Pulled the plenum, now what?

[scholtmj]

Pulled the plenum for the first time with the intent to replace the coils, spark plug wires, spark plugs, starter, serp. belt and fuel injectors (FIC). My car has an idle around 1k rpm and it spits black soot out the pipes (and on to the back bumper) even when driving around with modest foot control.

Some observations:
1. Strong smell of gas
2. Air box to IH hoses are VERY hard
3. Plenum runners and IH's are NOT ported
4. All vacuum lines have hose clamps or zip ties installed (Vette Doctors most likely)
5. Secondaries move but I'm not sure I'd call it 'freely'
6. Pretty dirty for only 17k miles!

Some questions:
1. How much HP will I pick up by porting the top end on a 368 motor?
2. What's the part # for IH fuel injector gaskets?
3. Is there anything else I should replace while I'm in there?

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00020-20090720-1652.jpg


http://i486.photobucket.com/albums/rr221/unclescholt/IMG00024-20090720-1653.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00025-20090720-1654.jpg

[ittlfly]

I'm just courious about the strong smell of gas, black soot etc... did you happen to use a scanner to check your O2's readings before you tore it down? I'm just wondering if they are scewed to the lean side or not even working properly. Just a thought.

[tccrab]

Looks like original Multec fuel injectors. Suspect the smell and soot is a injector stuck open.
Were any of the plugs fouled?

Really surprised that a 368 didn't have at least port matching.
:dontknow:

Did the previous owner live on a dirt road?
It's remarkably dirty under there.
My '90 with 11k miles looks almost new by comparison.

TomC
"Crabs"

[scholtmj]

Looks like original Multec fuel injectors. Suspect the smell and soot is a injector stuck open.
Were any of the plugs fouled?

Really surprised that a 368 didn't have at least port matching.
:dontknow:

Did the previous owner live on a dirt road?
It's remarkably dirty under there.
My '90 with 11k miles looks almost new by comparison.

TomC
"Crabs"

I'm glad your motor looks new! Your pictures are going to help me put everything back where it's suppose to go when I'm done!

None of the plugs where fouled but they looked pretty dark. The first owner autocrossed this car for 14k miles in Michigan (best roads in the USA!), the second owner was an older guy who didn't care much for cleaning...I'm just getting started.

I don't think soot would be a byproduct of a lean condition, more due to running rich which points to bad fuel injectors. I don't have a scanner to check the O2 codes but I didn't have a check engine light on either.

[ittlfly]

ie: If there was a vacuum leak, the exhaust gases would be scewed to the lean side. The O2's would report that condition to the ECM which in turn would fatten up the A/F mixture causing a rich condition.

[Jeffvette]

Can you get a better shot of the injector housing and plenum ports?

[scholtmj]

ie: If there was a vacuum leak, the exhaust gases would be scewed to the lean side. The O2's would report that condition to the ECM which in turn would fatten up the A/F mixture causing a rich condition.

Ah, I see what you meant.

Pictures of ports with Jerry's gasket for reference:

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00029-20090721-1346.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00030-20090721-1347.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00031-20090721-1348.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00032-20090721-1348.jpg

[Jeffvette]

Ah, I see what you meant.

Pictures of ports with Jerry's gasket for reference:




The top end has been ported, but as you have found not ported to what todays standards are. You will also find the heads are not up to standards as well.

Who did the 368?

[scholtmj]

The top end has been ported, but as you have found not ported to what todays standards are. You will also find the heads are not up to standards as well.

Who did the 368?

Vette Doctors did it in the 90's but I don't have any information on the specs from them.

[FU]

I'd suggest the plenum and inj. housings get a up to date porting job , while your this far into the project.

[Jeffvette]

Vette Doctors did it in the 90's but I don't have any information on the specs from them.

You mean Kirchoffer did the work.

You are probably missing about 15-20 hp from a current 368. You have headers on the car?

[LGAFF]

I have a set of IHs ported to 36MM if interested, they are ready to go on an exchange basis.....

[scholtmj]

I have a set of IHs ported to 36MM if interested, they are ready to go on an exchange basis.....

Have you done any plenums?

Jeff,
I didn't know Kirchoffer was part of the Vette Doctors... Should I assume the tuning could be improved as well?

