Engines that would "work" in the Reatta

[RetroJohnny]

A burning question I have had for a while, could you plop a LS or some kind of big block in a Reatta? Not saying I want to do it but is it possible? I've seen S/C 3800's in these, and even Northstars, but nothing else? Anyone have any knowledge on this? Just an interesting topic to think about if I ever win the lottery

[Ronnie]

I don't know of any FWD engine swaps using a Chevy engine  but there was a project a while back to put in  a Chevy engine with rear wheel drive in a Reatta. Read about it here.

[2seater]

I suspect the baby LS (4.8?) might fit as was done in the later full size fwd GM cars, but something equated with Chevrolet in a Buick just curdles my blood. JMHO

[Barney Eaton]

Seem like every time there is a full moon,  someone want to put a different (performance) engine in a Reatta.  Generally the question comes from a new member of the Reatta family.

The issue has been covered before and the extreme answer is you can put any engine in a Reatta if you have enough $$$$.

On the V8 side, GM offered a V8 front drive in a very limited number of cars....the 2006-09 Impala SS, '08-'09 Buick Lacrosse Super, '05-'08 Pontiac GP GXP, '06-'07 Monte Carlo SS but I think all of these used the 5.3 V8

It would not be plug n play but one of these would be a place to start....use the HD transmission that came with them etc.

Converting to rear wheel drive ......is a bigger deal

Good luck

 

PS....if you are searching for one of the above GM cars, they are rare and you might be better off restoring it  than using it for part as they all are pretty rare.

In 4 years there were 49,611 Impala SS V8 made

4 years of GXP Pontiacs produced 17,990

2 years of Monte Carlo's = 14,829

And the poor old Buick Lacrosse only made 2416 in 2 years.  

[DAVES89]

The one that would really know is Daniel. I also remember him saying the "easiest" Reatta to use is the 1991. OBD 2 and a more mainstream braking system.

[ChrisWhewell]

Somebody should pick a motor setup, and make a kit available to easify the swap to a better performing engine. From all the reading I've done, the best I can come up with is heads/ manifold, and clear the restriction out of the rear exh. manifold. Total gain maybe 35-40 ft. lbs. Anything more than that, is beyond my abilities. But, I'd shell out $2500 - $3k if there were a kit offered that would enable me to drop in a series II SC 3800, if it were plug n play.

Edited December 14, 2017 by ChrisWhewell (see edit history)

[2seater]

Barney is correct, the 5.3LS, brothers under the skin, but the 4.8-6.0 are dimensionally similar, so...  I guess my only suggestion is, if going to a lot of work, try something really original. A boosted, modern aluminum V6, or even a 4-cyl, would seem like a good fit and lighten up that heavy front end at the same time.

[2seater]

14 minutes ago, ChrisWhewell said:

Somebody should pick a motor setup, and make a kit available to easify the swap to a better performing engine. From all the reading I've done, the best I can come up with is heads/ manifold, and clear the restriction out of the rear exh. manifold. Total gain maybe 35-40 ft. lbs. Anything more than that, is beyond my abilities. But, I'd shell out $2500 - $3k if there were a kit offered that would enable me to drop in a series II SC 3800, if it were plug n play.

The odds of a kit being developed for a 30ish year old car are probably slim. The closest thing there is to a plug and play is the SC3800. The ECM changes are already known and has been done many times. Dave is 100% right that Daniel has done the most modern swap, and hopefully he will chime in. If you could figure out how to lighten the car down to around 3000#, it would be equivalent to adding 25hp

Edited December 14, 2017 by 2seater (see edit history)

[ChrisWhewell]

anybody know off the top of their head, what the largest intake valve size the combustion chambers will accommodate ? I tried looking it up but can't find anything

[DAVES89]

Maybe Ronnie could move my post on my engine rebuild and swap from his forum to here. I think it is a great read and could answer some of the questions about doing a modified stock build. 

 I am happy with the extra power I got. [And I am getting new injectors for Christmas]! 

