2.3 8v engine peformance questions? - PeachParts Mercedes-Benz Forum

dbenz1 · #1 03-22-2004, 10:42 PM

Im going to do a rebuild, but I want to do alot of performance to the engine while im at it.

How far can I bore a 2.3 8v safely, but still add alot of performance?

How much should or could the cylinder head by milled to?

If I have too much compression after this rebuild....is it going to require to run higher octane gas?

Can I use new stock cylinder gaskets? Or will I need different ones to work with the bigger bores?

Thanks

mbdoc · #2 03-23-2004, 08:08 AM

What year engine?? There are 3 different 190E 2.3 engines. from 1984-86 the engine was 8/1 compression & had adjustable timing but mad only 120hp. The 1987-88 had 9/1 compression & made 130hp.
The 1991-93 2.3 had a completely different piston & cylinder head & still made around 130hp. More of a smog engine!

Overboring the engine 1.0mm is the limit & you might gain 2-3 hp over standard.

Things like exhaust work & headers will generate more hp than boring the engine. ALSO euro cams with adjustable valves will give the most HP increases.

MTI · #3 03-23-2004, 12:59 PM

Doc, just some chronological corrections . . . the '83 and '84 were the low compression (8.0:1) M102's with solid lifters. In 1985 they upped the compression (9.0:1) and used the hydraulic lifters. Compression pretty much remained the same thereafter, but they tinkered with the CIS computer on the M102 about 4 times.

mbdoc · #4 03-23-2004, 05:18 PM

The USA 1984-86 had hydraulic lifters & 8/1 compression, ONLY the euro engines had mechanical lifters. The 1984 was a 102.961 engine & had multiple belts & was 8/1 compression & only 113hp.
The 1985 & 86 was modified to a single belt BUT remained 8/1 compression but was 122 hp. IN 1987 the 102.985 engine was raised to 9/1 compression (130hp) & timing was controlled by the EZL & can't be changed.

Again this info is FOR USA model engines!

dbenz1 · #5 03-23-2004, 06:03 PM

Quote:

What year engine?? There are 3 different 190E 2.3 engines. from 1984-86 the engine was 8/1 compression & had adjustable timing but mad only 120hp. The 1987-88 had 9/1 compression & made 130hp.

Overboring the engine 1.0mm is the limit & you might gain 2-3 hp over standard.

Things like exhaust work & headers will generate more hp than boring the engine. ALSO euro cams with adjustable valves will give the most HP increases.

Thanks
I have an 85.

You say boring the engine 1.0mm is the limit.......is that per cylinder?

These questions need to be answered if anybody can....it would be much appreciated.

1. How much should or could the cylinder head by milled to?

2. If I have too much compression after this rebuild....is it going to require to run higher octane gas?

3. Can I use new stock cylinder gaskets? Or will I need different ones to work with the bigger bores?

Thanks

mbdoc · #6 03-24-2004, 08:09 AM

The original bore size is 95.5MM & each cylinder can be bored out to 96.5MM. You can remove .5MM from the head w/o problems.

MAKE sure to use the 1987-88 model pistons as they will allow for 9/1 compression. ALSO the block needs to be decked about .15-.2mm so that the pistons have max protrusion

The OE headgasket is designed for the 1MM over-bore.

YOU will need preminum fuel!!

dbenz1 · #7 03-24-2004, 06:18 PM

Thanks alot.

Quote:

MAKE sure to use the 1987-88 model pistons as they will allow for 9/1 compression. ALSO the block needs to be decked about .15-.2mm so that the pistons have max protrusion

Do you think I could go with custom pistons like JE? Would that add more performance than 87-88 model pistons? Or do you think im better off sticking with the 87-88 pistons?

300EVIL · #8 03-24-2004, 09:55 PM

You could probobly get away with increasing compression to 11:1 without driveability issues. However, with custom pistons you would have to deal with piston to head clearance which requires some precision measurement and planning. Also, the pistons, rods and crank would need to be balanced. I would highly suggest purchasing this book; http://www.amazon.com/exec/obidos/tg/detail/-/1884089267/ref=pd_bxgy_img_2/104-9788534-9279938?v=glance&s=books This is a very detailed book and has some great information on building up any high performance engine.
Adam