Metric Mechanics Rally engine vs Numbers matching rebuild

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Matt McCall

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All,
On my euro '72 CSI project I am wondering which way to go on the engine. Jim is making new pistons and titanium rods that are a lot lighter and it is a very hot engine if I buy his new Rally 3500 3600 engine. However I have the original numbers matching block. Which has a newer '85 casting head on it. Should I have him rebuild the old smaller M30 so I can say numbers matching. Or go with the newer rebuild that will be faster and funner? If I do the latter I can always keep the numbers matching block in case I, or my children after me, want to sell. Please give me your thoughts.
 
If the MM engine gets you to more than 230HP I would go for that and enjoy the driving difference. But then again my ideal scenario would be to fit an M90. My 1977 Euro E24 had an M90 and I still miss them...
 
I talked with Jim and the team for a bit about getting a M30 built up. They sounded pretty knowledgeable, and they have a backlog as long as my coupe expense list. However, they also have had some issues with newer motors that have not been good for them. Also, I have never, ever seen an actual dyno from one of their engines, despite everyone asking about it.
 
Or if you want to explore the M90 option I would:

a) ask somebody with an M90 E9 or E24 to test drive the car.
b) ask SFDon about an M90 build, I did ask him when I was rebuilding the M30 for my 87 E24, but it was not easy for an automatic and you cannot go back in years (like using an M90 older than 1987). You may not have these issues.
 
You know, this whole "#s matching" stuff started when chevrolet's became collectible. Reason is that you couldn't tell if a Camaro, Corvette, Chevelle, etc. had a high performance engine in it since it was not in the VIN.

W/o property documentation (original window sticker, tank sticker on '67-71 vettes, protecto plate) one way of determining the real deal is having the #s matching BORN WITH engine (i.e NOT a re-stamp).

For all other cars, with the engine type/size in the VIN, it's not of huge importance of having the "#s matching" engine.

Maybe if you have a CSL, it would be a nice bonus to have the #s matching block, but even then, you can tell it's a CSL w/the VIN.

I say, keep the block in the shed (grease up the journals, bores) and use the ready-to-run "big block".
 
I'm not so sure the m90/M88 is worth all the hassle and additional cost. If you were building an accurate grp5 csl clone or something but getting the m30 block to make same/similar power isn't difficult. It's just the bragging rights and even then 90% of folks wouldn't know what you are talking about. Get Don or Terry Tinney to build you a m30 hotrod motor and bypass all the hassle and time trying to find a decent m88/90 is probably the fastest /cost effective way to get up and rolling... All my 2.5 cents of course!
 
teahead said:
...For all other cars, with the engine type/size in the VIN, it's not of huge importance of having the "#s matching" engine.
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The 17 character VIN that is still used today started in 1981. Before that, each automaker used different characters to make up their own, unique "VIN" for their own purposes. Some may have had engine type/size in their VIN but I don't know which ones those would be.
 
i would worry about matching numbers if you have a concours car or one that you want to get to concours condition. if you have a CSL, then you want to keep the matching numbers ... that being said, the Bat2 that just sold for 600 large did not have a matching numbers engine.

i want to echo what Arde suggested - talk to SFDon about a new engine for your coupe. there are 3 worthy options that are affordable. the m30 b35, the euro m30 b34 or the euro m90. all are easily adaptable into a coupe. the m88, s38 are different animals, being twin cam engines ... they produce more HP, but are a more expensive build and the integration into a coupe is a lot more complex.

the first 3 are 3.5L engines that can produce 240 hp relatively easily as they started with 208 to 215hp (initially). if you do an engine swap, keep the original matching numbers block as you can always go back if numbers matching ever becomes mission critical for value.

now to speak to what i like about SFDon's swaps - you get an engine that looks like it was original to a coupe ... there are visual differences, but he uses the C tube manifold like what came in the CSi. everything gets the attention to detail to look like a brand new engine ... and besides everything else anybody can add ... you will make a great friend along the way. one last thing, there are a couple of options on fuel injection - you can go the b35 motronics 1.3 route ... or the megasquirt route. you will get more flexibility and ease of maintenance with the megasquirt route (IMHO)
 
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What are the full specs of Jim's " Rally 3500 3600 engine"?

HP, TQ, Compression ratio, cam used, induction, ignition, etc.
 
Have a look here: https://metricmechanic.com/engines/

You're welcome

But note the very recent post which I quote here "For those of you who know Jim Rowe I thought I would give an update. Last week he had open heart surgery and is now recovering at home. Give him a ring or send him a text if you care to and encourage him."
 
