DOHC Install - does swapping cams require valve adjustment?

Heads, valves, pistons, rods, crankshaft, etc...

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wtdash
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DOHC Install - does swapping cams require valve adjustment?

Post by wtdash »

Edit: Quick answer= YES

EJ22T with '98 EJ25 DOHC heads (shimmed bucket lifters) running EJ20K turbo camshafts.

When I swap in the EJ25 stock cams do I need to re-adjust the valves?

They were recently adjusted when I had the heads done w/the turbo cams for the swap (have less than 2500 miles on 'em).


History: Car is slower than ever off the line (yes, even slower than the stock EJ22T w/SOHC heads), which is most likely due to the low 7.5:1 CR I'm now enjoying w/the stock EJ22T head gasket. Before I go to the trouble of swapping the HG to a thinner one, I thought I'd try swapping the cams. I've read online that the EJ20K cams are more for HP/RPMs than Torque. Read POST#20. My original thought process was, "I have a DOHC turbo, I should use turbo cams."....notsomuch?


Thanks
Td
Last edited by wtdash on Fri Jul 15, 2011 11:40 pm, edited 4 times in total.
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
Legacy777
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Re: DOHC Install - does swapping cams require valve adjustme

Post by Legacy777 »

Do the DOHC heads you're using have mechanical or hydraulic lifters? If they're mechanical, they should be readjusted.
Josh

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1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

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wtdash
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Joined: Fri May 04, 2007 4:09 pm
Location: N. ID

Re: DOHC Install - does swapping cams require valve adjustme

Post by wtdash »

Shimmed bucket lifters, per Wikipedia...damn! Those shims are PITA to get the right ones, and supposedly there is a special Subaru tool to hold the bucket while replacing the shim.....otherwise the engine has to come out to do it correctly. Double Damn!

I'm getting an updated 'Rob tune' EJ20G chip w/more timing advance...Hoping that helps.

Td
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
wtdash
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Posts: 2349
Joined: Fri May 04, 2007 4:09 pm
Location: N. ID

Re: DOHC Install - does swapping cams require valve adjustme

Post by wtdash »

According to a well-respected member on here, Matt Monson, in response to changing cams:
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...
Td
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
MikeyMeyagi
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Re: DOHC Install - does swapping cams require valve adjustme

Post by MikeyMeyagi »

shouldnt be slow, urabusturbo on here is still running a stock 22t ecu with that same motor setup and a vf34 and he made about 220whp on 14psi.

i have the turbo cams in my engine and it was a upgrade from the n/a cams for sure
94 Supra Turbo 6 speed. build in progress
98 Lexus GS300, single turbo 2JZGTE swap. daily driver
93 Impreza wagon, home brewed n/a-t ken block themed winter drift missle

*sold*
94 Alpine Sport Wagon... STi conversion, rotated turbo etc
wtdash
Fifth Gear
Posts: 2349
Joined: Fri May 04, 2007 4:09 pm
Location: N. ID

Re: DOHC Install - does swapping cams require valve adjustme

Post by wtdash »

^Slow off boost.....but still doesn't hit as hard it should on boost either.


Thanks,
TD
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
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