EL will do, however the dilemma I am in is as follows:

The EF has large intake ports in the heads, which equates to high revs/hightorque/ power.

The EL "hybrid" has smaller intake ports, which equals more torque @ lower revs. I justify this by the use of the intake "tongues" used by Cleveland 4V owners to create the torque obtained by Cleveland 2V owners.

Which direction should I go? What I want is grunt as low as possible, as I will be towing. I rarely rev over 3000 if I can help it.

I was brought up on a 351 Cleveland, and probably expect the same from an I6, but I know it cannot happen

What should I do?
1) develop an early model EL motor ( basically an EF motor, large ports, straight valve springs, smaller big ends, long rocker ratio)

OR

2) develop a late EL motor ( smaller ports, shorter rocker ratio, larger exhaust valves )

Any (sane) comments will help

are you willing to loose topend to have heaps down low?
or do you want more down low and try to retain the peak power aswell?

I am happy to lose top end to have heaps down low. I never use the top end, the most I like to rev to is maybe 3000 odd. I have only really used the availab;e top end when coming onto the freeway from the Macas at Calder

CLEVELAND PORTS were always too big!

yes believe it or not...they were too big and caused way too much turbulance...even for top end power that people started to use 302 heads!

my old mans 351 has 302 heads, and was the best thing weve ever done on it...even though the cams made for mid-high end rpm

Yep, that's right, I had 302 heads on my 351, which were machined to reduce the compression ratio. But it was the small inlet ports/smaller valves which did the trick, it would go into top gear at 40kph and just stay there, no matter what i did, it would just pulled itself out of anything, anywhere!! Grunt plus!!

if thats the case and you stick with the hybrid engine. you need to use an cam for the 1.8 rockers. the crowcams 2232526 has power from 900rpm to 3500rpm.

leave the ports standard but aim for about 9.8:1 compression
use an AU head gasket to close up the piston to head clearnce, this helps to reduce the likelyhood of knock.

go for the biggest over bore you can. i'm pretty sure that 40thou

find a set headers with very small primary pipes. and dont go for the usual 2.5 inch exhaust. a good mendrel bent 2 1/4 or even 2 inch system would suit what you want.

you may even want to go as far as making up an inch spacer plate for the intake manifold/head and a half inch spacer for the split in the bbm.
the longer intake will help with torque. that is if you are chasing all you can get.

that is excellent information tickford_6. I understand all but the "bbm" bit

What you are saying is to fabricate a plate to go between the intake runners and the head?

The zorst is interesting. I have headers (pacemakers), but they don't seem to do a lot below 3000 odd. I am currently running a 2"i.d (I think) I can actually feel the difference when accelerating over 2500. I actualy think that when I had the zorst fitted. I lost power low down

I want as much grunt as I can get.

I am currently using the recommended Crow cam for the hybrid

This is good stuff (more please)

BTW it is running on LPG, ( Gasresearch carby)

aahhh, bbm = the split between the short and long runners???

the intake manifold splits in half. if you put a half inch spacer plate in there it will give extra length to the short runners.

if you put a spacer between the head and the manifold it will give extra length to both the long and the short...

on gas you could go up a little more with the compression

install aluminium pistons (flat tops) and COMRESSION, COMPRESSION, COMPRESSION

bring it up to 12:1 and a water injection system for 1 gran brand new.....with this set up, u can haul a SEMITRAILER! those torque figures would be CRAZY!!!

maybe I should just turbo the bloody thing and be done with it. should be able to do that for 3k? fitting it myself

be better of with an eaton blower.. no waiting for boost

I think turbo would be better. Ford looked at supercharging for the BA i believe, but for some reason I can't remember, they rejected it, and turbo'd instead. I think it was something to do with the distances beween the pulleys