[Ronnie]

Dave, I don't have the capability to move your engine thread from ROJ to this forum. It is 11  pages long. However, you could copy the first post you made in the ROJ thread to here and we can discuss it again.  It was an interesting thread.

[2seater]

2 hours ago, ChrisWhewell said:

anybody know off the top of their head, what the largest intake valve size the combustion chambers will accommodate ? I tried looking it up but can't find anything

I am pretty sure 1.78", maybe 1.80", is about all that will fit without moving the guides and re-machining the seats. Stock is 1.71". GN valves are the same size and chamber are very similar, as well as overall valve length. I picked up over 30cfm with basic port cleanup, reshaping the guides and some work in the bowls with new stock size valves. Peak is about 192-195 cfm at .450" lift @ 28"wc. Just for reference, the Buick uses a 10* valve angle and are pretty efficient.

[2seater]

I just tried a feeler gauge between the valves and .060" fits loosely, but .080" will not go, so what I mentioned before is pretty accurate. I don't believe the small 3.8" bore would be any issue at these sizes.

[KDirk]

Another possibility (never been done to my knowledge) would be the Cadillac 4.9l V8 used in the Deville from 91-95 and Eldorado/Seville in 92/93 as the base engine. The Northstar (4.6l) was optional as an "upgrade" though I consider it a crap engine due to the well known head gasket issues. The 4.9 is not high performance but is 200Hp and has massive torque up to about 70 MPH (I know, have a 95 Deville  myself). 

 

This also uses the 4T60E like the 91 Reatta and the cradle with powertrain would be a nearly bolt-in swap. CV axles and the like would need some reworking, and the PCM and instrumentation would be an issue as with most other engine swaps. Most of the accessories (power steering, alternator, A.C. compressor etc.) are nearly identical to the Reatta.  I imagine finding the 4.9l is getting a bit tough now as they were last made in 95 and only used in base Devilles that year. 96 was the year everything went Northstar.

 

KDirk

 

 

 

[2seater]

15 hours ago, 2seater said:

I just tried a feeler gauge between the valves and .060" fits loosely, but .080" will not go, so what I mentioned before is pretty accurate. I don't believe the small 3.8" bore would be any issue at these sizes.

I found a pic of one of my heads in process. There is little room between the valves so any greater than normal intake valve upsizing might be accomplished with a smaller exhaust valve. The black outline is the cylinder bore and the chamber actually extends slightly beyond the cylinder by the intake valve. Those file marks are my interpretation of Singh grooves   I just noticed the spark plugs are my interpretation of an improvement: the side electrode is ground back and sort of pointed to expose more spark on simple Autolite copper core plugs.

 

Edited December 15, 2017 by 2seater (see edit history)

[ChrisWhewell]

thanks for the photo of the cc. wow, there isn't much room in there. The second posting in the link below seems to imply that 1.8" intake valves from an SII engine would go in.... It would be nice if I could just grab some GN heads and slap them on the Reatta, but I suspect that won't work. It would be nice if there were some V6 heads that would bolt right on, which would accommodate 1.94's !!! but that is probably asking too much :) 1.5's on the exhaust side would probably be plenty https://www.gmforum.com/performance-brainstorming-tuning-96/swapping-series-ii-heads-onto-ev6-ln3-si-tall-deck-shortblok-215348/page3/

[ChrisWhewell]

oh, and add some beads of weld to the cc's, kick up compression to about 9.5 - 10, and run premium fuel. All I really want is about 230 ft lbs of Tq, that would really make me smile and I think totally do-able, provided I can find some cyl. head that is friendly. I have all the tools to do the valve job, so that's no problem. Can even put in new bronze guides and use 8mm stems, so valve choice isn't limited. Contemplated going to a slightly higher rocker ratio, but they seem scarce and expensive. ugh, need to do more internet "research" :(

[2seater]

