engine and drivetrain UPDATE: 2010-07-29 serious questions for engine builders

[M3M3]

whoa....grice....

you have mentioned "club racing" several times now. you need to be completely clear on what you intend to do in that venue. if you are really truly going to attempt to get your racing license and compete, that completely changes the approach and your engine options. a club racing car is not something you can easily or safely drive on the street. got a truck and trailer?

yes, i have seen street legal "race cars". but i have never seen one that is even remotely competitive in a race. and have no doubt that if you do start racing, being competitive will consume you. nobody wants to run at the back of the pack.

the big thing though is that you MUST PICK WHAT KIND OF RACING YOU WANT TO DO BEFORE YOU BUILD AN ENGINE! every sanctioning body and class has rules. pick the class and sanctioning body you intend to race with. get the rule book. read the rule book. study the rule book. talk with others already in that class. then, and only then, start designing and building your engine to meet the rules. if you just build what you want as you have defined in this thread, you will have no legal place to race the car.

btdt. have the race cars to prove it....;-)

[jgerock]

I've had good luck with Centerforce clutches for street and autocross use. Haven't broken one yet, and not for lack of trying.

+1 on the Centerforce brand of clutch disk. I have a CF dual-friction disk in my VW that grips well but doesn't hurt your leg to push on the clutch pedal.

I'm watching this thread closely - as Grice and I discussed this a little last Saturday.

[BigDog]

Looks like fun, a couple quick comments...

Cometic head gasket, probably overkill, but on the other hand, why not? Just remember you'll have to get the head decked appropriately (don't forget to include the front cover). The cometic gaskets are thick so in order to not loose compression, you'll have to deck the head, not sure how much, Ireland probably knows, give them a ring.

Eurothane engine mounts are great, but if you combine them with eurothane tranny mounts you'll find it's a bit too much in terms of vibration. Reccomend new stock mounts for the tranny and eurothane for the motor.

BD

[Jim_75Sahara]

I know very little beyond what I've recently picked up w/an engine rebuild. Mine is bored out & has piano-top pistons with a 9.5 : 1 compression ratio. It was recommended to me (no track time planned, no racing) to keep the orig. cam & to leave the flywheel alone. That's just me. The orig. equipt. is v. good unless you are going for something a lot more aggressive? Of course, I very badly wanted a 5-speed, but that was a $$ issue. Good luck.

[williamggruff]

Marshall,

Many thanks for your comments. It appears I'm using improper terminology here. By "club racing" I'm referring to non-sanctioned events that don't require the full SCCA inspection--e.g. no fuel cell, cut-off switch, etc. I intend to pursue a race license, but will take that step by step, keeping in mind that I'll need a budget for a competition-specific car, trailer and hauler, race fees, etc. when I do so.

I'm looking to have a car that can be driven (though not necessarily comfortably) on the street, and used on the track at HDPE classes and in weekend lap sessions to learn and hone skills as a driver. I was under the impression that there are occasional opportunities to engage in limited competition during weekend BMWCCA events on tracks in the region. Perhaps I've misunderstood the way this works.

I don't have any illusions that a street legal car will be competitive in league racing, and I'm not interested in nursing an illegal car around on the street in order to avoid buying a trailer. I expect the car will be uncivilized, but street legal, and a hell of a lot of fun if I put the correct parts together.

After two motor disasters in a row, I'm torn between the off-the-shelf motor approach suggested by Nick Vyse and the custom-built motor I've described above. I've spent several months poring over offerings from Metric Mechanic and Korman and pricing out parts from a variety of vendors in an attempt to arrive at comparable solutions. It seems that I can buy some well-engineered parts, get the machining done by local shops, and assembly performed by an engine builder for about the price of a Metric Mechanic low-end motor. That said, I'm not sure I'm gaining or losing anything by going either route. I can be very picky if I choose the parts individually, but I'm taking a risk on the final assembly. Metric Mechanic adds their own improvements that they've researched and tested, and I can't reasonably expect a local engine builder to match Metric Mechanic's results with head porting or other innovations.

