U.S. and Euro 3.5 conversion

Knowing what I know now and if I had to do it all again, I'd start with a ater B35 and build up from there. As SFdon said, you get the higher compression along a better breathing head with larger valves and double springs. After that, its really a budget thing how far you want to go, i.e. exhaust, injectors, porting, megasquirt, etc). The easiest thing is to throw a cam at it and call it a day in a coupe though you may need some sort of fuel management to really get it dialed in right or at the very least, maybe a bit higher fuel pressure and/or a good after market chip from someone like Mark D'Sylvia. You will feel a difference. Next, consider a lower ratio LS diff like a 3.45 or 3.64 but know that your engine revs will go up and your mileage will go down especially on the highway. Beyond that, a coupe requires, I think, more chassis strengthening along with fresh and tight suspension and brakes.

For those of you with B34 M30s, Paul has cams for those as well (I have one) which he swears is comparable to but more refined than the Schrick 284. The B34 heads have single springs in the head so I am not sure what his recommendation is.

For real HP, you need to go Turbo as Coachkel says and Todd Dehate of TCD fame has the goods if you want to go that route. I didn't want to go turbo for a variety of reasons so I did the (over the top) custom build instead. Its plenty powerful enough for me as I can give the lighter turbo'd cars a good run. I can't imagine what the performance is like with boost in the double digits though I'm sure I could probably get used to it.

So lots of options whether you start with a B34 or B35. Just make sure that you start with a lump in good condition before you start your build.
 
and another thing

I think the B35s come with Motronic v1.3 so if the intention is to stay in the motronic "family" this is better than v1.0 that's on the B34. Its somewhat adaptive so it might "learn" to work with a cam though I'd still get the chip from D'sylvia. He might even customize it for the cam.
 
After a very informative call with Paul Burke he suggested I start with a B34bottom because of the simple install. Bore it to support his pistons and use the rest of my B35 donor and his cam.
 
Get our your wallet ready :). Mr Burke is an excellent builder, and an even better salesman. Get yourself an early b35 motor (88 735i or 88 535i) as SfDon suggested and call it a day. The amount of money you'll spend on buying custom pistons and doing a full build won't be worth it. I know as I lived in the dyno shop. I can't tell you how many customers I saw disappointed after they thought they would have a lot more hp than they actually did. Unless you are going to run 11:1 comp, run a radical cam, and replace the rockers, etc, I'd just find a good early b35.

bwalvoord said:
After a very informative call with Paul Burke he suggested I start with a B34bottom because of the simple install. Bore it to support his pistons and use the rest of my B35 donor and his cam.
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Get our your wallet ready . Mr Burke is an excellent builder, and an even better salesman. Get yourself an early b35 motor (88 735i or 88 535i) as SfDon suggested and call it a day. The amount of money you'll spend on buying custom pistons and doing a full build won't be worth it. I know as I lived in the dyno shop. I can't tell you how many customers I saw disappointed after they thought they would have a lot more hp than they actually did. Unless you are going to run 11:1 comp, run a radical cam, and replace the rockers, etc, I'd just find a good early b35.
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Everybody has their own motives and budgets for motor builds. My experience with Paul (a B34 custom head build) was all good. He sourced a used head (took 3 tries to meet his spec) and then built the head for me which involved some custom milling. He turned the whole job around in 3 weeks and shipped it to me with a headgasket for about 2/3 the cost I was quoted for a stock rebuild with me supplying the head. Paul's prices, in my experience anyway, was very, very competitive especially for the quality you get. With regard to performance, my dyno results actually exceeded what Paul estimated. His main challenge is that he has too much work and not enough time.

But to your point, an engine build can become a slippery slope. Its easy to get trapped by "while you are in there..." type add ons. Ask me how I know. The prudent approach, as you suggest, would be to source a B35 and throw one of Paul's cams at it, stick with Motronic v1.3 and a chip and call it a day. But its hard to be prudent sometimes. That's part of the fun.
 
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A good builder will always tell you a conservative hp number to expect. If you don't people knowing on the board, what did you spend in totality on your custom build?

TodB said:
Everybody has their own motives and budgets for motor builds. My experience with Paul (a B34 custom head build) was all good. He sourced a used head (took 3 tries to meet his spec) and then built the head for me which involved some custom milling. He turned the whole job around in 3 weeks and shipped it to me with a headgasket for about 2/3 the cost I was quoted for a stock rebuild with me supplying the head. Paul's prices, in my experience anyway, was very, very competitive especially for the quality you get. With regard to performance, my dyno results actually exceeded what Paul estimated. His main challenge is that he has too much work and not enough time.

