1FZ-FE Engine Build Questions for a FJ40 (1 Viewer)

[SNLC]

Y’all need to consider just how tight you plan to turn your 1fz.

Stock redline (on an 80 tach) is 5,000 rpm.
Stock displacement is a touch under 4.5l (4476.78cc or 237.19 in^3)

Assuming a VE of 0.8, that’s 9000l/min or about 318 cfm. This is the intake volume.

Straight exhaust tube flows about 115 CFM per square inch. 2.0” 16ga tube will flow about … 318 cfm. 2.5” will flow a bit over 500 cfm. This is more than enough to accommodate the mass of the (burnt and unburnt) fuel and the expansion of the exhaust due to increased temp.

Yes, getting the exhaust tube diameter and primary length can improve scavenging and therefore VE.

Yes, a bit of porting will improve VE.

Yes, forced induction will definitely improve VE.

That fzj40 above is running about 4.7psi of boost, and it was definitely running at sea level in that video (Cartagena, Colombia). Atmospheric pressure at sea level is 14.7 psi, so the supercharger increased the intake volume by about 32% before accounting for the increased intake air temp, but even a 25% increase in effective displacement is HUGE, VE goes up because you’re no longer counting on vacuum to fill the cylinder.

Take a 5.2L stroker, turn it to 6,500 and get the VE up to 1.0 and the intake volume goes to nearly 17,000l/min or 600cfm, and now you’re looking at a 3.0” exhaust, minimum, otherwise back-pressure will rise and VE will drop, so torque drops. So now you run dual exhaust so only half the displacement is in each tube.

I get the race tractor thing. I really do. It’s fun.

But if it’s a daily driver, you’re also unlikely to spending a lot of time anywhere near 5,000 rpm.

You should build a super charged turbo engine, 1FZ or 1HDx variety.

I had one, boost from idle from the SC then compound once the turbo began to spool.

The sound of this (mine was a diesel) is beyond good.

Cheers

 

[estoltman]

Thanks!

I'm not planning on stroking it. I will go 1mm or more over.

I don't intend to rock crawl or race around; just drive it on the road and then overland/camping. However, I am thinking about making the engine super stout with forged pistons and the correct rods. That way if I ever put a supercharger or turbo on it, it's ready.

Good info on the exhaust.

I believe stock compression is 8.5:1. If i was going to bump it, and not get too crazy, would 9 or 9.5 be a good target? And would that change if I ever think I might super charge or turbo it?

 

[estoltman]

What are the OEM injectors good for in terms of HP/torque? Is the OEM fuel pump PSI sufficient as well?

On the ignition, I think I'm going to stay with the distributor setup. I can convert to coil-on-plug later if I want and cap the distributor with a billet cap; just use it for the pickup sensors. I'd looked at what it would take to fit a crank and cam sensor, but not sure if the extra work/cost is worth it. A friend said I could get more accurate timing adjustment. The crank sensor conversion looks pretty straight forward; not clear about the cam position conversion. What are folks thoughts on this? Just leave stock and make sure everything is a 100%?

I also looked at the Kelford (225A) and Crower (stage 2) cams - specs below. Thoughts on these cams? Assuming I open up the chambers and increase the valve diameters? And get new custom pistons matched to the increased head CC?

 

[inkpot]

It's all about Intended Use. Realistically, how and where your going to drive it. Sounds like you already have a USA 1FZFE. Just stock in a light weight fj40 it will be much quicker/stronger. It will smoke the tires easily. We have a 78 fj40 with a 2fe setup at the shop. It will run 80+ on the freeway, but that tall, short wheelbase is not fun to drive at that speed. Seems like overkill to overpower what you can actually enjoy. Does sound like a fun project.

 

[mudgudgeon]

What are the OEM injectors good for in terms of HP/torque? Is the OEM fuel pump PSI sufficient as well?

On the ignition, I think I'm going to stay with the distributor setup. I can convert to coil-on-plug later if I want and cap the distributor with a billet cap; just use it for the pickup sensors. I'd looked at what it would take to fit a crank and cam sensor, but not sure if the extra work/cost is worth it. A friend said I could get more accurate timing adjustment. The crank sensor conversion looks pretty straight forward; not clear about the cam position conversion. What are folks thoughts on this? Just leave stock and make sure everything is a 100%?

I also looked at the Kelford (225A) and Crower (stage 2) cams - specs below. Thoughts on these cams? Assuming I open up the chambers and increase the valve diameters? And get new custom pistons matched to the increased head CC? View attachment 3331851View attachment 3331852

If you can debase yourself enough to visit Facebook, there's loads of technical info hidden in the dribble in the Aussie based turbo 1fz-fe farcebook group.

There's some very knowledgeable people in the group, and good info. Just takes some digging.



For the cam sensor, the older heads aren't drilled and tapped for the sensor. I think it would take a bit of machining to get location and clearances right for that.
I think the older cams have a nub on them for the hall effect sensor. Not sure they do in the early models though.

 

[inkpot]

I have the TRD supercharger with a 2.8" drive pulley. I am running Landtanks MAF and injector setup. I am still running the original OEM fuel pump. I run it up pretty close to redline every nite getting onto the freeway. I do not feel any lack of fuel up past 5000rpm.

 

[gonzopancho]

Thanks!

I'm not planning on stroking it. I will go 1mm or more over.

I wouldn't buy the parts at a stock stroke. Without the additional displacement, the biggest advantage is the savings in reciprocating / rotating weight. That lets things rev quicker and you can turn the engine to higher RPM, at least until you float the valves. But it's a big spend for the parts (and even more to get into the clearancing for a longer stroke.)

I don't intend to rock crawl or race around; just drive it on the road and then overland/camping.

Same, really, at least for the supercharged 1fz-fe out of a 105 in the 1972 FJ40, and the stroked 5.2L for the 1966 FJ45LV. More fishing than camping, because I have a troopy for overlanding.

The 88 FJ62 on an 80 frame with the big turbo... that's definitely a Saturday Night truck.

However, I am thinking about making the engine super stout with forged pistons and the correct rods. That way if I ever put a supercharger or turbo on it, it's ready.

It's ready now. pull the head, do a quality valve job, fit a cometic gasket and ARP head studs and you're ready.

Good info on the exhaust.

I believe stock compression is 8.5:1. If i was going to bump it, and not get too crazy, would 9 or 9.5 be a good target? And would that change if I ever think I might super charge or turbo it?

I have to run 92/93 octane with the stock compression and a stock (NIB) supercharger. The engine has a Haltech on it, but that and the supercharger are really the only mods. The timing is set a little aggressive. It'a a MY98-up 1fz-fe, so the CR might be a bit higher than 8.5:1.

I have a US-model 1fz-fe with ARP studs and a Cometic gasket going into a FJ55. It has a Wits-End turbo on it, and will also have a Haltech.