The head scratching continues...

[jgerry2002]

I'm looking to have a car that can be driven (though not necessarily comfortably) on the street, and used on the track at HDPE classes and in weekend lap sessions to learn and hone skills as a driver.

I've spent several months poring over offerings from Metric Mechanic and Korman and pricing out parts from a variety of vendors in an attempt to arrive at comparable solutions.

BMWCCA HPDE? 2.2L is fine, you ain't gonna be the fastest one out there, but you'll be having the most fun. You can get away with 6500 rpm shifts just fine and not abuse anything. A mis-shift of 8k? that would be a nasty mis-shift.

Also, If you are serious about moving up into club racing get a E30 or newer.

Also its an old car, so you are going to have to stay on top of everything else that breaks and likely freshen up other parts that you'd typically leave alone in a newer car. Figure on some mileage/time on the street to sort everything out. Its inevitable things will break/need adjustment, especially anything custom.

I have two cars with Metric 2200 hiflo motors, very very good motors for the money. I've had no issues with them to date.

Of course YMMV.

[FB73tii]

Hi Grice,

I run lash caps on my Norris 301 as well, as the base circle is not stock. The lift on your 305 looks about halfway between a Schrick 304 and 316, though other specs will be different. Should be a very nice cam. My 2002tii puts out 140-150 HP at the crank with just 9.5:1 pistons and the Norris 301. At 2000 lb dry, full cage, and a 4.45 diff, it is quick and fun in the corners. It lives between 4500-6700 RPM most days, sometimes up to 7000. Seems to be fine with stock rockers. However, my current setup would not be competitive in BMW CCA club racing, which is why I am building a 2.2L full-race 13:1 dry sumped engine to run in E-Mod. The kind that needs to be rebuilt every season or so.

Knife-edging the crank should be good. I too will be using the Isihara-Johnson scraper, looks like a nice piece. Dry sump not necessary for a HPDE track car, just wanted to mention it in case you were so inclined. I will run about 10-12 inches Hg on mine with a sealed engine, should be good for a bit of power and excellent oil control. You should be fine with your baffled pan. I use IE's fixed baffle in my current car, never starves in corners. You may want to add an accusump. An oil cooler is key for track work in warm climates (DC/VA summers), I use a 19-row Moroso, though I had a 16 row previously that did just fine. My Ron Davis radiator keeps the water cool on even the most demanding days.

I would think IE's solid puck clutch would be fine on the street, unless you do a lot of stop-and-go driving. However, I could be wrong. The positive response is very nice on the track. Nowhere near as harsh as a 5.25" multi-plate ($$$) racing clutch.

You probably don't need ARP fasteners for your engine, I don't have them on my current engine. Then again, if the budget allows, why not? As to purchasing a "turn-key" engine versus a custom engine, I decided to go the custom route some time ago. I have spent about 1.5 years on research, talking to many experts, and reading everything I can. I prefer to understand exactly what I have, why I have it, and how to maintain it.

Best,

Fred

'74tii

[Tommy]

... May I ask what was the type of failure you experienced?

...

Regarding the timing chain gear, would you recommend a single or double row gear and chain?...

My friend lost whole engine because of the pads on rockers suddenly wore out. Metal was everywhere. Mine have already started to wear. Both were from Skidmarks last serie, which was supposed to be good. These were the style with eccentrics. Another friend lost the adjustment pieces from Ireland rocker, the current style with different adjustment.

Some say that the single row chain is stronger one. I don't know. I have used double row. There's very little trouble with them. I actually haven't ever heard a chain break from m10. Use new oem parts.

You mentioned mechanical timing chain tensioner. I prefer original spring with oil damping but I have made mechanical limiter that stops the piston after few millimeters. Once, in another friends engine again, the tensioner piston separated in pieces because the mechanical stopper pushed the inner part of piston out from outer part. After that I made small welds to make sure that the piston stays in one piece.

I like your style to plan ahead and I'm glad if I can help some.

