My HSR Swap
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Pro
Joined: Nov 2009
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From: Maple Grove Minnesota
My HSR Swap
My original plan was to put the 400 I purchased in the 89 but found the ceiling in the garage I have been using isn’t tall enough to get the motor out so this will be done in my drive way this spring.
So out of winter boredom I decided to put the HSR on the L98 to see what effect it would have. Everything is almost ready to fire her up other then I’m stumped as to where the PCV valve hooks up?
Where did you HSR guys hook up the PCV hose? Thanks!
So out of winter boredom I decided to put the HSR on the L98 to see what effect it would have. Everything is almost ready to fire her up other then I’m stumped as to where the PCV valve hooks up?
Where did you HSR guys hook up the PCV hose? Thanks!
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Exactly...removed the motor from my car with a typical (non c4) hood still on.
As you said, take the intake off, get the boom very low, short chain and it will come out.
As you said, take the intake off, get the boom very low, short chain and it will come out.
Last edited by cv67; Mar 26, 2011 at 12:01 PM.
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Pro
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From: Maple Grove Minnesota
I guess I should rephrase this, it’s not just the head room it’s only a one car garage thus not enough room on the side either. If the PCV valve just needs a vacuum source? There is a hole that can be used on the back of the plenum.
Race Director
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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If you delete the EGR, I'm thinking you don't need to screw in (and use) the MAT sensor.
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Thread Starter
Pro
Joined: Nov 2009
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From: Maple Grove Minnesota
Not knowing if the MAT sensor was needed I did put it back on the underside of the plenum. Just went out and picked up another threaded barbed fitting for the PVC hose. Should be able to fire her up tomorrow.
And yes being in Minnesota we have to put up with a lot of rust. Thank God winter is almost over! :cheers
And yes being in Minnesota we have to put up with a lot of rust. Thank God winter is almost over! :cheers
Melting Slicks
Joined: Jan 2005
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From: Clifton Park NY
Passenger side valve cover... I put in a breather
PCV goes to middle larger port of TB on passenger side.
Cap the upper port
Other vac sources on the tb are unused
Back of plenum... on mine its SD so I have a vac to my map sensor, one then goes to fuel regulator and the other to my connections of the brake booster. Any other holes just plug
MAT sensor goes in the bottom of the plenum
PCV goes to middle larger port of TB on passenger side.
Cap the upper port
Other vac sources on the tb are unused
Back of plenum... on mine its SD so I have a vac to my map sensor, one then goes to fuel regulator and the other to my connections of the brake booster. Any other holes just plug
MAT sensor goes in the bottom of the plenum
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From: moraga ca
Melting Slicks
Joined: Jan 2005
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From: Clifton Park NY
Just connect that hose from the pass valve cover to the upper port of the TB... Then connect your PCV to the port just below that... then your done.
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Pro
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From: Maple Grove Minnesota
It’s been a while sense I’ve had a chance to work on this. I everything hooked up and got her running. I haven’t driven it yet but it seems to have made a big difference. 
With it running at idle fuel pressure gage reads 35#’s and goes up to 40+ when given throttle.
Only problem is as soon as I shut her down the fuel pressure drops to zero immediately.
There is no sign of a leak at any connection or at the injectors? What would cause this to happen?
With it running at idle fuel pressure gage reads 35#’s and goes up to 40+ when given throttle.
Only problem is as soon as I shut her down the fuel pressure drops to zero immediately.
There is no sign of a leak at any connection or at the injectors? What would cause this to happen?
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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It’s been a while sense I’ve had a chance to work on this. I everything hooked up and got her running. I haven’t driven it yet but it seems to have made a big difference.
With it running at idle fuel pressure gage reads 35#’s and goes up to 40+ when given throttle.
Only problem is as soon as I shut her down the fuel pressure drops to zero immediately.
There is no sign of a leak at any connection or at the injectors? What would cause this to happen?
With it running at idle fuel pressure gage reads 35#’s and goes up to 40+ when given throttle.
