3500 swap questions

[PCGUY112887]

That back bracket I should be able to make an adapter for here at work, the main issue is that motor mount bolt.... anyone know what size it is so I can search for a tap here at work?

Damn thing... I know I can get it to work if I take the engine back out, but it was a big enough pain getting the flywheel tucked into the tranny and the mount on the bottom in... I really don't want to pull it all back out.

[PCGUY112887]

OK I got the mount in.... this is what worries me now...

The first picture is where the oil filter neck is... just a few inches below it is the sub frame... there is no way an oil filter will fit in there.

The other 2 pictures are of where the headers hit the firewall. The flange clears fine, it's the tubes hitting the side of the firewall... it hits real bad actually. The engine will barely rotate up enough to fit the front dog bone mounts in, because the headers are pressing against the fire blanket on the firewall. I mean I can probably get it to all go in there, but shit it seems like those headers hit so bad that it would catch on fire or something...

[CNCguy]

OK I got the mount in.... this is what worries me now...

The first picture is where the oil filter neck is... just a few inches below it is the sub frame... there is no way an oil filter will fit in there.

Simply remove the oil filter adapter from the 3500 then use a 10mm? allen wrench to remove the nipple from your old engine. The nipple should screw right into the 3500 and your filter will mount just like it did before.

The headers.... no experience here but I would remove any of the sound deadening/heat material that is near the header and give the tunnel a smack or two to get some extra clearance. The rear header should rock downwards under acceleration.

[TazMan]

I was just wondering, about the CTS, does he have to put it in the head for it to work accurately? Could he maybe drill and tap a hole in the thermostat housing? Maybe where it has that little bleeder screw or whatever that plug is in the t-stat housing? I'm going to be faced with the same issue and would rather not drill into one of the heads if it could be avoided.

[CNCguy]

I was just wondering, about the CTS, does he have to put it in the head for it to work accurately? Could he maybe drill and tap a hole in the thermostat housing? Maybe where it has that little bleeder screw or whatever that plug is in the t-stat housing? I'm going to be faced with the same issue and would rather not drill into one of the heads if it could be avoided.

I would think that the CTS needs to be before the thermostat so the ECM will get the correct temps before the T-stat opens.

[bszopi]

I agree with Marc on the oil filter. Just remove the adapter and make it so it mounts directly to the block at an angle.

As far as the CTS goes, the one going to the PCM is before the thermostat. The one that is normally in the head is for the gauge. I have a different alternative to drilling the head, although it probably isn't for everybody. I used to have an Autometer mechanical temp gauge, but it died. Anyway, I had it hooked up with a T-fitting where the heater pipe threaded into the manifold. When the gauge died, I just screwed the stock sender into the T-fitting and it has seemed to work just fine.

[PCGUY112887]

Ah... I didn't know that could come off my old block and I could put that in the 3500... that makes me real happy.

The headers I still worry about... I mean I think they would be fine I am just worried about them burning that fire blanket sound insulation shit it is rubbing on. I doubt I could get very far with a hammer since I would have to pull the engine again to get a good swing.

[3400-95-Modified]

Now these are the SS headers for your application right??

I'm surprised they are that tight of a fit. I knew they were gonna hit my firewall so I had to modify them beyond recognition...

Also I thought the 3500 oil filter adapter was totally different than the 3100 one, as in it's not bolted to the block the same way it’s held on by 3 bolts and when removed it’s not the same style mount as the 3100/3400... I could be wrong. I have a 3500 block in my garage, but I haven’t looked at it in a few months now.

[PCGUY112887]

The S&S headers are for Aleros and GrandAm's, however 3 different people that I know of have put them on w-bodies and reported it being tight but working... however they said the flange hit the firewall (well 1 person said that, the other 2 said they fit close but they worked without modification), nothing about the actual pipes hitting on the side. I mean I have the header half way bolted on there and it's tight but I know it will fit, as long as my firewall doesn't burn or anything.

As for the oil filter nipple, I won't be able to tell till I go home.

[3400-95-Modified]

Thats not a tight fit..

When you have to do something like this to a $500 set of headers... Thats a tight fit...










Trust me that took some balls to do... I was so scared when I started chopping up the collector.

[PCGUY112887]

DAMN! That really sucks... but at least it worked for ya. I see you have a stop in there for EGR/O2 (whichever the stopped one up is)... what size is that and what exactly did you buy to put in there? I need to block mine up.

I keep going back and fourth about my setup being OK. I will leave the fire blanket thingy if I can be sure it won't catch on fire or anything, otherwise I'll cut it away where it hits and maybe but a bit of header wrap on the header where it hits the firewall. Like mentioned earlier, when I am going forward the header will just want to go down, which is fine... reverse the header would want to come come up which is bad, however with my solid motor mount I shouldn't get anymore than maybe a clunk when I go in reverse... I hope at least.

Anyone else agree? I have no experience in dealing with headers...

[3400-95-Modified]

That plug is for the O2 sensor... i was gonna move it down to the 45* bend, but when I welded that bung in I f-ed up the threads so the o2 is temporarly in that location that was plugged... Once i cut the new bung off and weld another on the O2 will sniff all the banks, rather than just the front.

I knew mine was gonna take alot of work to fit, so I was expecting it, but my working conditions made the project take 4 days... it would have taken mearly a few hours If I were able to work in the garage, and not outside in one of the pop up garages.

[PCGUY112887]

Ugh more issues...

I looked under my car today and for some reason, a ton of tranny fluid was on the ground..... I had to bend the tranny fluid dipstick a bit to fit the rear headers in, but just by bending it can it make it leak everywhere? I can't see how it's setup since practically everything blocks view from it.

[3400-95-Modified]

I do know all i did was move my dipstick so the seal wasn't right and the fluid was high enough to dump out the back of the trans where the stick goes in... I bet you just moved it out of alignment and thats why it leaked everywhere.

[PCGUY112887]

Humm... well i'll check it out later, the whole engine is rotated back because of the headers so that + a bit of a leak there would probably equal a good flow of fluid onto the ground.

Anyone know if I can wire my Autometer Oil Pressure Guage straight into the stock oil pressure sensor, or maybe even replace the stock sensor with the autometer? Basically I have it right next to the oil filter and it hangs off at an angle... it comes really close to the motor mount but I got it to fit there. I just tried to put on my AC compressor and where the lines attach to the compressor hits the autometer sender hard, there is no way both will go on there... so either I gotta ditch my oil pressure gauge (don't wanna do) or find another way to feed the gauge. There is another little plug I can undo just to the right of the oil filter and screw in the sender there, but then the oil filter won't go on since their damn sender is so big.

If it's not one thing... it's another. A word to anyone considering this... this is NOT an easy weekend project, this takes tons of time and real patients and a high stress tolerance. I pray that it's worth it.