Tommy

[M3M3]

Marshall,

Many thanks for your comments. It appears I'm using improper terminology here. By "club racing" I'm referring to non-sanctioned events that don't require the full SCCA inspection--e.g. no fuel cell, cut-off switch, etc. I intend to pursue a race license, but will take that step by step, keeping in mind that I'll need a budget for a competition-specific car, trailer and hauler, race fees, etc. when I do so.

I'm looking to have a car that can be driven (though not necessarily comfortably) on the street, and used on the track at HDPE classes and in weekend lap sessions to learn and hone skills as a driver. I was under the impression that there are occasional opportunities to engage in limited competition during weekend BMWCCA events on tracks in the region. Perhaps I've misunderstood the way this works.

.

you will find that there are no un-sanctioned competition events. you need to get racing lic and then compete with NASA, VARA, SCCA, BMWCCA, etc. if you race, you will have to get into roll cages, harnesses, rules, window nets, etc.

build it up like you want it and do HPDE's with various organizations for a few years. SCCA has track time trials when you get to that level of HPDE. basically timed laps on a track. when you get to the point of actually wanting to race, then get a different car...an already built 2002, e30 or e36 race car.

i instruct hpde's and competition schools for SCCA. happy to have a 2002 student later this summer! i can bring mine for the instructor sessions.

[TobyB]

So just to add my 2c to the fray-

I agree with Tommy almost completely.

Especially about the head gasket- stock is just fine

to 11:1+, and the Cometic is not necessarily the best for

an aluminum/iron engine. Cutting ring is also fine, especially

for a motor that won't be coming apart very often. I don't use them

but then, it seems like the head's off the car every 2-3 races.

A question that really defines everything else-

how many revs do you plan to use???

Here are the limits I've found, with a cam not too dissimilar from what you

propose:

up to 6500 rpm- stock everything.

up to 7500 rpm- uprated valve springs (Ireland racing or similar) and a 228mm clutch (215 mm pressure plates fail)

8k- uprated rod bolts (which means new rods, really)

Over 8k it's time for steel rockers and even stouter valve springs.

But all your wear parameters will skyrocket from here on up...

I run uncoated bearings. Seem fine.

I DO run an Accusump. It's cheap insurance. Especially at Portland,

you can watch the car use it 4 or 5 times a lap. And if you run a bit low

on oil, it will save your motor. You have to be careful not to overfill, tho.

Thoughts about engine prep- if you do go to 10:1, you'll need good spark

control, fuelling and tuning. That said, you can do it.

If you want a good 'learning' engine, don't spend too much on stuff like rods-

a nice 9.5:1 motor will last a long time if you take care of it, and you can

learn a lot about everything else as you go. That's how I did it.

Especially if you want to start doing the lapping day circuit- you want

a car you can count on 100% so you have free brain to learn how to

drive...

As to starting on a track- addict path, start with a mostly- stock car.

If you build a 9:5, 140 (ish) hp motor, just build a mild chassis to go with it.

ST springs, Bils HD's, ST bars and uprated brakes are a fine starting place.

It won't be bad to street drive, and it will teach you a ton.

Start with high performance street tires. They're very good, but they

have more safety built in...

that's what I think.

t

[williamggruff]

Toby,

As always, your comments are much appreciated.

I plan to use some serious revs, which is to say I expect that I'll over-rev the motor during downshifting while learning to work the car on the track. It seems advisable to plan on failure rather than fail on planure. That's not really working English, but I think you get the point. I'd rather aim for a bulletproof motor at a slightly higher cost with slightly lower output than aim for short-lived insanity. Long-lived insanity is definitely more my style.

The rest of the car will be pretty much the way you've described: Billy sports and H&R springs front and rear, ST sways, KMAC adjustable camber front and rear, standard big brake kit up front, 320 drums in back, .391 LSD, 5-speed. Decent street tires will go on once the car is running later this summer.

The car will likely be a bit uncomfortable on the street, especially if I install a 6-point roll cage and require the use of a helmet for my passenger. I have a bolt-in cage, but it's not going in the car unless it's welded in place and covered in foam. Though it'll add some weight, it'll probably come in handy in the DC/MD/VA area, and it'll certainly be a good safety feature for the track.

