about to push the green button on a rebuild - Any last minute advice?
 

Fellow Pelicanites:

I’m finally fulfilling a dream and am having PPs own Henry Schmidt build/ rebuild my motor. I can’t tell you how excited I am at this and how pleasant Henry is to deal with. He is incredibly patient and informative talking me through all the big decisions. Anything Henry builds I’m sure will be a dream to own and drive.

That said, this is a big expense and one I only want to do once hence I can’t stop thinking if the build we’re planning is really the way I want to go and would love to hear the board’s thoughts/ ideas.

What I’m primarily looking for from the motor is solid low-end and mid-range torque as this will be predominately a street car on roads with a 75mph max. That said, I can’t help but think about losing too much HP at the top end for when I do take it on the track. In other words, I’m looking for that elusive perfect balance between street and play.

What do you think?

Objective:
1. Build from 73.5 7R case
2. 75% street / 25% track
3. Strong torque between 2,500 and 6,000 rpm
4. HP not as much an issue given primarily for street use, but then again…
5. Solid reliability and longevity
6. Better fuel economy (now at roughly 13mpg on 40 PMOs)

The car it’s going into:
• 73.5 t
• All new suspension by FarnbacherLoles (ER Polybronze bushings, new ball joints, 21/27 TBs) and lowered to European ride height
• Mostly restored body though that’s getting a refresher while Henry has the motor

What we’re currently discussing:
• 73.5 2.4t 7R case (car is a 73.5 ex CIS)
• 2.7 9.5 TO 1 COMPRESSION JE PISTONS AND MAHLE CYLINDERS 90mm
• MFI
• DC 24 camshafts
• 2.4 LITER CRANK (MAG AND MICRO POLISHED) 70.4 stroke
• 2.7 LITER OIL PUMP AND PUMP MODIFICATION
• SSI’s
• M&K 2 in / 1 out exhaust

I just noticed I put this on the wrong forum last night. I meant to place it on the engine rebuild forum. How can I move it?

What did Henry suggest? He da man. ;)

If you're talking about 75 MPH max on the highway and 25% track use, you might consider a gear change while you have the tranny out. If you don't mind cruising down the highway at 3,000 RPM's instead of 2,500 RPM's, lower gears will really make your package come alive.
Gears are like magic.

Henry is currently recommending the below based on my objectives. Again, I trust Henry's judgement implicity. My basic question is, what are your thoughts on my objectives? Am I being to practical by looking for mid-range torque only and thereby sacrificing top end speed for when I do track the car (driver's ed only)? I'm only doing this rebuild once and want to make sure I'm not kicking myself later for being too practical now. (Well, technically it will eb teh secon rebuild - but I don't count the MM fiasco.)

• 73.5 2.4t 7R case (car is a 73.5 ex CIS)
• 2.7 9.5 TO 1 COMPRESSION JE PISTONS AND MAHLE CYLINDERS 90mm
• MFI
• DC 24 camshafts
• 2.4 LITER CRANK (MAG AND MICRO POLISHED) 70.4 stroke
• 2.7 LITER OIL PUMP AND PUMP MODIFICATION
• SSI’s
• M&K 2 in / 1 out exhaust

Oliver, Do a search for 'camgrinder' contact him. He's the resident cam guru and I believe the 'DC' cams are his creation. All else looks fine. "MAX 75MPH highway" ;)

My only two comments would be
Listen to Henry and there ain't no substitute for cubic centimeters. As him how much to build one of those monster 3.5 MFI motors.SmileWavy

It looks like a good plan but there is one bit of information missing. What size ports and throttle bodies is Henry recommending? With a 2.7 you can use 36mm ports and "S" size throttle bodies (38mm I think). With that set-up I'd use Mod S cams (DC 40) and stiffer valve springs (from Camgrinder). If you want stock valve springs then solex cams are perfect. You will have as much torque as you can use starting about 3500 RPM and it will pull to over 7000 RPM.

The MFI is a good idea (although expensive). Your mileage should improve quite abit.

-Andy

Suspension: If I was you, I would run stiffer torsion bars than that. I run 22/29 on a Carrera and the ride is comfortable. When I decided to upgrade to the stiffer bars, I was expecting that I'd be making the ride less comfortable but it was fine.

I can hear you thinking "But Chris, a Carrera is a heavier car". A Carrera is heavier in the rear but the front axle weight is about the same.

Motor objectives: IMO, if you can resign yourself to having a little less speed at the end of that long back straight at Watkin's Glen, 99% of the time low end torque will "feel" better than peak horsepower.

-Chris

Thanks for your comments guys.

Eagledriver: I'm not sure what the port sizes are. I'm leaving all that in Henry's extremely capable hands. I would go with Henry's stiffer springs if we go with a higher revving set-up.

ChrisBennet:
Suspension: The 21/27s are already in the car and made a significant improvement over the originals though it's hard to attribute the improvement to TBs alone as I also had all the 30+ year old bushings and ball joints replaced at the same time. All this completely transformed the car. FarnbacherLoles really did a wonderful job.

Motor: you're confirming my original objectives. When I do track the car it has been only at Lime Rock so far (short and twisty with a short straight) and I do plan a few DE's at Watkins Glenn next year. I hope to finally take as much advantage as I can on living this close to two terrific tracks.

So we have one node for Torque over HP.

God be with you . . .

Hey Oliver, I can't opine on that motor other than I didn't notice which turbo you were going with (har), but PM me the next time you're going to track it. I'll join you with the 930. I love sharing the road with that fine car of yours.

Oliver, how did this all work out? Did you get the engine back yet, and what were the final specs on it?
Looking forward to seeing/hearing it.
Karl.