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42K views 151 replies 13 participants last post by  ehall 
#1 · (Edited)
I have looked around and it seems that 1995 was the last DeVille with a 4.9 engine. Jasper wants $4k for their kit. remanufactured.com wants less than $2k. I suppose I can get a junkyard mystery motor to test with and see how hard it is to hook up my 4.1 intake. If it works then I'll look around for a hotrod reman.

I am going to autozone on Monday to buy intake manifold gaskets for my 85 4.1 and the 95 4.9 and see if the ports are way different.

Any other hints before I do that? Should I ask for parts from a different year or model than the '95 4.9 engine?
 
#30 ·
Yep the alternator housing looks identical in the catalog pics. I would like to upgrade to 140 amp and this would be a good excuse to do it but I have to look at it in detail, things like rear brace might not work, and the connector pin-out is different from what I remember.

I would like to use the newer power steering setup since there is actual aftermarket support for it (you can buy a pulley for it). I'm pretty sure I can bolt it on but I don't know what kind of hard line work will be needed. I don't know if the brace is the same or not either.

The A/C is a bit of a challenge. The only significant difference I can see from the catalog pics is that the 85 compressor has an extra mounting ear for the smog pump to bolt onto, so I should be able to bolt it to the block and just leave that ear unused. If I have to swap compressors I may have to change hoses and such due to differences in the fittings (haven't looked yet but its very common for fittings to change between R-12 and R-134a systems). I still have the original R-12 charge (26 years!) and am trying to figure out if I can keep it during the swap somehow :)

I am hoping to be able to keep my 4.1 valve covers and air filter so that it looks stock
 
#31 ·
As for the bolting up the 4.1 alt on a 4.9 block the rear bolt wont match the block but the rear casing of the alternator needs to be turned so the connector will fit. As for the connnectors for the alternator to the 4.9 block it fits I will post pics when I get home
 
#33 ·
The engine came into the shop and I tore it down to the intake. I took some pictures while I was hacking on it but forgot the last AFTER pic, so I will post those tomorrow. The only real problem I have found was an abnormal leak on the left side of the oil pan gasket. There was also some oil higher up the left side that looked like the valve cover was leaking, but the oil may have been riding up.





We are replacing stuff that would be hard to fix later (within reason) in order to reset maintenance intervals, so we are doing seals and gaskets for the rear main, the timing cover set (including front main), intake manifold , the oil pan and the valve covers, along with water pump and a couple of other things. Anything that's on top of the engine will be swapped as needed, not as prevention.

It's really interesting that almost all of the Fel-Pro boxes say the applications are from 1985 4.1 to 1995 4.9. One difference is that the valve covers are scalloped on top to provide room for the fuel injector ports, which means they are a different shape than the boxy rectangular valve cover. I may have to use a 4.5 TBI intake just so I'm not advertising the "V8 PFI" in big red letters every day (the letters are embossed in the valve cover so they can't be sanded off).

I am starting my pile of leftover parts with the entire injector rail, injectors, entire engine harness, throttle body with air cleaner, and distributor. If you want dibs on something send me a PM otherwise I'll eBay the stuff I don't need when it's over.







My deal with the shop is that they will replace any of the parts that may require significant disassembly to repair later, so they are doing most of the gaskets and seals, and will reinstall the intake after I plug off the port injector holes (assuming I keep it).

I still need to go to the junkyards and figure out the parts interchange. I think I will keep my existing alt and A/C compressor, and am mostly just interested in the power steering. There are a couple of companies selling reservoirs and pulleys so I could probably build a whole system from retail parts, and hard line is still the issue.
 
#34 ·
NAPA has power steering hoses for 91 DeVille... It would be nice if that worked with the 85 rack and pinion

The part numbers are NPS 73273 (supply) and NPS 72844 (return)
 
#36 ·
Here are some more pics, one with everything removed down to the intake, then with the intake also removed





I'm guessing the blue dot on the water pump is significant, but I don't know what it means. The UPC bar code isn't really legible, but I'm guessing it's indicative of a replacement water pump. Maybe the blue dot indicates that it is a rebuilt water pump. Hopefully the engine wasn't overheated. When I was stripping it all down, some green coolant came out of the hose, which indicates that the system had not turned to mud, although you can see a little bit of rust in the outside water ports in the second pic.

The valve springs on the right side have some kind of green paint on them. No idea what that means, the head mechanic here thinks it's just assembly clue marking.

The left side has more varnish than the right side, but (1) every 4.x I've looked at is like that, and (2) the varnish is still very light.

The O2 sensor has a white tip and is clean. Exhaust manifolds are clean inside too. This engine was babied or has low miles, or both maybe. FWIW the reclamation house that sold me the engine said they did not know how to pull mileage from the digital dash in the early 90s, and it wasn't until later that they figured out they could just apply battery voltage... so mileage is unknown but I am guessing around 80k miles, give or take 20k.