Grice

[TobyB]

I think you'll be happy with what you're proposing, Grice-

I'd set your rev limiter at 7250 and save a bunch of money,

'cause you'll still get tons of fun out of that package.

Suggestion- keep a stock (ish) interior and the dash to start.

Then you won't scare people (instructors) at the track for lapping

days.

A roll BAR isn't a bad idea, and some cage kits are adaptable to

just use the back 4 points. Then you get real rollover protection

and a regular car in front (no, it's NOT a mullet, dammit!)

But I'd hold on the cage for now.

There is NOTHING wrong with a well- done bolt- in. Autopower is

not well- done. You need nice, big pads, and proper attachment with

well- bolted full- sized backing plates.... you'll get darned close

to a weld- in...

t

[Tommy]

I think you'll be happy with what you're proposing, Grice-

I'd set your rev limiter at 7250 and save a bunch of money,

'cause you'll still get tons of fun out of that package.

Second this. That's just where it gets expensive and STILL loose reliability. The engine will still take some downshifting mistakes without problem. It's the continuous high revs that fatigue the rockers. What it can't take is that you accelerate 3rd to redline from corner and shift to 2nd instead of 4.

Tommy

[williamggruff]

Many thanks to one and all for the helpful feedback, comments and questions. I'm preparing to pull the trigger, but have a few remaining questions regarding the details. I have no brand loyalty, and few preconceived notions regarding manufacturers or vendors (with the exception of BLUNT, of course), having never bought, tested, beaten or broken many of the parts that I'm going to be buying for the motor. Any experiences and/or insights you can provide will be greatly appreciated.

I note that both IE and Korman offer upgraded rockers, and I suspect there are others out there that I simply haven't found. I'm hoping to learn what's on the market besides IE heavy duty rockers, and how those other offerings compare for strength, durability, weight and mass distribution.

Same question regarding rods. IE offers a set of H-beam rods that they claim are lighter and stronger than stock. What else is available and how do they compare?

Same question regarding valve springs. Top End offers dual valve springs, as do IE, Schrick, Korman and a few others. Some of these folks offer heavy duty single springs. Which of these would be most appropriate (compatibility may be an issue) given that I'm planning to use a Norris 305 with max valve lift on intake of 0.441 inches (11.2014 mm) and on exhaust of 0.447 inches (11.3538 mm)? More detailed specs on the cam are provided in the attached PDF. The Norris 305 is the first set of specs.

Finally, same question regarding pistons. There are many offerings out there. Forged vs. cast? Treated skirts or not? Are there specific qualities that I should look for, and others that I should avoid? Do you have a preference for one manufacturer over others?

Grice

[TobyB]

Honestly, with that cam, if you do keep it below 7500,

(and there won't be much power above)

start with Febi. Buy 16, keep the best 8, and you're out less than

one Lester Owen rocker. I finally went to the Ireland HD aluminum

version, and for $200, they're ALSO less than one steel one...

You really don't need anything stronger, and as Tommy noted,

metallurgy will get expensive if a custom rocker decides to abrade a cam.

And stock rods, just because until you really decide to build a 10k grenade,

they'll be OK. Carillo, Pauter, etc all make one that works-

and yes, they're good, but your cam isn't gonna make the flow that

makes spinning that fast necessary. Ireland rods use M3 bearing shells,

and that makes them even more expensive.

Springs- well, you'll want #110-120 lbs on the seat, and 200- 250 on the nose.

I use the Irelands, but any of them will work. DO check to make SURE they

don't come close to bind, as that will pop rockers like no- ones business.

Pistons? If you're willing to wait for it to warm up before you drive away,

forged are probably good for your application. I've heard no horror stories

about any of the reputable makers, and if you do want to get a bit fancy,

talk to Jeff Ireland about moving the pin up in the piston and using a longer

rod.

DO look at what ring package they use- the Ross, at least, use a very light, tight

package that is very low drag- but not as durable as stock.

hth,

t