4EFE vs 4EFTE engine block differences for forged engine build.

[aubreygil]

 

[Djaniero]

Just a quick one guys. Finally got around to stripping my 4efe today in prep for forging. As a few people said, the crank is the same as the GT crank and marked 4ET

 

[Frankieflowers]

Just a quick one guys. Finally got around to stripping my 4efe today in prep for forging. As a few people said, the crank is the same as the GT crank and marked 4ET

Great news!



!

 

[Djaniero]

Thanks @Frankieflowers . How are you getting on with your build?

 

[Frankieflowers]

Thanks @Frankieflowers . How are you getting on with your build?

The engine block and head is at the machine shop since December waiting for the Pistons. I finally received the pistons, and I also bought the optated springs with titanium retainers from the US. One piece at a time as every of these parts is very expensive.
The next step will be to buy ACL bearings ans ARP headbolts. Even if the machine shop told me, he doesn’t like the idea to machine the head to fit the bolts for the head studs, I still haven’t decided if I want to insist or just buy headbolts i’m telling this, because the strength of the engine would be different which means it would limit its power to max 350 hp I guess…
if I think about the money I invested in this project I don’t want to limit the project itself just because of a few hundred euros extra.
Camp Dogs In Australia are clear about that. You will keep the head down wit head studs.
If you think about my current engine, that is completely stock, besides a higher compression due to 2 decimeters shimmed on the head with a stock 1.2 mm headgasket, I run 206 hp at 1.1 bar with a hybrid ct9 with ct12 internals and Ergal blades. Spoont is at 2500 RPM.and turbo lag is practically zero. The forged engine will require a new exhaust manifold with a.Garrett 2867. Let’s not forget that I will have to buy coil on plugs together with a Link MonssonX or AtomX ECU. Around €500 euros…
I would like to talk to someone who did drill the head for the 10.5 mm studs to understand if it is really worth it.

 

[Frankieflowers]

I wouldn't worry too much about the conrods. Yes they are cheap and you can spend x3 as much on different ones.

But any forged conrod is not the weak link in a 4e engine.

Matty_gt runs the maxspeeding conrods at 370+ bhp.

Hi mate. Do you suggest using ARP 10.5 mm head studs or keeping head bolts? My machine shop doesn’t feel comfortable drilling the space for the head nuts between valves.

 

[Djaniero]

The engine block and head is at the machine shop since December waiting for the Pistons. I finally received the pistons, and I also bought the optated springs with titanium retainers from the US. One piece at a time as every of these parts is very expensive.
The next step will be to buy ACL bearings ans ARP headbolts. Even if the machine shop told me, he doesn’t like the idea to machine the head to fit the bolts for the head studs, I still haven’t decided if I want to insist or just buy headbolts i’m telling this, because the strength of the engine would be different which means it would limit its power to max 350 hp I guess…
if I think about the money I invested in this project I don’t want to limit the project itself just because of a few hundred euros extra.
Camp Dogs In Australia are clear about that. You will keep the head down wit head studs.
If you think about my current engine, that is completely stock, besides a higher compression due to 2 decimeters shimmed on the head with a stock 1.2 mm headgasket, I run 206 hp at 1.1 bar with a hybrid ct9 with ct12 internals and Ergal blades. Spoont is at 2500 RPM.and turbo lag is practically zero. The forged engine will require a new exhaust manifold with a.Garrett 2867. Let’s not forget that I will have to buy coil on plugs together with a Link MonssonX or AtomX ECU. Around €500 euros…
I would like to talk to someone who did drill the head for the 10.5 mm studs to understand if it is really worth it.

Sounds like it’s going to be a beast once it’s all finished.
I opted to just stick with the just head bolts as my power goals are 300. I would push for more but I don’t want my gearbox to die.
Camp dogs does use the studs but again his engines produce a lot more power.

will you be having your crank balanced also?

 

[daniel_g]

Hi mate. Do you suggest using ARP 10.5 mm head studs or keeping head bolts? My machine shop doesn’t feel comfortable drilling the space for the head nuts between valves.

Here is a cyclinder head that I had modified for head studs fitment.

You need some area buffed away with a dremel to allow room for the nut and also the socket to torque the nut.

I would insit that this be carried out.

The ARP studs do offer a greater clamping force.

 

[Frankieflowers]

Sounds like it’s going to be a beast once it’s all finished.
I opted to just stick with the just head bolts as my power goals are 300. I would push for more but I don’t want my gearbox to die.
Camp dogs does use the studs but again his engines produce a lot more power.

will you be having your crank balanced also?

Excellent point. We don’t want to destroy our gearbox. To be honest, I don’t think that vJUS gearbox can handle comfortably more than 250 hp. They do, but they don’t last long. They are impossible to find…

 

[Frankieflowers]

Here is a cyclinder head that I had modified for head studs fitment.

You need some area buffed away with a dremel to allow room for the nut and also the socket to torque the nut.

I would insit that this be carried out.

The ARP studs do offer a greater clamping force.

Thank you very much. I will show him these pics.

 

[gorganl2000]

i prefer the ARP head bolts...they may not facilitate the maximum potential power like the studs will, but the head bolts are a direct fit and allow decent power/boost anyways

i don't like the additional dremel/shaving work required to fit the studs, particularly on a "daily" vehicle---if it was for an all out track/drag/race car, then ok

 

[Frankieflowers]

i prefer the ARP head bolts...they may not facilitate the maximum potential power like the studs will, but the head bolts are a direct fit and allow decent power/boost anyways

i don't like the additional dremel/shaving work required to fit the studs, particularly on a "daily" vehicle---if it was for an all out track/drag/race car, then ok

The good thing about the Mazda Miata head is that is has head studs as a default setup. There os a engine forged assembly on youtube about it. The engine is very similar to the 4efe/fte

 

[Frankieflowers]

will you be having your crank balanced also?

Hey sorry I missed it. Yes I will def get the crank checked and the cams cleaned. I’ll let the shop take care pf the head assembly with the new valve springs. I will assemble the block. Can’t wait!