But to your point, an engine build can become a slippery slope. Its easy to get trapped by "while you are in there..." type add ons. Ask me how I know. The prudent approach, as you suggest, would be to source a B35 and throw one of Paul's cams at it, stick with Motronic v1.3 and a chip and call it a day. But its hard to be prudent sometimes. That's part of the fun.
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Prudence went out the door after the new head arrived from Paul and quickly extended into a Miller programmable war chip, MAF, bigger throttle body, larger injectors, larger coil, a header with custom exhaust. Lots of sorting time and research which in foggy hindsight, was fun most of the time. Frankly its a number I don't want to add up but it was part of the "learning experience".

So north of $3K just in parts for the items mentioned above (the head and used header being 3/4 of it). Fiscally responsible and could I get my money back? Absolutely not but I'm thrilled with the result and got exactly what I wanted. Sometimes passion overrules logic.:shock:
 
paul cam and war chip

hi tod,
ive got a cam from paul coming, and i too have the miller war chip and maf (but with b35), and am wondering about how you changed the war chip tune after cam?
tia,
alanmcg
 
Alan, you need to contact Miller, they keep dozens of tunes that might fit your hotter cam. You won't be the first who has added a hot cam to a b35 and run the War Chip. Brody will probably have something to get you going, but most likely you'll have to get time on a dyno with an experienced tuner.

Todd, back to your build. Many guys choose the slippery slope...it can be a lot of fun. My point to bring it up is this; most who think they will build a custom engine usually end up shelling out a lot more than they first thought, but thats why it needs to be fun as the dollars begin to burn holes in the pockets :mrgreen:.
 
most who think they will build a custom engine usually end up shelling out a lot more than they first thought, but thats why it needs to be fun as the dollars begin to burn holes in the pockets .
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Agreed. For me, it was a design/build as you go project. If (when?) I do it again, I'll now better what I'm getting myself into and can hopefully plan the project and budget better ahead of time and limit the surprises.

Alan, as Coachkel says, Brody will have a map for you to start with that should get you 90% there that incorporates Paul's cam and their MAF (Paul supplies his cams to them). Before you do anything, make sure all of the ignition and fuel delivery are in tip top shape. After the install, find a long hill on a highway and do 4th gear pulls listening for pinging and adjust the ignition as necessary trying to to get a ticket in the process. Not scientific, but it worked for me. After that, get a wideband or go to a Dyno for an hour (bring your laptop) and get the fuel dialed in. Are you using 19LB injectors or 24s? Mine tended to run past the injector capacity at the upper RPM ranges so I migrated to 24s.

Or just take it to SFDon and have him install MS and get it done right.
 
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I appreciate all of the input from you guys and you make a good point about the slippery slope. For example, why should I powder coat and plate everything if I'm not going to repaint the whole car. No need for the engine to be museum quality if the rest of the car is not.
 
Get a can of wd 40 and a wire brush for all those aluminum intake parts.
 
tod,
my injectors are the bosch/volvo ones cn uses in his 3.5 motronic motors (pic below). re ms conversion, already made this decision, just a question of time (especially as have sven's help and vast experience close by).

you mention below you went to a 'larger throttle body'?? which one did you have and which one did you change to??
 

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I went from a stock throttle body to one that was bored out 3 MM by a guy on the mye28 board. Not sure he does the service anymore but it, along with the larger injectors, yielded 10 HP an 15 lbs of torque at the wheels.
 
Todd. I'm very curious about your stroker motor since I've been doing research to do something similar, even though I'm still extremely happy with my Euro M30B34 1.1 with Hartge headers, which I've adapted a B35 head to (just to try it out for the larger intake valves). How did you get 3.7 liters with b35 pistons? You must have a 90mm plus stroke crankshaft? Also, what valves did you use that are 2mm larger?

Thanks.
 
My motor was originally modded by Dinan in the early 90s with some sort of crank and B35 pistons. The B34 head had to be modded a bit to work with the pistons. I do not have details on the crank. When I spoke with Dinan, he swears that he did not put the pistons in when he did the motor but that was a million years ago also.

The head I have now was built by Paul Burke. I don't know the details about the valves.

So I'm not being very helpful...
 
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