I do have headers, Corsa, Samco intake hose and SLP blackwing intake.

[Jeffvette]

Have you done any plenums?

Jeff,
I didn't know Kirchoffer was part of the Vette Doctors... Should I assume the tuning could be improved as well?

I do have headers, Corsa, Samco intake hose and SLP blackwing intake.


He is not really part. Vette Drs farmed the LT5 work to him. Tune and porting could be improved.

[LGAFF]

I have done plenums......my dyno run was recently posted at 391(see LT5 sound), I have also done karterdon's, CCMANOS, and my own. I am working on another plenum for my car right now(the 90).

Plenums do not take as long as the IHs.

[tccrab]

I'm glad your motor looks new! Your pictures are going to help me put everything back where it's suppose to go when I'm done!


Under the plenum:
http://i71.photobucket.com/albums/i159/tccrab/Plenum003.jpg
Close up:
http://i71.photobucket.com/albums/i159/tccrab/Plenum004.jpg
Plenum with Jerry's gasket:
http://i71.photobucket.com/albums/i159/tccrab/Plenum002.jpg
Injector housing with Jerry's gasket:
http://i71.photobucket.com/albums/i159/tccrab/Plenum006.jpg
I'm not seeing very much difference in size between your ports and mine.
But on mine there is clearly a casting ridge inside the injector housing that doesn't appear in yours. It doesn't look like they removed much material, just polished out the rough stuff.
I would bet there's a good 25-50hp waiting to be discovered in your top end.

Your Cam covers look much better than mine. Mine are getting darker and darker.
This winter I'm sending the top end up to JeffVette for a P&P & powder coating, in his bright sliver. Was going to do it this last winter, but replacing the transmission ate up last years upgrade budget. I had the 2nd gear synchro catastrophically fail, it was cheaper to replace than to rebuild. *sigh*
http://i71.photobucket.com/albums/i159/tccrab/Plenum007.jpg
http://i71.photobucket.com/albums/i159/tccrab/Plenum008.jpg

TomC
"Crabs"

[Paul Workman]

There is some hp to be had, based on your pix. These are some "work in progress" shots I took last spring. I patterned them after Pete's and Mark H's work. (I guess it would be considered "modern" with regard to the porting for a 350 ci engine - lots of input from Pete n Marc n Ryan n Locobob n Lee)

Pete's ports are BIG, and Marc H said I really couldn't go too big, especially on the plenum. Tho I used a 36mm ball gauge to guide the burr, after drum sanding and then flapping, the snap gauge showed I was between 36.5 and 37mm throughout:thumbsup:. Or, to put it another way, I had to trim the gaskets with a razor blade...

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/IH3Large.jpg

I extended the porting into the heads by coning the port to the base of the valve guides; almost 3". This shot is a primary(?) port, and the ball is a 36mm.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/IH7Large.jpg

This is a primary port "in progress"...

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/IH8Large.jpg

And this is a secondary port after it too was coned to the valve guide and sanded.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/IH9Large.jpg

From what I understand, most just port match the heads on a top end P&P. But, the transition is very abrupt that way! So, I did the math and came up with a bit over 2.75" "minimum" for a 33 to 36mm transition - which just fit the length of the head's runner up to the valve guide. So...It should be interesting to see what it makes on the dyno.

P.

[scholtmj]

Under the plenum:

Your Cam covers look much better than mine. Mine are getting darker and darker.
This winter I'm sending the top end up to JeffVette for a P&P & powder coating, in his bright sliver.
TomC
"Crabs"

My cam covers are actually polished (just very dirty like the rest of the motor). It makes sense to get the top end re-ported and up to date so I'll do that while it's apart.

[scholtmj]

Made some progress over the weekend. Pulled injectors, IH's, coil packs, alternator, compressor - ready to get to the starter and clean the V. I was surprised at the size of the secondary ports in the head. Compared with Jerry's gasket, they look slightly larger than 37mm.