Only problem is as soon as I shut her down the fuel pressure drops to zero immediately.
There is no sign of a leak at any connection or at the injectors? What would cause this to happen?
Most systems have a check valve to hold fuel line/rail pressure. If bad, that would cause it. I think the check valve for fuel pressure is on the fuel pump (in the gas tank).
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From: Maple Grove Minnesota
Thanks Greg, I checked with the local dealership and was told there isn’t a check valve? That it must have something to do with the HSR components causing the leak down.
When I turn the key to on I can hear what sounds like air/gas (but see no fuel) coming from the front passenger side of the HSR where I put a pressure gage. I think I’ll put the Schrader valve in it’s place and see what happens?
When I turn the key to on I can hear what sounds like air/gas (but see no fuel) coming from the front passenger side of the HSR where I put a pressure gage. I think I’ll put the Schrader valve in it’s place and see what happens?
Le Mans Master
Joined: Dec 2002
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From: Seattle Area WA
What you are hearing is most likely the sound of fuel filling/pressurizing an "empty" rail. If indeed as Gregg suggested, and is most likely correct about, the culprit being a faulty check valve you can verify this with some vise grips.
Take off the rubber around the fill cap and you can clamp the return and feed hoses to the gas tank. Turn the key to the ON position and clamp.
If clamping the feed makes the fuel pressure stay up after the 10sec fuel pump cycle then it is most likely a bad check valve (and not really an imminent issue).
If clamping the return causes pressure to stay then it most likely is a bad fuel pressure regulator diaphragm.
If clamping both and the pressure still drops you either aren't doing the clamps tight enough or you have a fuel leak and you should not run the engine until it is fixed!
Take off the rubber around the fill cap and you can clamp the return and feed hoses to the gas tank. Turn the key to the ON position and clamp.
If clamping the feed makes the fuel pressure stay up after the 10sec fuel pump cycle then it is most likely a bad check valve (and not really an imminent issue).
If clamping the return causes pressure to stay then it most likely is a bad fuel pressure regulator diaphragm.
If clamping both and the pressure still drops you either aren't doing the clamps tight enough or you have a fuel leak and you should not run the engine until it is fixed!
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I'd try USA's method for verification.
Also, IIRC, mine takes a second/two to pressurize before startup. But, there's also an 8-rotation delay built into the ECM startup table. Partly, this may be "allowance" for the rail to charge. I also think it may provide time for the oil pump to start circulating.
(Sign note: During tuning, I reduced my pulses from 8 to 4. Seemed more in line with start-up time for other vehicles that way.)
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From: Maple Grove Minnesota
Back to the 400
After all the work getting the HSR on and plumbed I finally got the duel exhaust on. Started it up and WOW! What a difference. 
I think these two mods would have satisfied my need for more power except for one thing.
I couldn’t find the source of an antifreeze leak I would see under the car after running the engine until now. The block has a 3” crack in it.
Not sure how this could have happen as there was plenty of antifreeze in it. 
I was hopping to start driving her on Monday to get away from my SIX mile to the gallon Suburban 2500 with a 7.4 in it but I guess it will have to wait a week or two longer.
Oh well I guess there was a reason after all for purchasing the 400 last fall.
Is Comp Cam Pro Series 230/230 @ .505 480 lift too much cam for a daily driver? This is what is in the motor now. I have a ZZ4 cam I could put in it?
I think these two mods would have satisfied my need for more power except for one thing.
I couldn’t find the source of an antifreeze leak I would see under the car after running the engine until now. The block has a 3” crack in it.
Not sure how this could have happen as there was plenty of antifreeze in it. I was hopping to start driving her on Monday to get away from my SIX mile to the gallon Suburban 2500 with a 7.4 in it but I guess it will have to wait a week or two longer.
Oh well I guess there was a reason after all for purchasing the 400 last fall.
Is Comp Cam Pro Series 230/230 @ .505 480 lift too much cam for a daily driver? This is what is in the motor now. I have a ZZ4 cam I could put in it?