4 hours ago, ChrisWhewell said:

thanks for the photo of the cc. wow, there isn't much room in there. The second posting in the link below seems to imply that 1.8" intake valves from an SII engine would go in.... It would be nice if I could just grab some GN heads and slap them on the Reatta, but I suspect that won't work. It would be nice if there were some V6 heads that would bolt right on, which would accommodate 1.94's !!! but that is probably asking too much 1.5's on the exhaust side would probably be plenty https://www.gmforum.com/performance-brainstorming-tuning-96/swapping-series-ii-heads-onto-ev6-ln3-si-tall-deck-shortblok-215348/page3/

I would guess the Series II head might bolt on however the order of the valves is different, which also moves the ports. The Series II also has a shorter deck height, by almost an inch, so the Series II intake manifold won't work either, maybe with some custom spacers? There is no doubt the SII heads are nice as well as the whole engine. What's not to like, lower and narrower. stronger bottom end (cross-bolted caps) and 26# lighter. The chambers are the same basic shape, but the area between the valves opposite the spark plug is filled in level with the deck so they are heart shaped. Swap the whole engine. Daniel has a SII in and running, or Ryan at GM Tuners can help with that.

 

I recently did flow tests on a set of GN heads as well as LN3, and in stock form, the more modern 3800 head wins out, especially the exhaust. Due to an accident with my phone, (crushed) and my laptop (coffee), I don't have a pic of the two heads handy. The GN head has an old style shaft rocker system too. 

[2seater]

4 hours ago, ChrisWhewell said:

oh, and add some beads of weld to the cc's, kick up compression to about 9.5 - 10, and run premium fuel. All I really want is about 230 ft lbs of Tq, that would really make me smile and I think totally do-able, provided I can find some cyl. head that is friendly. I have all the tools to do the valve job, so that's no problem. Can even put in new bronze guides and use 8mm stems, so valve choice isn't limited. Contemplated going to a slightly higher rocker ratio, but they seem scarce and expensive. ugh, need to do more internet "research"

The chambers are only 38cc as the valve angle is quite flat. Deck the block .020", install '95 series I pistons, and with a stock headgasket = 9.54:1. You can also install Ford 3.8 pistons which have a much smaller dish, same pin diameter and offset. Compression ratios 10:1 and up, run E85. 

 

When flow testing I modified some junk valves and undercut stems or different back cuts do have some merit below about .250" lift. Manley has a nice s/s pro-flow valve. Just be careful to not use Chevy thinking on a Buick engine. They are not the same at all.

[handmedownreatta]

yes if daniel would sat down and tell us all he knows we would all have hot rod reattas.....

[2seater]

1 hour ago, handmedownreatta said:

yes if daniel would sat down and tell us all he knows we would all have hot rod reattas.....

For true on that. At least the Series II is only two decades old, not three Most of what I do is for relatively easy improvement with what we have, costs very little except time and I am the empirical type that just likes to try and see where it goes.

 

 

[2seater]

This is a link to the write-up I did over on ROJ about the porting and testing. I thought it had more photos but no joy. While looking at my notes I found I didn't mention that I did test with no valve at all as well. The valve was installed upside down and held so the end of the stem was flush with the valve guide surface in the port. Stock it peaked at 197 cfm and after massaging as described, it flowed 204 cfm. Surprisingly, I got within 10 cfm with the valve installed, so I called that good. I wish I had the equipment ChrisW mentioned as there are probably some improvements to be made just with the valve job itself.

 

http://reattaowner.com/forum/showthread.php?tid=243

[ChrisWhewell]

The equipment isn't that expensive from https://www.newaymfg.com/ You can cut the seats manually, as I did on three sets of V8 heads. A V6 would take a lot less time. Doing them manually lets you get every seat - perfect - , the important part is to make sure the width of the seat is the correct width on the valve, and also at the right location on the valve. I used a jeweler's eyepiece and a bunch of prussian blue and it took me a long time but was worth it. I learned everything I know from David Vizard. 3-angle cuts and I used stock performance valves having backcuts and undercut stems. The best opportunitie for gains in low lift flow are around the circumference of the seat where it blends with the cc, there is usually about a 0.3-0.5 mm "wall" there. I didn't measure flow, but was pleased with the results, it improved the vette alot, and my old truck is a torque monster. I can't imagine anyone could have done a better job on all of them. Vizard used to have hisstuff available on the web 15 years ago, real high tech physics but clearly explained why most ppl who "port" make mistakes, but I'd like to think by now places like Elliotts and others have it down. Cool stuff.