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00062-20090801-1504.jpg

Injector housing from the bottom:
http://i486.photobucket.com/albums/rr221/unclescholt/IMG00053-20090801-1453.jpg


http://i486.photobucket.com/albums/rr221/unclescholt/IMG00061-20090801-1502.jpg

Old fuel injectors:
http://i486.photobucket.com/albums/rr221/unclescholt/IMG00050-20090801-1452.jpg

"V" looks cleaner than I expected:
http://i486.photobucket.com/albums/rr221/unclescholt/IMG00047-20090801-1417.jpg

Should there be oil here?
http://i486.photobucket.com/albums/rr221/unclescholt/IMG00055-20090801-1454.jpg

[A26B]

Made some progress over the weekend. Pulled injectors, IH's, coil packs, alternator, compressor - ready to get to the starter and clean the V. I was surprised at the size of the secondary ports in the head. Compared with Jerry's gasket, they look slightly larger than 37mm.



For reference, engine drawing show secondary port dia to be 36.54mm dia with a 30deg chamfer, which would make the dia slightly larger at the mating surface. Injector Housing gaskets are made with 36.5mm port size for all ports, primary & secondary.

[flyin ryan]

I'm not crazy about that 'Flat' knocked off the injector boss :cool:. Should be profiled & radiused, not just knock the high spot off call it done. Then the other side, boss isn't even touched :confused:. I could never send something out the door looking like that :neutral:. Definatly due for an update.

[LGAFF]

35MM fooseball Before:

http://i134.photobucket.com/albums/q115/lgaff/DSCN0754.jpg

After:

http://i134.photobucket.com/albums/q115/lgaff/DSCN0755.jpg

[scholtmj]

Looks great! :thumbsup:

I feel an 11 second time slip is in it's future once it's back together.

[LGAFF]

plenum is done, just needs some clean up. bolted them up to a set of ported IHs.


http://i134.photobucket.com/albums/q115/lgaff/DSCN0771.jpg


Still junk on the sides from porting, needs a pressure wash.

[LGAFF]

http://i134.photobucket.com/albums/q115/lgaff/DSCN0758.jpg

[scholtmj]

Old video, before I started taking everything apart. Nothing special but it's all I have so far.

http://i486.photobucket.com/albums/rr221/unclescholt/th_MVI_1961.jpg (http://s486.photobucket.com/albums/rr221/unclescholt/?action=view&current=MVI_1961.flv)

[scholtmj]

A few finished IH pictures.

Anyone interested in getting some porting done, go ask Lee (LGAFF). Great work, great communication, honest and fair guy - even threw in a correct plenum pipe since the one on my plenum was a hack job. Thanks again! :thumbsup:

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2258.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2253.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2256.jpg


Time for some paint!

[LGAFF]

Thanks Matt,

For $700 bucks not bad. I know Matt has a few items for sale out there and my experience is that Matt is a great person to do business with. I was about 90% done with Matt's stuff and I got a call that a forum member needed an IH/Plenum done ASAP. I called Matt and he was nice enough to let me send the plenum/IH I had for him to someone else....Matt was nice enough to help me.....and then even paid me well in advance. I would not hesitate to do business with Matt again. I cannot wait to see the car run at the track with the added HP.

Thanks Matt for giving me a chance. Someone needs to buy the CCWs he has out there.

[mgbrv8]

Now you need to hit it with some of these. I love these things they do a really good job when porting.

http://www.cylinderheadsupply.com/2721.html

Dave

[XfireZ51]

Vette Doctors did it in the 90's but I don't have any information on the specs from them.

Have Lgaff do the porting. Pretty reasonable. With a 368 you definitely need more air.

[LGAFF]

Dominic, I did the porting on this one....36+ all the way through......should breath pretty darn good. These were barely ported by vette doctors or whomever did the work. I am going to start doing another set soon.

[XfireZ51]

Dominic, I did the porting on this one....36+ all the way through......should breath pretty darn good. These were barely ported by vette doctors or whomever did the work. I am going to start doing another set soon.

Just giving you another thumbs up! :dancing

[scholtmj]

Nice weather this weekend so I made some more progress:
New starter installed - used one for sale if someone wants it
New secondary port actuators installed
Re-polished the cam covers and installed stainless hardware
New Accel coils installed
Re-torqued breather box bolts - VD's used large amounts of RTV here
Painted top end with black wrinkle paint....have my doubts about durability
Installed IHs and started the vac hose maze!


Found out my HVAC box had 2 of the required 5 bolts installed :icon_scra


Couple Questions:
1) My replacement secondary actuator valve has a third tube on the 'back' whereas the stock unit only has the 2 facing the back of the block. Is this a 93-95 valve?

