safe revs for ej22t

[c32b]

hi, looking to know what is a safe limit to rev my ej22t to? going to fit some 256 deg cams and looking to rev to around 7500. Would it be too much to ask from this engine? do advise please.

[georryan]

Take everything I have to say with a grain of salt, but.....

From what I can REMEMBER from reading posts about the EJ22T and it being used by other people like Xypher, the valves tend to float when reved that high, but you can put in some stiffer valve springs. I think with the stiffer valve springs the heads were ok to be reved up to 7500. Remember that our heads are not the most free flowing. They were built to make power in the low to mid range. So, although you may rev that high, you'd see better results with something that flows more freely. I recall something about a post where the heads were bored out to some good effect, but there was a sacrifice in some torque down low.

Here's a quote:

Anyways, you are correct in assuming the heads aren't stock. They EXTREMELY ported and polished, aftermarket valves, three angle valve job, dual valve springs, and titanium retainers. At one point I had bigger cams. They were from the same place that does Cobb's cams. Those cams aren't in the heads now because they disintegrated. Yes, you heard that right. The welds on the lobes started eroding off after several months, and one of the lobes actually chipped and popped a shim out and caused catastrophic damage to the head. It took a long time to fix that mess. I concluded the welded cams might not have been hard enough to withstand my super stiff valve springs.

While I was repairing those heads, I tried a set of stock heads with stock cams, and was pleasantly surprised. THE STOCK HEADS WORK VERY WELL. Don't get me wrong, there are noticable differences, but not how you would think. With the stock heads, there is a significantly crisper and responsive low and mid range. With the ported heads there is a MUCH better top end (after 5000 rpm), but the mid range suffers, and the low end response really suffers.

With the ported heads and stock cams, I hardly noticed a difference without the bigger cams. After you get to a certain HP level, it becomes difficult to distinguish an extra 10-15 HP. It did seem however that the stock cams gave me a more tolerable low end with the ported heads.

Currently, I'm using the ported heads(mostly because I already have them) with the stock cams. If I had to do it over again, I would have left the heads alone, with the exception of upgrading to stiffer valve springs (valve float occurs around 6500-7000 with high boost).

As far as engine management, I'm using the LINK Plus. It works really well for me, although it seems some people can't get it to work for them.

Graham -
1.I'm using the stock cam. The rev range has more to do with the turbo size than cams. Cam selection appears more critical with NA engines. On an older smaller turbo, I noticed my revs maxed out around 6500-7000. I went to the bigger cams and ported heads to fix that problem, and ended up with minimal gains. However, with the bigger turbo, my rev range jumped right up to 8000.

Here's the link:

http://bbs.legacycentral.org/viewtopic. ... ve+springs

[c32b]

Take everything I have to say with a grain of salt, but.....

From what I can REMEMBER from reading posts about the EJ22T and it being used by other people like Xypher, the valves tend to float when reved that high, but you can put in some stiffer valve springs. I think with the stiffer valve springs the heads were ok to be reved up to 7500. Remember that our heads are not the most free flowing. They were built to make power in the low to mid range. So, although you may rev that high, you'd see better results with something that flows more freely. I recall something about a post where the heads were bored out to some good effect, but there was a sacrifice in some torque down low.

Here's a quote:

Anyways, you are correct in assuming the heads aren't stock. They EXTREMELY ported and polished, aftermarket valves, three angle valve job, dual valve springs, and titanium retainers. At one point I had bigger cams. They were from the same place that does Cobb's cams. Those cams aren't in the heads now because they disintegrated. Yes, you heard that right. The welds on the lobes started eroding off after several months, and one of the lobes actually chipped and popped a shim out and caused catastrophic damage to the head. It took a long time to fix that mess. I concluded the welded cams might not have been hard enough to withstand my super stiff valve springs.

While I was repairing those heads, I tried a set of stock heads with stock cams, and was pleasantly surprised. THE STOCK HEADS WORK VERY WELL. Don't get me wrong, there are noticable differences, but not how you would think. With the stock heads, there is a significantly crisper and responsive low and mid range. With the ported heads there is a MUCH better top end (after 5000 rpm), but the mid range suffers, and the low end response really suffers.

With the ported heads and stock cams, I hardly noticed a difference without the bigger cams. After you get to a certain HP level, it becomes difficult to distinguish an extra 10-15 HP. It did seem however that the stock cams gave me a more tolerable low end with the ported heads.

Currently, I'm using the ported heads(mostly because I already have them) with the stock cams. If I had to do it over again, I would have left the heads alone, with the exception of upgrading to stiffer valve springs (valve float occurs around 6500-7000 with high boost).

