Long time lurker first time poster. First this is by far the best forum Ive lurked on. Tons of knowledge and lots of helpful people. This is my first rebuild of any kind. I'm currently reassembling my 2.8. All machine work and parts are bought so to late for a swap. First question, There are 4 studs (and 6 bolts) that hold the lower intake manifold down. When I removed the intake the studs came out with the nut so I didn't notice there was a difference, 2 long (6 point star end) and 2 short (round end) studs. What corner of the intake manifold do they go in? I laid the intake in place and there seems to be a large gap between the top of the block and the bottom of the intake. Is this normal? Gap is about .075in (3mm). Gap is equal at both ends (timing cover end and distributor end). Intake does sit flush between both heads. Service manual says apply 2-3mm wide and 3-3.5mm thick continuous bead on both surfaces. So that would fill the gap, but it just seems to be a large gap to me. Thanks for looking and appreciate and response.
According to the Fiero Store they should all be the same length. If memory serves me correctly then two parts of the manifold are lower than the other two parts. Not sure which ones, maybe just put the shorter ones in the lower sections if that is the case.
As for the gap that is normal, once you torque it down in sequence it goes to about an 1/8" gap with the gaskets in place. You need to put a 1/4" bead of RTV (I used black) along the ridge, run it up the slant about a 1/4" too. Before you do this however make sure you peen the lower intake and block surfaces where you put the RTV. To do this you just tap a small punch in the center of the ridge about 1/8" apart along the whole ridge. This gives the RTV something to sink into so it does not get sucked into the oil gallery or pushed out.
EDIT: here is a picture I made
[This message has been edited by DaytonTD (edited 08-07-2013).]
Yeah. That gap looks huge, but it's perfectly normal.
I forget what I did to determine which studs went where. I think I set the manifold into place, and then just plugged the studs into the holes. Once they're sitting in the holes, it should become apparent which ones go where. They should all have about the same amount sticking out above the manifold. I'm sure that someone else has a more scientific method, or just knows.
Thanks guys for the quick response. I laid the intake in place to see if I could figure the studs out that's when I discovered the gap. First thought was holy crap what did the machine shop do this cant be right. I feel a lot better now. Do I bottom the studs out? Thanks Dayton. I like that idea with the punch, help the RTV stay in place.
[This message has been edited by gtemplet (edited 08-07-2013).]
There are 4 studs (and 6 bolts) that hold the lower intake manifold down. When I removed the intake the studs came out with the nut so I didn't notice there was a difference, 2 long (6 point star end) and 2 short (round end) studs. What corner of the intake manifold do they go in?
Just wanted to confirm what others were saying about the location of the four studs... here are two pics showing they go at the four corners.
I also looked up the studs in the P22 (parts manual) to see if it showed where the two shorter ones might go but there wasn't enough detailed info. As long as your 4 studs bottom out in the block and stick out enough at each corner to get the nuts on with a couple threads still showing, it won't matter which ones go where.
Great recommendation on the peening, I recommend taking a dremel with a rotary stone and carving a groove in both the lower intake manifold and block mating surface. My newly built 2.8 has ~3500 miles on it and it has started to weep oil above the timing cover from the rtv seal. This is very common for these engines, and especially with the heads settling after being run in it creates some slop in the lower intake manifold. I have seen it recommended to retorque the lower intake manifold after the engine has been broken in for a couple thousand miles.
Longer stud goes on the sensor corner at the front of the engine for the ground wire to battery as well as chassis. Longer stud goes on the opposite corner at the rear for coil mounting plate as I recall. Remaining stud goes to the rear but I can't recall for what..second chassis ground maybe? I'm not looking at one other than in my mind (I'm old so . . . ) the last statment might be in error as I have a bracket pictured in my mind as well. . . It is the dogbone bracket so it may go on the front corner remaining.
Bloozberry: Beautiful intake, makes me wish I would have polished mine now. I painted mine aluminum which I thought looked good until I saw yours. Now its only Indiana: Thanks, I guessed right that is how I put them in. After a closer look at Bloozberry's intake all his studs are round on top. I have 2 that are male torx (6 point star)ended and 2 round.