Jump to content
  • When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Help! Compression Ratio of S14 Shortblock with E30 M10 Head?


Digby

Recommended Posts

I have what amounts to and S14 shortblock and have intentions of installing it with an E30 M10 head.

Has anyone tried something similar? If so, do you have any idea of what the compression ratio turned out to be?

Thanks.

Digby

1984 318i-Drivable

1984 318i-Parts car with off-road title

Link to comment
Share on other sites

Hi Digby. I've done something similar, although not exactly what you are looking at I don't think. The primary difference is that it sounds like you want to use the stock S14 pistons. The challenge with this is that they are designed for a 4-valve-per cylinder head, not a 2-valve like the E12 heads. As such, you'll likely run into clearance issues and the shape is just not optimized. That said, I know it has been done using a thicker head gasket, but obviously this would reduce your compression ratio. The person who I know that did this was running the motor with a turbo, so low compression makes more sense for this application.

Personally, I ended up getting custom pistons from Ireland which had the S14 bore but were designed for the E12 head. I also used the S14 head-gasket since obviously the M10 head gasket is designed for a much smaller bore and also doesn't have some of the same coolant holes as the S14 one.

Let me know if I can help you with any info, I learned a few little tidbits along the way to do with pairing the E12 head to the S14 block. Also, if you search the archives under "stroker" you'll likely find some good info. Good luck.

Link to comment
Share on other sites

Hi Digby. I've done something similar, although not exactly what you are looking at I don't think. The primary difference is that it sounds like you want to use the stock S14 pistons. The challenge with this is that they are designed for a 4-valve-per cylinder head, not a 2-valve like the E12 heads. As such, you'll likely run into clearance issues and the shape is just not optimized. That said, I know it has been done using a thicker head gasket, but obviously this would reduce your compression ratio. The person who I know that did this was running the motor with a turbo, so low compression makes more sense for this application.

Personally, I ended up getting custom pistons from Ireland which had the S14 bore but were designed for the E12 head. I also used the S14 head-gasket since obviously the M10 head gasket is designed for a much smaller bore and also doesn't have some of the same coolant holes as the S14 one.

Let me know if I can help you with any info, I learned a few little tidbits along the way to do with pairing the E12 head to the S14 block. Also, if you search the archives under "stroker" you'll likely find some good info. Good luck.

Grover,

I much appreciate your insight. And going to custom pistons designed for the E30 head is undoubtedly the better way to go.

As I get further into my project I'm sure I will be getting back to you with questions about installing an M10 head on an S14 block.

Digby Willard

1984 318i-Drivable

1984 318i-Parts car with off-road title

Link to comment
Share on other sites

  • 4 weeks later...

Grover,

Couple-three questions about your S14/E12 engine setup.

1. What compression ratio did you specify for the custom pistons you bought from Ireland Engineering?

2. What octane gasoline do you use in the engine?

3. Did you use stock M10 rods, S14 rods, or custom rods from Ireland Engineering or similar?

Thanks.

Digby

1984 318i-Drivable

1984 318i-Parts car with off-road title

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • BMW Neue Klasse - a birth of a Sports Sedan

    BMW Neue Klasse - a birth of a Sports Sedan

    Unveiling of the Neue Klasse Unveiled in 1961, BMW 1500 sedan was a revolutionary concept at the outset of the '60s. No tail fins or chrome fountains. Instead, what you got was understated and elegant, in a modern sense, exciting to drive as nearly any sports car, and yet still comfortable for four.   The elegant little sedan was an instant sensation. In the 1500, BMW not only found the long-term solution to its dire business straits but, more importantly, created an entirely new
    History of the BMW 2002 and the 02 Series

    History of the BMW 2002 and the 02 Series

    In 1966, BMW was practically unknown in the US unless you were a touring motorcycle enthusiast or had seen an Isetta given away on a quiz show.  BMW’s sales in the US that year were just 1253 cars.  Then BMW 1600-2 came to America’s shores, tripling US sales to 4564 the following year, boosted by favorable articles in the Buff Books. Car and Driver called it “the best $2500 sedan anywhere.”  Road & Track’s road test was equally enthusiastic.  Then, BMW took a cue from American manufacturers,
    The BMW 2002 Production Run

    The BMW 2002 Production Run

    BMW 02 series are like the original Volkswagen Beetles in one way (besides both being German classic cars)—throughout their long production, they all essentially look alike—at least to the uninitiated:  small, boxy, rear-wheel drive, two-door sedan.  Aficionados know better.   Not only were there three other body styles—none, unfortunately, exported to the US—but there were some significant visual and mechanical changes over their eleven-year production run.   I’ve extracted t
  • Upcoming Events

  • Supporting Vendors

×
×
  • Create New...