As far as engine management, I'm using the LINK Plus. It works really well for me, although it seems some people can't get it to work for them.

Graham -
1.I'm using the stock cam. The rev range has more to do with the turbo size than cams. Cam selection appears more critical with NA engines. On an older smaller turbo, I noticed my revs maxed out around 6500-7000. I went to the bigger cams and ported heads to fix that problem, and ended up with minimal gains. However, with the bigger turbo, my rev range jumped right up to 8000.

Here's the link:

http://bbs.legacycentral.org/viewtopic. ... ve+springs

hi, thanks for the comment. forgot to mention that i'm on a wrx ver 4 head. will this change my possible revvability? boost wise i dont think i will exceed 1.4-1.5 bar worried about either valve float or spinning a bearing.

[georryan]

Having a 2.0 head on a 2.2 block? I forgot how that affects your compression ratio, but you have to take that into account. High compression ratios and high boost are a bad idea. Things tend to go boom if you aren't real careful.

I think the ej20 heads lower your compression.

http://bbs.legacycentral.org/viewtopic. ... ight=heads

That link might be helpful.

Also, if you are going to run that kind of boost, you'll need some sort of aftermarket engine management. As long as you have good air/fuel ratios, oil pressure, and your valves aren't floating you'll probably be alright. Having the 2.0 heads, which I think already reved to 7500 should set you in the right spot. I doubt you'd need to upgrade the valve springs on those heads.

[c32b]

Having a 2.0 head on a 2.2 block? I forgot how that affects your compression ratio, but you have to take that into account. High compression ratios and high boost are a bad idea. Things tend to go boom if you aren't real careful.

I think the ej20 heads lower your compression.

http://bbs.legacycentral.org/viewtopic. ... ight=heads

That link might be helpful.

Also, if you are going to run that kind of boost, you'll need some sort of aftermarket engine management. As long as you have good air/fuel ratios, oil pressure, and your valves aren't floating you'll probably be alright. Having the 2.0 heads, which I think already reved to 7500 should set you in the right spot. I doubt you'd need to upgrade the valve springs on those heads.

I have forged pistons so perhaps it comes up to about 8.5:1 according to the specs. i am planning to keep it about 7500 rpms tops when i'm stretching it but 7000 at most on regular occasions. luckily i do have a standalone computer.

[Matt Monson]

Which heads you have on there have everything to do with where you can rev to. The stock Ej22T heads really don't like to go above 7000+/-rpms. The reason for this has nothing to do with valves, but has to do with the fact that it uses HLA's to regulate valve lash. Much above 7000, the hla's can't recover between rotations and start to get loose and slap.

If it's a standard v4 WRX head it will be almost identical to the DOHC Ej25 heads that Xephyr used to use (He NEVER used Ej22T heads in his car). Running them up to 7500rpm is really the limit on those heads. The reason again has to do with valve actuation. Those heads use a shim over bucket design and above 7500 rpms they are known to spit shims. But if you run a 7500rpm redline and generally shift at 7300-7400 I wouldn't worry about it...

[c32b]

Which heads you have on there have everything to do with where you can rev to. The stock Ej22T heads really don't like to go above 7000+/-rpms. The reason for this has nothing to do with valves, but has to do with the fact that it uses HLA's to regulate valve lash. Much above 7000, the hla's can't recover between rotations and start to get loose and slap.

If it's a standard v4 WRX head it will be almost identical to the DOHC Ej25 heads that Xephyr used to use (He NEVER used Ej22T heads in his car). Running them up to 7500rpm is really the limit on those heads. The reason again has to do with valve actuation. Those heads use a shim over bucket design and above 7500 rpms they are known to spit shims. But if you run a 7500rpm redline and generally shift at 7300-7400 I wouldn't worry about it...

thanks. mine is a near standard v4 rex head. i was thinking of tuning for 7.5k rpm just for some flexibility and shifting mostly at 7.2 or so. would run some sti cams 256 duration to just improve the upper powerband but nothing too mad. not so familiar with the rex head as i've just owned for a short time so appreciate the invaluable tech help.

[Matt Monson]

you'll be fine doing what you want to do. Just make sure that someone who knows those heads well adjusts or helps you adjust the lash once you get the new cams. It will require new shims pretty much on every valve...

[206er]

anyone know what kind of rpm the bottom end can handle before the rods let go? just wondering.

[c32b]

you'll be fine doing what you want to do. Just make sure that someone who knows those heads well adjusts or helps you adjust the lash once you get the new cams. It will require new shims pretty much on every valve...

thanks mate! i'm just hoping to get that 4800-7500 to some sweet torque with some nice cams soon so hoping the head will hold up. aiming for a td05 20g too for a better efficiency