LSJ vs L61 head PICTURES - Performance Forum

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LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 5:55 PM
does the LSJ head work on an L61 block??

here's your answer....

LSJ head


L61 head


LSJ has a spot for powersteering (not used on cobalt, blocked off with a removable plate) and another spot for for the cobalts cam sensor, not used on Jbody)


L61 only has one


the above two pictures is also why the Lsj and L61 valve covers are not interchangable... if it wasn't for that extra hump both would interchange very easily.


LSJ intake ports


L61 intake ports. note the PCV vent hole is moved (between #2 and #3 cylinders)


whats that mean? jbody manifolds don't work on the LSJ head...


that hole needs to be plumbe into the intake manifold behind the throttle body. some tap work with a metric to -an fitting could do the trick.
another solution would be to use the saab 9-3 turbo manifold... this would work perfectly for this hole...


!!!!the saab manifold I had however will NOT work because I drilled it for the jbody PCV!!!!! (in case you have it and are reading this)

but a new saab manifold will work fine.

L61 cams in the LSJ head also will not work...

the exhaust cam is too short

...

the hole here could be filled with a sawed off cam journal so you don't have a critcial loss in oil pressure... or you can use an LSJ exhaust cam (not very wise unless you're boosted since timings are different)


the temperature sensor for the LSJ is mounted by the upper rad hose...


its on the backside of the block on the L61 so nothing is here..


the structure of the head of the L61...


structure of the head on the LSJ.. you can see slight differences, as well as the smooth casting of the LSJ vs the styrofoam look of the L61


where the EGR would be on an LSJ


where the EGR USED to be on the L61 (i cut it off)


stock picture for reference...


LSJ exhaust ports.. much more meat for port jobs


L61 has very large holes directly beneath the #2 and #3 cylinders so port jobs have to be done carefully, and more conservaitvely.


and finally the block mating surface..

as you see there's little difference between the two other than a few changes in waterjacket shape but otherwise the block is completely compatible.










Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 6:05 PM
do it, can't wait to see what you have up your sleeve for the build man. best of luck.




Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 6:10 PM
very nice write up pj. very informative. thank you



Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 6:13 PM
well since the other thread was junk id like to say again thanks, we need these types of posts here, they are very helpful and just a great reference. thanks peej



Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 6:28 PM
np guys


i do plan on figuring a way to make the lsj head with our plastic manifolds work... just give me some time.






Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 6:41 PM
Not sure what manifold he used but Suncavi used a LSJ head on a L61.



FU Tuning



Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 8:33 PM
John Higgins wrote:Not sure what manifold he used but Suncavi used a LSJ head on a L61.


he made a custom intake manifold out of a veilside DSM Intake manifold



LE61T PTE6262 Powered

Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 8:37 PM
Sheetmetal manifold ftw!!!


Re: LSJ vs L61 head PICTURES
Tuesday, October 16, 2007 10:44 PM
Lots of good pics and info here.... bravo.

Yes, Suncavi already did this swap. I think though (as far as I remember) he is back to the ecotec head again.




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Re: LSJ vs L61 head PICTURES
Wednesday, October 17, 2007 12:10 AM
Sweet write up PJ!! Very detailed



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Re: LSJ vs L61 head PICTURES
Wednesday, October 17, 2007 3:00 AM
I've said it before, and I'm sure I'll say it again PJ for the win. I'm not even an Ecotec guy and I just learned a hell of a lot, plus I totally got a chubby looking at the LSJ head. Fill that thing up with some bigass cams and go to town on the port work. I'm having flashbacks of the Honda K20 head seeing much potential is in that thing, 300+ n/a hp possibilities anyone?

Daddy is very pleased right now, and wanting to trade off his 99 ASAP!

edit: I hope this is a stupid question, but that's not your patriot L61 head is it? Heh, looks quite stock, but I've got to ask.



Edited 1 time(s). Last edited Wednesday, October 17, 2007 3:02 AM






Re: LSJ vs L61 head PICTURES
Wednesday, October 17, 2007 6:19 AM
no the patriot head is still sitting in work (dirty as hell I might add)

the L61 head featured in this thread is the factory head I removed from the engine I had in my car a year ago (and the original ecotec engine I swapped into the skwirl in '06





Re: LSJ vs L61 head PICTURES
Wednesday, October 17, 2007 7:12 AM
Gameoverracing. wrote:Lots of good pics and info here.... bravo.

Yes, Suncavi already did this swap. I think though (as far as I remember) he is back to the ecotec head again.


Yes he did swap back to the L61 head. he told me he was having tuning issues that they traced back to the head swap. I just do not remember exactly what he said it was from, but he knew why.



