2.7 Rebuild options?
 

Getting ahead of myself but I am curious since I didn't have any luck in my search but trying to learn more about 2.7 rebuilds.

Was reading Bruce Anderson's book and he suggested two options for rebuilding a 2.7.

1) 95mm Euro RS p&cs, 911E cams, and Weber 40IDA carbs. OR

2) replicating an RS engine. So if I read right, basically, going Carbs or MFI?

Priceout:
95mm Euro RS p&c - $5K
911E cams - $2K
Weber Carbs - $4k
MFI Pump - $4K?


I'm just curious what the cost/benefits of each.

***if this has already been discussed, someone please direct me to the thread***

It’s hard to throw enough money at a 2.7 mag case because you’ll be into the SC costs and never reach the value of the aluminum motors.
Option, 2.8 and JEs 9.5/10.0 cr
Solex grind cams and some carbs
Bruce

I didn't know you could go to 95mm pistons on a 2.7 case. I have a 2.7 w 90mm 9.5:1 pistons, S cams, Webers that was really nice 'til it spun a rod. It was a reasonably priced build. Mostly parts from forum, swap meets, etc. MFI can get expensive and isn't very tunable. S cams are peaky, but the displacement of the 2.7 still makes ok power down in the rpms. A 2.0 with S cams is downright gutless until 4.5K RPM, but the 2.7 is comfortable in traffic. Dougherty has the DC-40 cam that is supposed to have a flatter power curve without much top end loss. I might try that when I rebuild it. A few other cam places have something similar. Solex or E are decent too. Check the forums.

Do the slot and cross drill on the center main of the crank if you have it out. Much better oiling for middle rods.

Good luck.

I've built both of these and they are great combinations with very similar performance. Couple of thoughts:

As above don't skimp on having the case work done.

40 idas will end up significantly less expensive than putting all of the mfi parts together.

Overall performance will be very similar, mfi will be a little "snappier"

40idas will allow you to less expensively aoccomodate more modern cam profiles. GE or DC profiles.

You also need to add 73 and prior heat exchangers to get the performance too.

As mentioned, the 2.7 mag case engine is a machine work specific build. Heat is the killer. Mag case engines (75-77) US cars came from the factory running way too hot. Case savers, line bore selective 8 mm perimeter bolts are all good ideas.
As for the build, you don't want to spin the 2.7 engine so built as big as possible. As mentioned above, 2.7 cases generally have a 93mm build limit.
Supertec has a special cylinder manufactured in house that will allow the use of a 95mm piston. I don't know of any other manufacturer.
Producing a functioning MFI system is a $10-15K proposition. not $4K.
Good carbs can be picked up cheap but if they need work that can easily cost $ 2,500 on top of the purchase price.
If carbs are your final choice, I like the Solex grind or Doughtery's Mod "S" grind.
Keep in mind, heat is a challenge in most 2.7 builds. Front cooler is a must if your plan is spirited driving with more than 165hp.
A 2.7 (3.0 if you use our cylinders) with 9.5:1 compression will produce 200hp+ so cooler is mandatory. If you are unsure about octane in your area, lean closer to 9.0:1 especially if you choose the Solex cams.

http://forums.pelicanparts.com/uploa...1758551154.JPG
http://forums.pelicanparts.com/uploa...1758551154.JPG

I’m intrigued how 95mm pistons fit cylinders that slip into 97mm case holes without weakening the case land too much … I trust if Henry says it’s a good solution .. but don’t get how it fits

I have built a 10.2:1 Mod-S MFI engine. It does seem to be a peach.

The 2.7/95mm cylinders are bore in. The 7R case has a flange of 109mm and the cylinders are 98.75mm. That leaves a mounting surface of 5mm. That is more than enough surface area to offer the stability necessary for 250 hp.

Thanks for all the responses, very interesting.