The throttle body openings in the manifold are 76-77mm. The holes are not machined perfectly round.

I was unable to properly measure the fuel injector ports since the tips of calipers would not reach that far down. However I tried a few bolts and 14mm was an exact fit. I think I am going to use 9/16 freeze plugs with red loctite to guarantee a snug fit.
 
#37 ·
The varnish is nothing to worry about and will return if you bother to take the time to clean it. It's due to the PCV flow.

Not sure about the blue marking, which looks vivid and clean. Who knows, could even be from the junkyard who pulled the motor. Maybe they have a color system for organization in the warehouse (if this engine was pulled a while ago).
 
#38 ·
I spent some time looking at a complete 4.9 and I think I am going to just keep my accessories. I might change to the newer-style pump and bracket after I do the swap but it doesn't look like there is any significant benefit other than availability, and I already have lots of spare parts for my 85.

The same junkyard advertised a 1989 4.5 intake but the one they pulled down to show me was PFI.

For the injection ports, Dorman has a set of brass cup-style freeze plugs that look to be almost perfect. Part num 565-008 is a box of 10 9/16th (14.36mm) deep-wall plugs. They should be a snug fit in the 14mm hole. My plan is to tap them all the way down to the runners, seal the bottom with red loctite, and then fill the upper cavity with black RTV.



Waiting on parts and for the local shop to install the seals.
 
#39 ·
Well I was looking at my 4.1 accessories and I found a leak in the high-pressure steering line so I gotta do something sooner rather than later. The hoses that NAPA shows for the 85 are clearly incorrect, and they changed often as GM improved the pump assembly. It's looking more and more like the smart thing to do is replace the steering pump and hoses with parts for the 4.9 and get it over with.

According to Cardone the rack and pinion is the same part (so inlets are in the same position), and I assume it's mounted in the same place at the back of the sub-frame. If that's the case then I should be able to just replace the pump/reservoir/bracket assembly ($50 at the junkyard for parts from a 91) and buy new hard lines for that year ($60 at NAPA). Seems reasonable assuming the donor pump works.
 
#40 ·
I learned two things today.

First is that these cars have a power steering fluid cooler that I did not know about. I kept reading about R&P to cooler hose and thinking WTF the diesels have coolers not the gas, but sure enough there is hard line going along the driver side fender and then turning into a little rubber hose that is looped in front of the radiator. Not much of a cooler but I'm sure it works a little bit (and it's a good place to install a real PS cooler later), anyways the lesson is that they actually do have one.

Second is that the return line is supposed to be rubber from the R&P up, but on my car somebody installed a high-pressure line for the return, so I have hard line for both the supply and return lines that go behind the serp belt pulleys. I imagine the belt broke and tore the soft line at some point, which then led one of my mechanics to get clever and install hard line for the return, but either way it has confused me to no end trying to match that damn hard line with something in the catalogs.

I still don't know why the 91 DeVille has such a longer high-pressure line. I'll see if I can raid the shop's alldata discs tomorrow and look at the routing.
 
#41 ·
After looking at the hoses and thinking about my options I decided to pull the whole power steering assembly from a 91 SDV at the junkyard. Basically I removed the tensioner bracket from the engine and kept the pump, reservoir, and pulley as a single unit. I also followed the hard lines down the engine until they met the soft parts, then cut them off so I would have the hard line to work with. For the high-pressure line it looks like I can just buy another 85 line and install it (same fitting at the pump). For the low-pressure return, the 91 setup has a quick disconnect fitting at the reservoir adapter piece so I will splice the engine-side piece of hard-line into the existing cooler return line and call that done. That gets me the new gear without having to install the new style plumbing.

I also grabbed the alternator bracket in case I want to change over later, but I am still planning to reuse the one on my 85.

I also grabbed a small piece of pipe that is used as a bracket for the A/C compressor on the 4.9. The 4.1 and 4.5 had the compressor bolted onto the smog pump, but when the pump was deleted on the 4.9 they used a little piece of pipe as a substitute bracket, and I needed that piece to delete the smog pump.

Parts are still coming in, still waiting for the shop to install the seals and gaskets.
 
#42 ·
Got the brass plugs today and did some quick fitment tests. The holes are 14mm and the plugs are ~14.3mm, so they are too big to push in but they deform and tap in with a 12mm bolt pretty well.