FU Tuning



Re: LSJ vs L61 head PICTURES
Thursday, October 18, 2007 7:08 AM
I had no idea the stock L61 heads were so rough. I can only imagine the turbulence the stock head causes. P&P FTW!
Re: LSJ vs L61 head PICTURES
Thursday, October 18, 2007 11:08 AM
David Arestie wrote:I had no idea the stock L61 heads were so rough. I can only imagine the turbulence the stock head causes. P&P FTW!


they look rougher than they actually are

also the J's didnt use the egr in the L61's , so nothing has to be done for it with the LSJ head , and the 05 L61's do not have the egr passage in them







Re: LSJ vs L61 head PICTURES
Thursday, October 18, 2007 11:34 AM
This is a really good thread... As mentioned above, there is a ton of junk on that L61 head that can ported off.


Dan Trump

2004 Cavalier LS Sport - Victory Red
Re: LSJ vs L61 head PICTURES
Tuesday, November 13, 2007 6:19 PM
why make any modifactions for the pcv at all? why not just block the bitch off. its just more emmsions crap. by the way, do the stock cam pulleys mate to the lsj cams?




"boobs now with Riboflabin"
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Re: LSJ vs L61 head PICTURES
Tuesday, November 13, 2007 7:09 PM
PCV valve from wikipedia wrote:As an engine runs, gases from the cylinders leak past the piston's sealing rings into the crankcase (containing the crankshaft and other parts). This leaked gas is sometimes referred to as "blow by" because the pressure within the cylinders "blows" them "by" the piston rings.

These gases include compounds harmful to an engine, particularly hydrocarbons (unburned fuel), as well as carbon dioxide and water vapor. If allowed to remain in the crankcase, or become too concentrated, the harmful compounds will condense out of the air within the crankcase and form corrosive acids and sludge on the engine's interior surfaces.

This can harm the engine as it tends to clog small inner passages, causing overheating, poor lubrication, and high emissions levels. To keep the crankcase air as clean as possible, some sort of ventilation system must be present.


pcv isn't there for emissions only.. its there to keep your engine healthy. blocking it off is not an option if you want your engine to last any long duration of time






Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 7:24 AM
i know this is prolly a stupid question, but whats the point/ benefit to swaping the LSJ head for the L61??? also what does FTW mean??


many changes in the making
my favorite part about doing bodywork,.......... bondo bugers
Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 8:03 AM
cavy tuner911 wrote:i know this is prolly a stupid question, but whats the point/ benefit to swaping the LSJ head for the L61??? also what does FTW mean??


the LSJ is sand cast, which means it has more consistent surface than the L61 head (which is lost-foam cast), and more material for port jobs. it also has stronger water jackets so it'll hold more power.
also, the LSJ has no EGR, so it cleans up under the hood a bit with the extra space from the lack of the EGR triangle (the L61 doesn't have EGR either, but the holes and the casting for it is there.. this is missing altogether on the LSJ head however)

the lack of EGR on the LSJ makes the biggest difference around the exhaust ports however, which really lets them be opened up and aggressively ported.

valve springs between all ecotec heads are supposedly the same, so RPM limits with the factory valvetrain are retained, however the LSJ has sodium filled exhaust valves.. making them a bit better at resisting high heat.


...oh and FTW means for the win





Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 8:52 AM
[quote=97cavie24ls(™)]
David Arestie wrote:I had no idea the stock L61 heads were so rough. I can only imagine the turbulence the stock head causes. P&P FTW!


they look rougher than they actually are

also the J's didnt use the egr in the L61's , so nothing has to be done for it with the LSJ head , and the 05 L61's do not have the egr passage in them

If the 2005 L61 heads dont have the erg passages wouldnt you be able to do a more aggresive port on them? If so use a 05 head and go to town!!






Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 8:57 AM
^^it depends on what they look like around the exhaust ports, but theoretically, yes

also I'm not sure if it was all of 2005MY that had the EGR removed or if they did it as a 2005.5MY kind of thing... if its a 2005.5, those heads will be somewhat difficult to find.

none of this is confirmed yet I'm still trying to find out for sure, but i have seen L61 heads without the EGR triangle.. just haven't see the exhaust ports of said heads








Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 11:46 AM
Skiwirl I got a head without egr but the exhaust ports still have that space underneath ill go to the garage and check it later to make sure. I think i have an 03 head and an 05-06 head Might be from a cobalt i gotta see what the diffrence is between my 03 head.



Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 11:49 AM
what about ignition...the l61 cassette wont fit inn the lsj valve cover



Re: LSJ vs L61 head PICTURES
Wednesday, November 14, 2007 12:58 PM
^^i'm pretty sure the bolt holes line up but the plastic peice physically will not fit, no.

i'll see if i can get some pictures of the two cam covers next to one another for a comparison.






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