4.2 m117 heads - PeachParts Mercedes-Benz Forum

rwd4evr · #1 05-22-2019, 03:09 AM

Does anyone have a 4.2 head out of a car or thier intake/exhaust manifold off? I'm trying to find out if they have the bigger ports of the 5.6 heads and what the combustion chamber volume is, without driving hours to a pick a part and wasting awhole day to go "****, that's not gonna help me make power. "

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Roncallo · #2 05-22-2019, 06:42 AM

I cant help you out but as far as I know the 420 M116 was not imported into the states. Finding one at pick a part might be a challenge. A die grinder is your friend.

fonzi · #3 05-22-2019, 11:50 AM

Quote:

Originally Posted by Roncallo

I cant help you out but as far as I know the 420 M116 was not imported into the states. Finding one at pick a part might be a challenge. A die grinder is your friend.

420sel w126 ?

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Frank Reiner · #4 05-22-2019, 12:06 PM

Quote:

Originally Posted by rwd4evr

Does anyone have a 4.2 head out of a car or their intake/exhaust manifold off? I'm trying to find out if they have the bigger ports of the 5.6 heads and what the combustion chamber volume is.

The questions are somewhat irrelevant; five of the bolt locations of the aluminum block heads do not match the corresponding locations of the iron block heads.
But no, the port sizes are smaller than those of the 5.6 heads.

rwd4evr · #5 05-22-2019, 07:22 PM

Quote:

Originally Posted by Roncallo

I cant help you out but as far as I know the 420 M116 was not imported into the states. Finding one at pick a part might be a challenge. A die grinder is your friend.

420sel dirt cheap all over.

rwd4evr · #6 05-22-2019, 07:40 PM

Quote:

Originally Posted by Frank Reiner

The questions are somewhat irrelevant; five of the bolt locations of the aluminum block heads do not match the corresponding locations of the iron block heads.
But no, the port sizes are smaller than those of the 5.6 heads.

From what I understand realigning the bolt holes in the head is a simple machining job. The pre 86 5.0 and all 4.2 have a bigger exhaust valve(and same as a 5.6) than the iron block engines. The 5.6 exhaust ports is way bigger than a 3.5/4.5.. intake valves are larger in the 5.6 and 86^ 5.0. the combustion chamber from the 4.2 would suit my 4.5 better with the same bore, plus the chamber looks smaller in the pics I see on eBay, so less compression loss than a 5.6 head. Unfortunately none of the 4.2 heads are private sales and stores with thousands of items aren't going to go put a digital caliper in the ports for me. I'd love to run an alloy block 5.6 or 5.0 but I just doubt it will take the abuse I give my car, plus it doesn't bolt up to the manual trans. 3.5 heads are one option to just raise compression for power. But the set I have need a full going through. I'd love to know the.4.2 chamber volume since I want to port and redo whatever set Im going to use. Kinda stupid to start with a smaller port head and work it if the 4.2 is similar and has bigger valves and ports. And before anyone says anything about low end losses it in a manual trans drift car. It doesn't do anything below 3500 rpm.

duxthe1 · #7 05-22-2019, 07:47 PM

Quote:

Originally Posted by rwd4evr

I'd love to run an alloy block 5.6 or 5.0 but I just doubt it will take the abuse I give my car,

I seriously doubt you could kill one. If the chain and guides are in good shape and there is oil in the sump, they are pretty much bulletproof.

rwd4evr · #8 05-22-2019, 08:18 PM

Quote:

Originally Posted by duxthe1

I seriously doubt you could kill one. If the chain and guides are in good shape and there is oil in the sump, they are pretty much bulletproof.

Excessive heat is my worry. The alloy cylinders walls and piston coating don't like it. I had a fan clutch go south and it got to 250° on a long drift run before I noticed. Normal abuse at 210-220 when all the Nissan's and BMW have broken and I'm one of the last 10 cars hot lapping happens too. A good alum rad would probably help but **** happens and the iron block is actually bullet proof. Plus it doesn't bolt up to my trans or any manual for that matter.

rwd4evr · #9 05-22-2019, 09:23 PM

If your old enough to remember chevy Vegas, they had the identical Reynolds high silicon alloy block material as Mercedes uses. Bad cooling system lead to the demise of the reputation of that engine after overheating murdered the cylinder walls. Supposedly the twin turbo m119 in the sauber c111 race cars had a alloy bore and lived still but there's a good reason any alloy race block is sleeved.

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fonzi · #10 05-23-2019, 12:06 AM

You’ve got plenty of m119 laying around you could blow up. It only seems logical to stuff one of those in one of the many 107 bodies you’ve got laying around. You could find out how much metal must be cut away on any of the 107’s ready to go to the scrapper.

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rwd4evr · #11 05-23-2019, 03:06 AM

Completely off topic. But it's not just cutting metal to make it fit. It's the steering box in the way, so.rack conversion. It's the master cylinder in the way, so race pedal box. My trans doesn't bolt to it. No working ignition for a m119. It's still an alloy block and cylinder walls and surely will run hotter. I would really love to pull about 250 hp out of the iron 4.5 and call it good. Heads and 5.6 cams will do it I think. Buy a ****ty 420sel take the heads to work and modify a few bolt holes. Clean up the ports a bit.. alot less than rebuilding the whole car essentially. Maybe the next car gets m119 power but not this one.

Roncallo · #12 05-24-2019, 07:10 AM

Quote:

Originally Posted by rwd4evr

If your old enough to remember chevy Vegas, they had the identical Reynolds high silicon alloy block material as Mercedes uses. Bad cooling system lead to the demise of the reputation of that engine after overheating murdered the cylinder walls. Supposedly the twin turbo m119 in the sauber c111 race cars had a alloy bore and lived still but there's a good reason any alloy race block is sleeved.

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When Porsche came out with the 928 they were criticized buy the auto magazines for the AL cylinders. The magazines pointed out the demise of the Vega.

Porsche's response:

"Yes but we have an Engineering staff"

rwd4evr · #13 05-24-2019, 04:18 PM

Yeah apparently the Vega was an open deck block and when the cylinders got hot they moved around on the iron head and caused coolant leakage and came out of plane causing scratched cylider walls. Same a390 alloy with 17 % silicon.

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rwd4evr · #14 05-24-2019, 04:30 PM

There's still no way you can say the alloy cylinder is as tough and resilient as an iron block. In a perfect world the alloy block is fine but **** happens in Motorsports. Maybe I'll torture test one eventually maybe. Manual trans incompatibility Is the biggest issue. Lots of work to end up killing a motor.

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Frank Reiner · #15 05-24-2019, 06:14 PM

Quote:

Originally Posted by rwd4evr

There's still no way you can say the alloy cylinder is as tough and resilient as an iron block. In a perfect world the alloy block is fine but **** happens in Motorsports. Maybe I'll torture test one eventually maybe. Manual trans incompatibility Is the biggest issue. Lots of work to end up killing a motor.

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The intermediate plate (IP) from the iron block bolts to the aluminum block. The top two holes of the IP can be slotted 10mm to match the block holes. The same may or may not have to be done for the bottom two, depending on the sump used.