2) Cam cover bolts - passenger side went smooth sailing, drivers side not so much. VD's murdered 4 bolts when they reinstalled; I can't even get a T45 to grab. How does one go about removing these?

3) The third connector by the IH coolant temp sensor is for the AC? It's been too long since I took it apart!

[QB93Z]

Couple Questions:
1) My replacement secondary actuator valve has a third tube on the 'back' whereas the stock unit only has the 2 facing the back of the block. Is this a 93-95 valve?

2) Cam cover bolts - passenger side went smooth sailing, drivers side not so much. VD's murdered 4 bolts when they reinstalled; I can't even get a T45 to grab. How does one go about removing these?

3) The third connector by the IH coolant temp sensor is for the AC? It's been too long since I took it apart!


3) Can you post a picture of the connector you are talking about?

1) Here is a picture of the Secondary System Actuator on my 1994 LT5. The third tube has a foam filter to keep debris from being sucked into the system when the Actuator turns off. I believe that the 1990 actuator is fucntionally the same and the later model should work fine for you.

http://i407.photobucket.com/albums/pp152/QB93Z/Misc/DSC01737.jpg

Jim

[scholtmj]

That pictures helps a lot. I wonder when the design changed because I don't have the foam filter. I'll have to make one up.

Third connector is for AC that I put on tonight :thumbsup:

[DDSLT5]

Vette Doctors did it in the 90's but I don't have any information on the specs from them.

Bill Kirchhofer did the work.

[scholtmj]

Progress:
http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2259.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2263.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2268.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2271.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG_2272.jpg

Interesting mix of leaves, stones, cig butts and sticks in the radiator. Plenum will need to come off one more time, but I wanted to see how it looked. NAPA has sent me the wrong power steering line 3 times. Right box/number, wrong part. Once the PS stuff gets back on, throw on the samco hoses and put the radiator back in and I'm done...for a while.

[Hammer]

That pictures helps a lot. I wonder when the design changed because I don't have the foam filter. I'll have to make one up.

Third connector is for AC that I put on tonight :thumbsup:

Believe it or not, you can still get them from GM.
93-95 ZR-1
GM #10159525
AC Delco #219-16

[scholtmj]

This looks interesting.....

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00198-20100304-2039.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00199-20100304-2040.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00197-20100304-2039.jpg

http://i486.photobucket.com/albums/rr221/unclescholt/IMG00205-20100304-2046.jpg

[Jeffvette]

Jeal camshafts eh?

End results....


http://www.pnwzr1.com/images/Jeal/Cams001.jpg

http://www.pnwzr1.com/images/Jeal/Cams002.jpg

http://www.pnwzr1.com/images/Jeal/Follower01.jpg

[scholtmj]

Jeal camshafts eh?

End results....


Since Kirchhofer did the work I assume so.

Do all Jeal cams have similar wear characterstics?

[Jeffvette]

Some more than others. Just find a new set of intake cams, check your lifters for scalloping. And be thankful you caught it in time.

[Z51JEFF]

Jeal camshafts eh?

End results....


http://www.pnwzr1.com/images/Jeal/Cams001.jpg

http://www.pnwzr1.com/images/Jeal/Cams002.jpg

http://www.pnwzr1.com/images/Jeal/Follower01.jpg
I dont know too much about cams................but that looks baaaaaaaaaad.

[XfireZ51]

:jawdrop:

[Pete]

You can regrind a set of stock intakes to the same specs as the Jeals if you like them.
We know stock regrinds work.

Pete

[XfireZ51]

I have a set of stock cams, if needed. :hello:

[scholtmj]

I feel this is going to turn into "while I'm there".....

Stock re-grinds would be considered stage 1? The Jeal lobe must be outdated by now.

[tpepmeie]

Do all Jeal cams have similar wear characterstics?

The Jeal billets I had tested were soft as butter just beneath the surface. In the 30 rockwell range. The heat treatment just wasn't done correctly it appears, and the top hard layer is very very thin. Stock lifters are 62 or so.

Its a shame, really. I *thought* they used Piper Cams at one time, whom I would expect better from. Cant say for sure if these (or the EA22's) are from Piper.