The shop guys think we should use Permatex Right Stuff to seal up the top. I'm tempted to use it for the entire hole. The injectors are kind of cone-shaped so the sealant won't fall through, and we're only talking about 20 mercury inches of vacuum pressure. Fuel injectors are plastic with an O-ring and they don't fall apart or anything. The brass would be nice to ensure that nothing falls through but honestly I think I can make a smoother seal in the runners with just the gasket maker

I'm running the manifold through the dishwasher now to remove as much grease as possible, and will do the real sealing work tomorrow.
 
#43 ·
This all sounds unnecessarily risky to me, like patching a rad hose with duct tape. You are basically creating 8 extra potential vacuum leak points over a regular TBI manifold. If you are really set on using the PFI manifold, instead of patching it up with some plugs and sealant, you might want to think about having the holes heliarced shut for a more durable solution that you won't have to worry about.
 
#44 ·
If it fails it's just a vacuum leak. The real risks are having something hard fall in, and having to pull the manifold to close it again.

I'll make a decision today. There is a series of junkyards around Baltimore that charge $25 for an intake manifold so I can still go up there and pull a 4.5 TBI intake assuming I can find one.
 
#45 ·
The brass inserts deformed in weird ways and the more they were banged on the more they deformed. For instance, one wall of the cup would stretch out way longer than the others and there was no way to shrink it down again. So the plugs became less useful the more they were worked, and after a few minutes of trying to work them they were essentially unusable.

Rather than try to work on the 4.9 anymore I am now trying to find a 4.5 TBI intake. Although I think the Right Stuff would hold up fine as filler (epoxy and welding and other "permanent" modifications are not options), there are some other annoyances about the 4.9 and I think that long term I would be happier with a pure TBI setup. Unfortunately it looks like the only close junkyard with a reasonable price is in Delaware for $75 (junkyards around here want $150 and ebay is in the $80+ range), or I can go further afield like NY or OH and order one for $50ish. Either way nothing happening until Monday, then it will take a few days for the parts to arrive.

While I was at the shop today I replaced the rocker pivots with new pieces, removed the old water pump and polished the aluminum, and degunked the rest of the engine and parts. Everything is ready and waiting, and we can start assembly next week.

I keep forgetting to look at the brake booster vacuum setup on the 4.9 DeVilles... where does the vacuum supply come from? They don't have a supplemental vacuum pump right? Any pics would be great. I'm thinking about simplifying some of the vacuum setup and may delete the vacuum pump or (more likely) put it on a pressure switch. In either case I will need to isolate the brake booster vacuum supply
 
#47 ·
I keep forgetting to look at the brake booster vacuum setup on the 4.9 DeVilles... where does the vacuum supply come from? They don't have a supplemental vacuum pump right? Any pics would be great. I'm thinking about simplifying some of the vacuum setup and may delete the vacuum pump or (more likely) put it on a pressure switch. In either case I will need to isolate the brake booster vacuum supply
Vacuum supply comes straight from the TB, no assist from a pump.
 
#46 ·
I recall a post from Bbob saying that there were minor differences between the 4.1, 4.5, and or 4.9 concerning either the gasket mating areas or the coolant passages. I cannot for the life of me remember what thread that was... I was browsing posts from ages ago deep into the 4.x section. I'll try to find it again...
 
#48 ·
Several years ago I bought 4.1 and 4.9 manifold gasket sets and compared the holes, but I don't remember all the details. What I do remember is thinking that I needed to use the 4.9 gasket set since the ports were larger, and it would ensure that the gasket was pinched between the intake and the head (if I tried to use the smaller gaskets it would suspend over the holes in the block). I haven't looked at a 4.5 gasket but I'm guessing that it's pretty much the same situation.

My hope is that since the 4.9 and 4.5 PFI manifolds are the same part number that the later 4.5 TBI manifold will also be free flowing. There are multiple part numbers so hard to keep track of what is what.
 
#49 ·
On 05-06-08 06:59 PM, edahall wrote

We changed over the 4.1 on my dads 1987 Deville. We used the whole 4.9 motor but used a 4.5 intake manifold and the original 4.1 TBI. The coolant passages on the 4.9 heads don't exactly match the 4.5 intake manifold so it was modified to mate up with some JB weld and some grinding. I don't have any pictures but pictures would not do any good because both engines look identical.
On 03-31-04 11:38 AM, BeelzeBob wrote

I am not sure that your original 4.1 manifold will bolt onto the 4.9. I tend to think it would although I know the coolant ports will not match at the coolant crossover at the front of the engine. The ports in the head (for the coolant) are different shaped than the ports in the manifold....I think that they will still seal up, though....with some liberal use of RTV/silicone. Just glue the manifold in that area with the RTV and let it set up for at least 24 hours before filling with coolant. If you take the intake gasket and line them up to the ports on the head and intake it would be obvious. Use the 4.1 intake gaskets as they would fit the best.
There are several mentions of this general subject but some of them talk about head-to-block alignment and others are just guessing. There are only a few posts like the ones above that are definitive. Looking at the pictures in the 4.x Rebuilder scans, it doesn't seem like the intakes are that different. In any event modifications are doable.
 