Edited December 17, 2017 by ChrisWhewell (see edit history)

[ChrisWhewell]

in the video below you can see at 2:08 mins, the dude has got a 3-angle cut, but you also see the ridge or "wall" I mentioned. I wouldn't do a valve job this way, rather, I do each cut manually, start with the throat cut, then the top cut, then the 46* seal cut last. Otherwise with these machines I believe way too much material is un-necessarily removed, lowering compression and detrimental to flow, the idea for me was to remove as little material as possble but still be in spec. Yea, I used a dremel to remove the "wall" after I made the 3 cuts on each - easy to slip and ding your nice new seat surface, so must have a very steady hand and lots of patience. Its actually borderline insanity, but the transition from the cc to the seat on my heads is smooth as a baby's cheeks. I think low lift flow is "where its at"

https://www.youtube.com/watch?v=y5nTXDIgWaM
Edit: in my opinion his seats are too deep. And cutting the seats is only the beginning. Next comes bluing up the valve and inserting it into the guide and rotating it back and forth a few degrees as you press it against the seat. Then, remove and look at where the contact is on the face of the valve. If its not in the right location along the face, then its back to grinding. Most shops won't do this, it takes too much time. Typically have to re-do each seat a couple times to get it perfect. The exhaust side is especially important, if the seating surface isn't at least about 040, I thin k there's a good chance of some valve burnage opportunitie, which means a sad day in the future. Remember, all the heat transfer from that hot exh valve only occurs intermittently, that's super important since even one bad exh seal surface means pulling the head. In fact, on my truck that's why I had to pull the heads, some shop didn't do it right and the valve sunk. Replaced it with a vortec heads :) Those are some of the best. The LT1 gen II were tricky because of intake port wall thin ness issues. On these Reatta's I'd be happy with just going to a bigger valve, that does alot in itself. Edit #6 - sorry, this aaca website got an upgrade beginning of this year and I can't post photos using my Mac. I tried my windows 7 box but that won't work either. These computer folk are always upgrading, but things don't seem to get any better, same as gov. Ppl should learn to be happy with what they have, instead of trying to go after things they don't, so said Glen Campbell :)

Edited December 17, 2017 by ChrisWhewell (see edit history)

[2seater]

1 hour ago, ChrisWhewell said:

The equipment isn't that expensive from https://www.newaymfg.com/ You can cut the seats manually, as I did on three sets of V8 heads. A V6 would take a lot less time. Doing them manually lets you get every seat - perfect - , the important part is to make sure the width of the seat is the correct width on the valve, and also at the right location on the valve. I used a jeweler's eyepiece and a bunch of prussian blue and it took me a long time but was worth it. I learned everything I know from David Vizard. 3-angle cuts and I used stock performance valves having backcuts and undercut stems. The best opportunitie for gains in low lift flow are around the circumference of the seat where it blends with the cc, there is usually about a 0.3-0.5 mm "wall" there. I didn't measure flow, but was pleased with the results, it improved the vette alot, and my old truck is a torque monster. I can't imagine anyone could have done a better job on all of them. Vizard used to have hisstuff available on the web 15 years ago, real high tech physics but clearly explained why most ppl who "port" make mistakes, but I'd like to think by now places like Elliotts and others have it down. Cool stuff.

Have you met David? I have not and he still posts a lot of stuff on Speedtalk. I did take a look at the Neway stuff, but that will have to wait for some time before I get to your level.

