air bleed with plenum coolant bypass

[brentoleary]

I am planning to put on some SAMCO hoses and bypass my plenum coolant as outlined in the April 2007 Heart of the Beast article. I saw a few pictures where it appears others have bypassed the plenum coolant without air bleed hoses as shown in the write up. I like the cleaner look of no top end plumbing, but I am far more concerned about functionality than looks.

Any thoughts on the bleed hoses?

Any advice in general for the job. This is my first attempt at doing anything to the Z, so I am excited and nervous at the same time. I have a 1995 factory service manual from a previous vette, is it worth ordering the 1991 specific manual and the LT5 supplement before I start or is the 1995 manual close enough for this job?

[VetteMed]

Originally Posted by brentoleary

I am planning to put on some SAMCO hoses and bypass my plenum coolant as outlined in the April 2007 Heart of the Beast article. I saw a few pictures where it appears others have bypassed the plenum coolant without air bleed hoses as shown in the write up. I like the cleaner look of no top end plumbing, but I am far more concerned about functionality than looks.

Any thoughts on the bleed hoses?

Any advice in general for the job. This is my first attempt at doing anything to the Z, so I am excited and nervous at the same time. I have a 1995 factory service manual from a previous vette, is it worth ordering the 1991 specific manual and the LT5 supplement before I start or is the 1995 manual close enough for this job?

I'd suggest having the 91 manual. There were changes throughout the years.

[Hammer]

Hi Brent,

Give us some more details on your car, colors and number. How many miles and we may be able to help more.

Also check out the following websites for some good tech articles and
reference material before you start.

http://pnwzr1.net Enter the site and on the left find the tech section
www.zr1specialist.com

Do get a service manual for the year you are working on though.

Oh yeah, we like pictures too.

Welcome

[Scrrem]

I plugged my injector housings and removed all the coolant tubing from the plenum but was concerned about air pockets forming (Mark H had some issues with this). I drilled and tapped fittings on the back side of the injector housing and ran the hosing under the plenum and back to the recovery tank. Here's some pics of the finished product.
Rich

[brentoleary]

Originally Posted by Hammer

Hi Brent,

Give us some more details on your car, colors and number. How many miles and we may be able to help more.

Also check out the following websites for some good tech articles and
reference material before you start.

http://pnwzr1.net Enter the site and on the left find the tech section
www.zr1specialist.com

Do get a service manual for the year you are working on though.

Oh yeah, we like pictures too.

Welcome

My car is black with gray interior and #1164, with ~118K on the clock. Has some port work (Corey Henderson), OBX headers, Borla exhaust and 4:10 gears. It had a small coolant leak from the Tee on the plenum on the passenger side. I removed and epoxied the Tee, but it still leaks, so I figured I'd try the coolant reroute and get rid of the possibility of a leak.

Thanks to everyone for the input, I'll check out all the links and try to post some pics tonight. I am still waiting for my gasket set from Jerry's so I have some more time to read up before I get started, hopefully this weekend!

[brentoleary]

I have the plenum, injectors and the driver's side injectors housings off and had a few quick questions.


1. When I pulled the injectors off the passengers side I noticed every other injector had two o-rings on it and all but one of these also had a blue plastic cap. I presume the other blue plastic cap is in the injector housing, but I haven't fished it out yet. Does this mean I have a bad injector or can I just replace the cap assuming I can find it once I get the other injector out? I believe they are relatively new (<1yr) FIC injectors if that makes a difference.



2. The gaskets I pulled off were cut to match the porting, so I plan to cut my new ones similarly. I also had to scrape off a ton of permatex from the existing gaskets. Is it advisable use permatex when putting the new plenum, IH housing and IH coolant tube gaskets on?



Note: I also noticed that the gasket was incorrectly installed on the passengers side blocking off the hole to the IH coolant pipes.

Other than this everything is going OK - thanks to all the pointers I've received from the experts!

[Scrrem]

I have done several injector replacements and I have never see injectors with 2 O rings on any of the injectors, primary or secondary. Also, those blue caps are put on when the injectors were shipped, I believe they should have been removed before installation. I went with the FIC stainless injectors and they have performed flawlessly.

I did not use any permetex on my gaskets, the gasket should seal fine by itself. If you ever need to put the plenum in the future, it will make plenum removal easier and no need to replace the gasket.

Rich

[-=Jeff=-]

Rich, that is pretty interesting for the coolant.. I assume it is working out fine.. no air pocket issues

[Scrrem]

Originally Posted by -=Jeff=-

Rich, that is pretty interesting for the coolant.. I assume it is working out fine.. no air pocket issues

It worked out great, all the air blead out fine, no air pockets. I was concerned because the installed fittings are not at the highest point in the injector housing, but no air pockets. I kept a close watch after start up checking for any hot spots.
Rich

[Scrrem]

Originally Posted by Dynomite

I assume you mean watching your temperature gauge. The best is to watch HVAC display engine temps in deg C. Using HVAC Display for Engine Coolant Temperature

Opps. Yeah, I mixed that up. You need to check the temp gauge and do a feel test on the coolant tubes and crossover pipe to ensure water is flowing thru them. Marc told me he discovered the air pocket when he saw his temp guage going up but the lower portion of the coolant tubes and the crossover pipe were stone cold, so he shut down the engine.

Rich