#50 ·
I looked at the 4.9 and 4.5 gaskets some, it looks like the water channel on the 4.9 is slight taller and narrower (more square) but still the same basic shape. It doesn't look like it will be very hard to fill in the differences.

I bought an intake and throttle body from an 89 4.5 out of a junkyard in upstate NY (good price on the pair), should have them in the middle of the week
 
#51 ·
After reading about other people's experience with the timing cover and thinking about the corrosion damage on mine I decided to just replace it so I bought one of those too. I hope I won't find damage on the inlet--it's getting damn expensive to buy clean-up parts.
 
#52 ·
Yeah, the inlet is usually the most sensitive component of the assembly. Those fine threads for the 10mm bolts don't hold up well after 20 years, and are generally overtorqued by inattentive and/or novice mechanics replacing the water pump. This is the cause of many 4.X water pump leaks, especially the do-overs. When installed correctly, the 4.X water pump is relatively troublefree.

The timing cover can be cleaned up with tap and a wirewheel as long as none of the studs pull out or loosen on disassembly. If the front crank seal was leaking, the new cover will come with a new seal pressed in.
 
#53 ·
Here's a pic of the front cover. You can see how the aluminum is pitted along the old gasket seam. This is why I bought another one... even if I could get a seal this time it would only be temporary.



The back side of the cover looked fine. The inlet had some minor rust spots on the outside but the inside looked pretty good. I have cleaned and painted it anyway.
 
#54 ·
Somebody put pictures and diagrams of the 4.5 vacuum lines here which is very useful for planning purposes. I might just switch to the 4.5 vacuum lines, minus the AIR pump valving. The only real concern is that the 4.1 did not have a reservoir canister (it had the pump so it did not need a reservoir). I might install an old-school coffee can reservoir in the spot where the AIR pump inlet filter canister currently sits but I think I will also try to integrate the vacuum pump with some kind of switch since it's a more technically advanced setup. Interestingly, some of my google searches for vacuum switches have turned up articles about the brake light vacuum warning switch on the SeVille is supposed to act as a pressure switch for the vacuum pump too but I'm pretty sure my DeVille does not work that way--the booster check valve prevents low vacuum, and I never see the light again after startup, so it would not be useful as a double-duty switch. Maybe the Seville has another secondary switch somewhere.
 
#55 ·
I said earlier that I painted the water inlet but unfortunately I had a lot of problems with adhesion and the paint just wouldn't set up properly. There were also some small rust patches that I wasn't able to clean properly. The dealer wants $80 for the inlet so I took it to a local small-job machine shop and had them sandblast it for $20. It looks and feels like aluminum under the paint, but it's magnetic and it had some rust so it's some kind of steel. The pieces look to be held by copper brazing. Same part number for all of the 4.x engines btw.



Wiped it down with mineral spirits and painted it with engine enamel (the same stuff I painted my brake calipers with a few years ago), and itt should stick pretty good this time



The 4.5 TBI throttle body showed up from the junkyard but the intake manifold hasn't arrived yet. The large pipe sticking out the corner is for the brake booster vacuum.



Here's a pic of the 4.9 PFI throttle body for comparison. Some of the vacuum lines are in the same place but the overall layout is just completely different--even the throttle cable hookup is completely different.



I haven't checked everything for sure but I think the butterfly valves are the same. It will be interesting to compare the stock bore size of the 4.1 vs 4.5 vs 4.9. My bet is they are the same.
 
#56 ·
I haven't checked everything for sure but I think the butterfly valves are the same. It will be interesting to compare the stock bore size of the 4.1 vs 4.5 vs 4.9. My bet is they are the same.
I remembered I had the 4.9 throttle body gasket, so I did some quick measurements. On the 4.9 throttle body there is about 1/16th of an inch lip before the gasket, but on the 4.5 throttle body there is about 1/8th of an inch lip. This is all metric and I was not able to line this stuff up perfectly, so my assumption is that there is a 1-2mm difference in the lip between the bore and the gasket edge, meaning 2-4 mm difference in overall bore diameter. GM clearly thought it would be worthwhile to have a larger throttle body so I will try to get the 4.1 or 4.5 units bored to match the gasket. I don't know the 4.1 size yet so I will do have to do that later.
 
#57 ·
If I remember correctly, those gaskets are completely different animals. I'm not sure about the bores themselves, but the TBI gaskets are a spacer type gasket with inserts in each bolt hole to control crush. The TBI gasket is a good 1/4" thick. The PFI gaskets are just a regular flat gasket. Might want to consider that in your decision.
 
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