Using 5A CAM on 7A block

[Fred_SPb]

^^

+ rep... and all the way to Russia

Thanks

what's the inlet valve cam measurement, in mm? degrees of cam-shaft duration?

This is a height of camshaft cams in millimeters. You can see - 5A has smaller height than 4A/7A.

and yea 7A-GE having rev problems? did you mean doesn't rev as high and hard as a 4A?

Yes, because 7A has longer conrod (IMHO)

[Sam_Q]

bill are any of the F series heads available in this country that are decent for potential?

[3sgte]

In my previous posts I posted about the differences between the old 4A-FE head and the new 4/7A-FE head.

I have had no luck finding 5A info, but here is some stuff about the new 4/7A-FE head:


and


Looking in through the intake ports, it is just like a motorcycle, you see nothing but the umbrella part of the valves.

[Billzilla]

bill are any of the F series heads available in this country that are decent for potential?

Yeah the twin-port TVIS ones aren't too horrible. They need a lot of work around the bottom of one of the ports though, as Mr Toyota has added some weird swirly thing in there. And one port is smaller than the other as well.

*points up*
Bloody good image there, thanks!

[normality78]

3sgte,
god, you're da man with the image.

billzilla,
what kind of job needed to be done around the bottom of one of the twin-port TVIS? Im having this head/inlet manifold now

[Billzilla]

billzilla,
what kind of job needed to be done around the bottom of one of the twin-port TVIS? Im having this head/inlet manifold now

Quite a lot of grinding to make both ports the same, as they're different to each other in each cylinder. Just one quick look with the valves out and you'll see what I mean.

[normality78]

Billzilla,
currently this is what im trying to do.

stock





after





do you have a sample of pic about the port you've done? Kts

[3sgte]

That's one way to shorten the intake runners.

Edit:
That is the manifold that was used on the good head (later version, labeled new on the pics on the previous page).

Assuming that you have the head without those swirl valves then you have nothing that needs to be done.

(you are running a turbo?)


Bill,

If you are talking about the valve, and it is on a -FE, then I am pretty sure that it is for swirl (lean burn) reasons.

This would (of course) contrast with the TVIS which was intended to effectively vary intake runner length.

Wouldn't it just be easier to start with a 4/7A head that didn't have that valve?

[Billzilla]

Billzilla,
currently this is what im trying to do.


do you have a sample of pic about the port you've done? Kts

I'm not using that inlet manifold, but one that I'm making myself and it'll be rather different.

But for the 7A I'm building in Malaysia, it has to have a stocker (from the outside) manifold so I was stuck with it, and I removed the ribs between the ports as I wanted to get the inlet runners as short as I could and it'd also give a little more volume to the plenum.

[Billzilla]

Bill,

If you are talking about the valve, and it is on a -FE, then I am pretty sure that it is for swirl (lean burn) reasons.

This would (of course) contrast with the TVIS which was intended to effectively vary intake runner length.

Wouldn't it just be easier to start with a 4/7A head that didn't have that valve?

As fate would have it, he is - That's the inlet manifold from the good head.
There's not a lot to be done to those ones on the inlet side as they're extremely good as-is.
But the exhaust could do with a little work and this is what I've done so far ->



I needed some more area in the ports and also to bring the #1 and #4 ports back in-line, as they are offset too much for my liking. Turned out the exact distance I needed to move them was also the exact distance I needed to oval the port to get the area I wanted.

[Sam_Q]

heres another one for you bill: I know this is an impossable question but assuming I use that I got that TVIS head and did some heavy porting, valve de-shrouding, standard cams and ran a 20v intake with a custom manifold and put side by side against a ported blacktop with standard cams how would it fare?

I think next sunday I will pull the intake manifold off that 5A engine and have a look and try and take a picture if I can, it didnt look promising though.

[Billzilla]

heres another one for you bill: I know this is an impossable question but assuming I use that I got that TVIS head and did some heavy porting, valve de-shrouding, standard cams and ran a 20v intake with a custom manifold and put side by side against a ported blacktop with standard cams how would it fare?

I think next sunday I will pull the intake manifold off that 5A engine and have a look and try and take a picture if I can, it didnt look promising though.

The technical expression is that it'd "shit all over the 20v from a great height".
Here's the 248hp engine ->

[Sam_Q]

looks awesome Bill. I am looking into it from the viewpoint of trying to get power with some decent economy on top, I know this is always going to be a compramise but i am trying to get as much of both as I can.

3sgte: could I have a link for that early/late F head comparasin thread?

[Sam_Q]

so its still capable of killing a blacktop even with standard valves and cams? I am going to look more into this

[Billzilla]

so its still capable of killing a blacktop even with standard valves and cams? I am going to look more into this

I'm not sure how big/small the cams are in the FE heads, you may need to organise some bigger sticks.
FWIW the ones I'm using will be about 280deg duration and 0.440" lift.