[2seater]

1 hour ago, ChrisWhewell said:

in the video below you can see at 2:08 mins, the dude has got a 3-angle cut, but you also see the ridge or "wall" I mentioned. I wouldn't do a valve job this way, rather, I do each cut manually, start with the throat cut, then the top cut, then the 46* seal cut last. Otherwise with these machines I believe way too much material is un-necessarily removed, lowering compression and detrimental to flow, the idea for me was to remove as little material as possble but still be in spec. Yea, I used a dremel to remove the "wall" after I made the 3 cuts on each - easy to slip and ding your nice new seat surface, so must have a very steady hand and lots of patience. Its actually borderline insanity, but the transition from the cc to the seat on my heads is smooth as a baby's cheeks. I think low lift flow is "where its at"

https://www.youtube.com/watch?v=y5nTXDIgWaM
Edit: in my opinion his seats are too deep. And cutting the seats is only the beginning. Next comes bluing up the valve and inserting it into the guide and rotating it back and forth a few degrees as you press it against the seat. Then, remove and look at where the contact is on the face of the valve. If its not in the right location along the face, then its back to grinding. Most shops won't do this, it takes too much time. Typically have to re-do each seat a couple times to get it perfect. The exhaust side is especially important, if the seating surface isn't at least about 040, I thin k there's a good chance of some valve burnage opportunitie, which means a sad day in the future. Remember, all the heat transfer from that hot exh valve only occurs intermittently, that's super important since even one bad exh seal surface means pulling the head. In fact, on my truck that's why I had to pull the heads, some shop didn't do it right and the valve sunk. Replaced it with a vortec heads Those are some of the best. The LT1 gen II were tricky because of intake port wall thin ness issues. On these Reatta's I'd be happy with just going to a bigger valve, that does alot in itself. Edit #6 - sorry, this aaca website got an upgrade beginning of this year and I can't post photos using my Mac. I tried my windows 7 box but that won't work either. These computer folk are always upgrading, but things don't seem to get any better, same as gov. Ppl should learn to be happy with what they have, instead of trying to go after things they don't, so said Glen Campbell

Interesting video, but I lack essentially all of that equipment, yikes. I am not sure about cutting all angles in one go. I would prefer each individually to tailor each one. I too blend the ridges above and below the seat although I have seen arguments that sometimes those edges in the intake stream help breakup the fuel droplets. I don't know and have little way to quantify. By the way, Buicks tend to wide seats, especially the boosted ones. Not great for flow, but long lasting. 

[2seater]

Just for giggles, here is a power curve of three different iterations of the 3800; 1988 pre series I, 1991series I and 1996 series II. Below 2500rpm, the old LN3 is the most powerful of all of them. I know that at least in the Reatta, the '91 final drive ratio was changed to 3.33 vs 2.97, probably to better match the increased rpm for the peaks. Actually the difference is less, more like a 3.25 ratio in comparison due to the larger stock tire/wheel combo. Funny thing about the power curves is '88 thru '90 all match, but the camshaft for the '88 is demonstrably more aggressive, so that should be impossible. Hmmm.

 

 

[wws944]

I almost hesitate to mention it, but another possibility might be to go ‘backwards’ to an ‘86-87 FWD 3.8 block.  I suspect it would be compatible with Grand National parts.  Note that the only difference between ‘86 and ‘87 was the addition of roller lifters in the latter.

[2seater]

4 hours ago, wws944 said:

I almost hesitate to mention it, but another possibility might be to go ‘backwards’ to an ‘86-87 FWD 3.8 block.  I suspect it would be compatible with Grand National parts.  Note that the only difference between ‘86 and ‘87 was the addition of roller lifters in the latter.

You are probably right about some of the compatibility. As a matter of fact, they used fwd heads from the '85 or '86? on the '89 Turbo Trans Am for more clearance on the suspension towers. I never gave it any thought but it might open up possibilities. Something I never really explored as I fool around with the first 3800 because it is what I have. I guess I have not found any evidence the older 3.8 was superior and the '87 n/a fwd engine was rated at 150hp, 200tq, so starting with less. The GN intake manifold may or may not be the same as the fwd configuration but could probably be turned around backwards like ours. As far as I can see, all the rest would be custom but may allow the big parts to be used. Interesting idea.