After scouring for days aimlessly - Ive decided to try and fire up a good knowledge packed thread on the Infinity Q45 cylinder head - an ODE to Head if you will - cylindrical that is!
My "new" 1994 motor has arrived - complete with a beautiful set of 94 heads - of which I cant [affordably] use in my 1991 Q45a. Hence, Id like to get these 1991 heads off my old motor more up to par with the rest of the motor - and bolt them on and rock!
1st question Im having - does any of the valve train off the 94's work in the 91's?
So ... any experiences in having Q45 cylinder heads re worked, valve jobs etc ?
Who does these heads?
Costs?
Cautions?
Where to get parts like "forecast" had to - the plastic O rings that the dealer only sells with the [valves ???]
Q45 Cylinder Head thread - the definative head resource
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SOCAL91Q45a
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Everything removable on the 94 heads will transfer to the 91 heads. Of course getting the HLA, valve guides, valve seats out will be no easy task.
A perfection 32 valve head parts exchange might take an expert 50-55 hours and run $3,000- 3,500 for labor........double work remove test reinstall. The qustion is has all the miles warped the old heads and will the new cams fit perfectly to tolerance in the bottom supports. Will they have to be microscopically milled and rehardened.....you can use new tops.
The head must be heated to 200F to remove the HLA and valve guide and all the tolerances checked/adjusted at 200F operatingtemperature.
Probably not worth the effort to remove the valve seats, or guides, or HLA........Just buy new ones and install in old heads about $1000 worth at the max as needed.
Any racing head shop [not your average local slam bam change a valve shop] can probably do the work.........to factory standards. will cost you big.
Your old heads maybe fine......all you may need are new HLA, valve seals, valve stem seals [easy change].........cleaning the coolant and oil passages will be the hard part as you cannot hot dip or oven clean aluminum heads...........the temperature must not go above 250F.
Be careful with the SODIUM filled exhaust valves they can explode and burn in air if badly treated.
Call JWT and ask them which shops they would recommend since you are in California.
Be sure and match valves with springs.......the valve spring seats are machined to make sure the installed valves are at a perfect height!
I calculated that with the 94 ebay longblock it would cost me $6,000 [$7400 with new injectors] to create a brand new 90-93 engine.......just wait till you start transferring everything.
See why Japanese take outs with 30-60k are such a deal [at $1300]....slam bam new chain guides, new water pump, front and rear seals, new spark plugs, reseal the valve covers, new hoses and knock sensors...............you end up with maybe $3,300-$4,000 in the newish engine not $6,500-$7,500 in a brand new version.................even with the $1100 you paid for the long block 94............cheaper to just find a new 94-95Q to put the 94 engine into.
A perfection 32 valve head parts exchange might take an expert 50-55 hours and run $3,000- 3,500 for labor........double work remove test reinstall. The qustion is has all the miles warped the old heads and will the new cams fit perfectly to tolerance in the bottom supports. Will they have to be microscopically milled and rehardened.....you can use new tops.
The head must be heated to 200F to remove the HLA and valve guide and all the tolerances checked/adjusted at 200F operatingtemperature.
Probably not worth the effort to remove the valve seats, or guides, or HLA........Just buy new ones and install in old heads about $1000 worth at the max as needed.
Any racing head shop [not your average local slam bam change a valve shop] can probably do the work.........to factory standards. will cost you big.
Your old heads maybe fine......all you may need are new HLA, valve seals, valve stem seals [easy change].........cleaning the coolant and oil passages will be the hard part as you cannot hot dip or oven clean aluminum heads...........the temperature must not go above 250F.
Be careful with the SODIUM filled exhaust valves they can explode and burn in air if badly treated.
Call JWT and ask them which shops they would recommend since you are in California.
Be sure and match valves with springs.......the valve spring seats are machined to make sure the installed valves are at a perfect height!
I calculated that with the 94 ebay longblock it would cost me $6,000 [$7400 with new injectors] to create a brand new 90-93 engine.......just wait till you start transferring everything.
See why Japanese take outs with 30-60k are such a deal [at $1300]....slam bam new chain guides, new water pump, front and rear seals, new spark plugs, reseal the valve covers, new hoses and knock sensors...............you end up with maybe $3,300-$4,000 in the newish engine not $6,500-$7,500 in a brand new version.................even with the $1100 you paid for the long block 94............cheaper to just find a new 94-95Q to put the 94 engine into.
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SOCAL91Q45a
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- Joined: Sat Aug 16, 2003 2:28 pm
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Thanks Q45Tech .....
"Probably not worth the effort to remove the valve seats, or guides, or HLA........Just buy new ones and install in old heads about $1000 worth at the max as needed."
Agreed ......
"Any racing head shop [not your average local slam bam change a valve shop] can probably do the work........."
We have some connections with the head shop that does all our modular Ford/Lincoln Navi heads - before I counted on them, I wanted to make sure there wasnt anything too exotic about the Q45 heads - so as to not ruin, sure these peeps are way competent, but Q stuff seems to have very intriguing idiosyncracies and are not as common.
""to factory standards. will cost you big.""
This may be an un-realistic [from an expense standpoint"] goal. Perhaps just "freshened" is realistic.
"Your old heads maybe fine......all you may need are new HLA, valve seals, valve stem seals [easy change]........."
Well ... this is what Im "really" counting on.
""Be sure and match valves with springs.......the valve spring seats are machined to make sure the installed valves are at a perfect height!""
Will do!
""I calculated that with the 94 ebay longblock it would cost me $6,000 [$7400 with new injectors] to create a brand new 90-93 engine.......just wait till you start transferring everything.""
I understood that to be ALL new parts - with me re using nothing from the old motor like O2 sensors, plenum, and other accessories. Guess I mis understood. To our knowledge the only non functional aspect of the existing 91 motor is all bottom end. Do I expect to use EVERY item off the 91 motor on the 94 - nope. But I guess me and my wallet are going to learn an expensive lesson.
"Probably not worth the effort to remove the valve seats, or guides, or HLA........Just buy new ones and install in old heads about $1000 worth at the max as needed."
Agreed ......
"Any racing head shop [not your average local slam bam change a valve shop] can probably do the work........."
We have some connections with the head shop that does all our modular Ford/Lincoln Navi heads - before I counted on them, I wanted to make sure there wasnt anything too exotic about the Q45 heads - so as to not ruin, sure these peeps are way competent, but Q stuff seems to have very intriguing idiosyncracies and are not as common.
""to factory standards. will cost you big.""
This may be an un-realistic [from an expense standpoint"] goal. Perhaps just "freshened" is realistic.
"Your old heads maybe fine......all you may need are new HLA, valve seals, valve stem seals [easy change]........."
Well ... this is what Im "really" counting on.
""Be sure and match valves with springs.......the valve spring seats are machined to make sure the installed valves are at a perfect height!""
Will do!
""I calculated that with the 94 ebay longblock it would cost me $6,000 [$7400 with new injectors] to create a brand new 90-93 engine.......just wait till you start transferring everything.""
I understood that to be ALL new parts - with me re using nothing from the old motor like O2 sensors, plenum, and other accessories. Guess I mis understood. To our knowledge the only non functional aspect of the existing 91 motor is all bottom end. Do I expect to use EVERY item off the 91 motor on the 94 - nope. But I guess me and my wallet are going to learn an expensive lesson.
-
SOCAL91Q45a
- Posts: 403
- Joined: Sat Aug 16, 2003 2:28 pm
- Contact:
-
SOCAL91Q45a
- Posts: 403
- Joined: Sat Aug 16, 2003 2:28 pm
- Contact: