2.0 rebuild ?

[Walko]

I am about to go racing and need to rebuild the 69E MFI motor.

I need some input as to the best way to increase HP without increasing capacity(class rules)

My plan was
1 Higher CR
2 RSR sprint cams/ GE80
3 Shorter ratios in the G/box
4 Carillio rods
5 headers
6 Twin Plug
7 piston squirters??
8 TI valve spring retainers etc
9 Rebuild MFI pump and stacks to "S" specs


Does any one have any further ideas.

car will only be used on teh track and is already as light as I can get it.

Michael

[camgrinder]

The RSR sprint or GE80 cams might be too much for your 2.0 litre.
If you get as high as 11.5-1 the RSR cams can start making power in the 6200 range and up , the GE 80 about 6000 and up. Depending on where you race, your gearing etc, you might be better off with a GE60 style cam. With the same compresion the engine will make power around 5000 or 5200 rpms and up. If you have some slow speed corners where you race the bigger cams will force you to down shift more.
The GE60 style cam will be like night and day from your E cams.

[Walko]

John,

thanks for that I planned on having a very short box for the technical tracks and a bit longer ratios for teh HP tracks ie the ones with really long straights.

I was hoping to allow it to rev to 8K or more

Michael

[camgrinder]

Ah ok, if your looking for up to 8000+ rpms go with the 80 profile.

[ErVikingo]

Walko,

GE80 or another 906 derived cam, twin plugged + ported 69 S heads, Weber/PMO 46's, Ti valve train, IMHO not Carillos but Pauters, old style steel studs or ARP's, piston squirters, boattailed case, knife edged crank, turbo or better oil pump with bypass mod. Pistons at 12.5 to 1 or 13.5 to 1 (Cosworth, JE's or?). I use Electromotive for the ignition but you could do MSD which is more reasonably priced.

Useable power band will be around 6200-8000 but what a punch!!! Gas, 110 octane leaded......

[BURN-BROS]

Michael, excellent choice! I am sure you will have great fun.

[Plavan]

Since you have a 69 mag 2.0l case you need to have the bearing machined in (the 1969 2.0L cases do not have this)

[ErVikingo]

Good point Chad!

[Walko]

Any other bits I should add.

Michael

[cnavarro]

I know we've spoken before about your build Michael and possibly changing out cylinders, but maybe Nickies? Weight reduction is nice, but you'll have more dense intake charges than you otherwise would with cast iron cylinders or birals. We've seen 15% more HP when switching to Nickies from cast iron and biral slugs. Not sure of the rule limitations though, but I would guess by the amount of other changes, that it should be good.

I would also recommend putting in the piston squirters, as it will help keep the temperature down and hopefully keep the pin and pin boss in and attached to the piston longer at those RPMs. When ordering your pistons, reinforced skirts, forced dual pin oilers, and split oil return would be nice options to add to the JEs. Some thinwall .120" tool steel pins, although a little more expensive, will offset the weight of the reinforced skirts (they help keep the pin bosses in the pistons @ high RPMS and also support the skirts better). Running the JEs in a set of Nickies would also help by keeping the clearances significantly tighter than in a set of cast iron cylinders.

[ErVikingo]

I think the nickies would be allowed and you also get the better cooling with them !

I must get me a set for next go over.

[Walko]

Thanks for all your input.

I look forward to posting pictures through out the rebuild.

Michael

[snowman]

I don't know why anyone would recommend ANY rod over Carillos, ecxept for cost reasons and then it may be a false echonomy. If your going racing go with Carillos. Ask the people who have been vintage racing for a couple of years what rods they are using, the ones who havn't had any engine problems that is. Out of all the dollars you are spending its only a few hundred more for the very best. Thats unless you can come up with some original factory Ti rods, but the price.. well if you have to ask forget it.

[ErVikingo]

Some of my vintage racing friends have had some bad experiences with the Carillos. Not sure the specifics though

[jluetjen]

The subject of rods for 66 mm stroke engines has been covered before in this thread

A couple of questions back to Walko which might help focus his list of "to do's" a little better:

1) What are you planning on for a rev range? Pick a 2500 RPM range where you plan to have the motor spend most of it's time when on the track.
2) Related to the first question: How long do you want the motor to last between rebuilds?
3) How much do you want to pay for fuel?

[Walko]

To answer the questions.

I don't care where the motor is in the RPM range as long as I am making the most torque and Hp I can.

The gear ratios will be set up so there is 1000rpm drop between 1&2 and then 800rpm between the rest of the gears.

My aim is to have a top speed of 240KMS approx 140MPH.

I figure that as long as I keep the service up to the motor it should last at least a season if not two.

the track events are three 8 lap races approx 6 to 8 times per year.

Fuel will be avgas ie 100plus octane

Michael

[ErVikingo]

Michael,

I've run a lot of gearing combiantion simulations and your description is very optimistic unless you are planning to run really tall 1st and 2nd gears.

Let me know the powerband you are looking at and I can give you some ideas on gearing!

[snowman]

Originally posted by ErVikingo
Some of my vintage racing friends have had some bad experiences with the Carillos. Not sure the specifics though

They never are because it probably was something dumb that they did to cause the failure.

[Walko]

1st and second gears will probably be a bit taller than most people would recommend.

I am planning on working out the 5th gear ration and then work backwards. to ensure the rpm drop works.

I know that this will probably give me a disadvantage off the start line but I wol drather come off the line slow and not run the risk of breaking the gbox.

The class that the car will run in has 302 mustangs etc so I do not expect to be at the front unless we get longer races. In the short races the big V8's brakes and tyres wont fade. I think that any race over ten laps the V8s will have a problem and I hope the little porsche might show them up.

Michael

[snowman]

Walko,

THe most important thing for gearing is which track is it going to run on. Ideally you should have a set of grears for each track, but most of us have to settle for what works best on the largest number of tracks possible. There are 3 basic tracks to consider, short tight tracks with low top speeds, medium tracks with some 100 plus MPH speeds, and long high speed tracks with whatever speed your engine can support, ie 150 MPH for slow cars and 200 MPH for faster ones. Most of us have to live with the medium and short courses so we can usually leave out the tall gears for over 145 to 150 MPH. Next specific track info is really required for any honest gestimate of gears.