Parts Car

[Guest PontiacDude210]

I was just given a 1988 Olds Delta 88. It is a 3800 with low miles and a great runner. My 1990 Reatta has not been so well maintained, and has 230k miles on the drivetrain. Is this swap possible?

[Guest PontiacDude210]

I want to pull the olds motor and paint the block, change any older gaskets, and generally tune up the motor. I am not sure on compatibility 88 to 90 though.

[Barney Eaton]

The 3800 V6 engine was mostly unchanged from 1988 to 1990. A recent post shows the intake of the 1988 with 3800 molded into the top, the next year the engine ID was put on the plastic cover. Take plenty of pictures as some wires and connections could vary some. I would switch both the engine and transmission together as your transmission also has 230,000 on it, unless you know it has been rebuilt.

Your Reatta transmission has a 2.97 final drive ratio, the Olds might be slightly different but that should not be a problem.

[DAVES89]

Whenever I have a question I go to Car-Part.com--Used Auto Parts Market and key in what I have and look for what is compatible. So in your case you would key in 1990 Buick Reatta and then the salvage yards will list what they have for sale that will work. I am sure you find the Olds motor there. Also if you look at the "vin #" of the Olds and see that it is a "C" motor it will work. You can also do the same for the transmission.

But Barney's point is well taken take pictures as some things may be different.

[Guest PontiacDude210]

Thanks for the info. I'll make sure it is a C. The molded number on the intake threw me off a little. Are there any differences in the 88 motor as far as performance or fuel consumption?

[padgett]

There are some differences in mounting brackets and such but "should" swap. Keep in mind that the timing chain mechanism was changed for 89 and the 4T60 trans received design improvements every year. Also the 88 Olds may have a different axle ratio.

[2seater]

Everything mentioned is certainly correct to check. I believe 1988 was a transition year where some older Vin 3 engines were being used up in some models, while similar, it is not an exact match. While it doesn't make a difference to the compatibility, the camshaft is a little "hotter" than the later models, but still quite mild. I know I have searched high and low for another one and there is no availability for a service camshaft to match the 1988. A later model is what you would get and is completely interchangeable except for a shim plate behind the nose.

[padgett]

1988: Intake and exhaust lobe lift .271", Intake and exhaust duration 192-193 deg. @ .050" lift. Lobe separation 112.5 deg., 109 deg intake centerline.

1990: Lobe lift; intake .251", exhaust .255, Duration @ .050", intake 187deg, exhaust 189.5deg; Lobe separation 115.5, intake centerline 113 deg.

Think it has 1.6 rockers - anyone know ? AFAIR 89 is same as 90. I understand tht you can get 1.7, 1.8, & 1.9 rockers but might need to convert to rollers.

Really dredging but think only the "C" had the 3800 on the plenium in 88, not the "3". ANyone know ?

[wws944]

Rockers are the same between '88 and '90. Same as '91 and '92 L27 3800s too. In '93 the L27 got roller rockers.

[2seater]

Padgett, that is pretty much what I came up with doing empirical testing of the cams, but that data sums it up nicely. Kinda defies logic how both engines, which are otherwise identical, can carry the same rating? 1.6 rockers in all cases as mentioned above. In any case, the vin 3 engines are not called the 3800.

[padgett]

Had to be mild to be able to pull from 1200 rpm in top/locked. Think Crane reground a stock cam to "a bit more" for Greg.