Honolulu said:
Have a look here: https://metricmechanic.com/engines/

You're welcome

But note the very recent post which I quote here "For those of you who know Jim Rowe I thought I would give an update. Last week he had open heart surgery and is now recovering at home. Give him a ring or send him a text if you care to and encourage him."
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Does he have an username on this forum? We can start a thread and wish him well.
 
M,

You have a number of directions that you can go as mentioned. Ask yourself what you want the car to be/do and start having conversations with the 'builders'. Then prepare for a 'journey'.

As someone who is anxiously awaiting the completion of a sweet hot rod M30, brace yourself for unforeseen delays and expenses along the way. Turnaround times, labor, and supply chain issues are realities beyond your control.

When I embarked on my new build journey last spring, we had a target completion date in September.....now all I want for Xmas is my favorite toy back. I have heard that that in today's world that's a pretty good 'turn-around' time. This is/will be including install. I have heard that some builders have a 2 year wait list......

Be patient, though it can be hard to sometimes. ;)

Good Luck!
 
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Matt - Not to add more complexity to your decision, but as Rob noted, there are a number of coupe owners who have gone to the stock M30b35 engine. Specifically, the engine from a 87-92 735 or 88-89 635CSi, 87-92 e34, all using Motronic 1.3.

This not as sexy as some of the alternatives you are considering, but it is a straight forward swap, any BMW mechanic can service this engine, and the engine has gobs of low end torque, which makes it enjoyable in the vast majority of driving we do. Moreover, going this route would probably get your car on the road a year earlier than building an engine.
 
x_atlas0 said:
I talked with Jim and the team for a bit about getting a M30 built up. They sounded pretty knowledgeable, and they have a backlog as long as my coupe expense list. However, they also have had some issues with newer motors that have not been good for them. Also, I have never, ever seen an actual dyno from one of their engines, despite everyone asking about it.
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Gary Knox bought a coupe with a MM engine in it (which he sold on BAT last year). If I remember correctly, Gary questioned the hp claims, but nonetheless felt the engine was very smooth and strong.

To be honest, I think most of us would have a hard time differentiating a 215 hp engine from a 230 hp engine, particularly on the street. And if the 215 hp engine made better low end torque, we would probably prefer the lower hp engine.
 
Ohmess said:
To be honest, I think most of us would have a hard time differentiating a 215 hp engine from a 230 hp engine, particularly on the street. And if the 215 hp engine made better low end torque, we would probably prefer the lower hp engine.
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Perhaps, but I can tell I am not driving the M90 based E24 in my sleep... Pictured below. It has the rims Chris hates, but I like them just based on good memories...
 

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teahead said:
You know, this whole "#s matching" stuff started when chevrolet's became collectible. Reason is that you couldn't tell if a Camaro, Corvette, Chevelle, etc. had a high performance engine in it since it was not in the VIN.

W/o property documentation (original window sticker, tank sticker on '67-71 vettes, protecto plate) one way of determining the real deal is having the #s matching BORN WITH engine (i.e NOT a re-stamp).

For all other cars, with the engine type/size in the VIN, it's not of huge importance of having the "#s matching" engine.

Maybe if you have a CSL, it would be a nice bonus to have the #s matching block, but even then, you can tell it's a CSL w/the VIN.

I say, keep the block in the shed (grease up the journals, bores) and use the ready-to-run "big block".
Click to expand...
All this numbers matching BS nonsense on the SL forum has been giving me conniptions. Immediately after my intro post a guy sets in on me asking why I'd ever consider modifying an original car . . . . .

These guys spend more time fussing over whether their muffler has squared or rounded edges than driving their cars. It's collective insanity, goaded on by whichever OEM's CCA. There's a tiny number of people who care, then everyone else makes their choices trying to cater to those people, who are unlikely ever to see their car, but a potential buyer might be just as well worried about what the originality nazis think. A dear friend of mine a few years ago was selling his 356 Speedster. It had a carrera-swapped motor, which had been done in the mid/late 50s by the original owner. I believe Porsche also offered such an option from the factory. This was apparently a somewhat common thing to do, as the old timers I've spoken to often derided the stock speedster motor as underpowered. Anyway, he kept having people come to give him grief (the man was in his 80s... these were "collectors" in their 40s and 50s) about the "unoriginal motor". Just drive the car, man!

As an aside, evidently if one wants truly top dollar for their E9, it seems it better be modified/swapped/customized in some way, like that amazing M90 build that sold in the 200s last year or the year before.
 
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