2.7 litre

jacksonpinz · Post by **jacksonpinz** » Sat Mar 31, 2007 9:06 pm

I have now had the Pinz a few days and can tell I am really down on HP at my altitude. I down to about 71 from 90. My 712 struggles to maintain 55 mph and I do not like flooring the rig to maintain that speed. I really like the Stery engine as the torque is amazing. I am considering changing it to 2.7 Liter. I have been told that some of you have done this and know where to get pistons and rings for the bigger bore. I also am considering a cam as a little more lift might help it breath a little better at my altitude. If I had the original 90 hp I would leave it alone. If I go to say 9000 ft, I will be down to 65 hp. I know Pinz's are not suppossed to be fast, but I would like to cruise at 55 without blowing the engine.

Another option, but I have not really though about it, would be a very small supercharger. Intercooler would be a serious problem, but the condensed air at my altitude would really help. Anyone ever explored this option, or even turbocharging

I know final numbers are not out on the EFI, but any vehicle or boat I have seen switched to EFI usually picks up about at least 10% more power as well. I have some pretty good knowledge on tuning EFI systems. I am thinking start with the bore and then perhaps add this system when ready and I should be back in the game. Any help would be appreciated.

todds112 · Post by **todds112** » Sat Mar 31, 2007 9:19 pm

John, Did you get the main jets switched out to 125's? I noticed a bit of an improvement in mine after switching them out. Of course it's still no race car, but it will keep up with my girlfriend's KIA

.

jacksonpinz · Post by **jacksonpinz** » Sat Mar 31, 2007 9:56 pm

Jets are on the way. It is definetly a little rich. Hopefully they will be here by Monday or Tuesday. It runs really well, just down on power. Went through this with three boats as well. Ran great at sea level, bring them up here and they hardly planed. Took re-proping, gears, etc.. to finally get them to perform somewhat.

todds112 · Post by **todds112** » Sat Mar 31, 2007 10:03 pm

Come to think of it I don't run so good (current injury notwithstanding) since I came up here from Ohio (900' to 7000'+).

Wonder if I can be re-jetted??

jacksonpinz · Post by **jacksonpinz** » Sun Apr 01, 2007 9:15 am

I think you need more than that! Great weather today for working on the Pinz. I played hookey yesterday and went fly fishing on the Snake.

Linden Engineering- I was looking at your website. Do you offer pistons and rings for a bigger bore Pinz engine?

ExpeditionImports · Post by **ExpeditionImports** » Sun Apr 01, 2007 9:53 am

Quite a few of the Pinz suppliers/repair shops have their version of a 2.7/power upgrade. Definitely jets are going to be your first step. If you decide more power is needed keep in mind the following:

Most of the 2.7 power increase does not come from the increase in displacement, but the increase in compression. For example our kit with Ross pistons increases the compression from approximately 7.6 to 8.6:1

Definitely consider a Cam at the same time. A custom ground cam can make a world of difference with a 2.7L.

With the 2.7 your carbs will need to be re-jetted. Here at sea level the 2.7 usually neccesitates main jets in the 165-170 range. An analyzer is the only accurate way to verify....well worth the extra $100 to find a shop with one if you don't have one.

Prices will vary, but we have found the 2.7 is usually cheaper to upgrade than a stock rebuild. For referrence our kit currently runs $1650 for:

4 Custom Ross High Compression Pistons
4 Sets Total Seal Rings
4 Wrist Pins
4 Cylinders - Bored and matched to the pistons. (We will need your old ones back)
Top End Gasket Kit for Assembly

Add $325 for a cam - (exchange basis)

Cheers,

Scott Ingham

todds112 · Post by **todds112** » Sun Apr 01, 2007 6:34 pm

Scott, does this upgrade necessitate new heads, valves, etc? That seems very reasonable. Does the increase in compression pose any risks (blowing head gaskets etc)?

Just wondering when/if it comes time for a re-build, it would seem silly not to upgrade for less money.

Profpinz · Post by **Profpinz** » Sun Apr 01, 2007 6:44 pm

(blowing head gaskets etc)?

What head gaskets?

todds112 · Post by **todds112** » Sun Apr 01, 2007 6:46 pm

Profpinz wrote:
(blowing head gaskets etc)?
What head gaskets?

Ooooops.

ExpeditionImports · Post by **ExpeditionImports** » Sun Apr 01, 2007 11:36 pm

Your stock heads are fine, although a rebuild at the same time would be in order. By keeping below a 9:1 compression we are making sure that you can continue to burn Regular unleaded. As mentioned, there are no head gaskets hence the need to make sure your machinist knows EXACTLY what they are doing when they fly cut the mating surface.

Like I said, we have been very happy with the performance and cost/benefit of going to the 2.7 I have yet to have a customer who would prefer to pay more money for a stock rebuild when the same reliability can be had with an added power increase....for less money.

Cheers,

Scott

todds112 · Post by **todds112** » Sun Apr 01, 2007 11:41 pm

Sounds like the way to go when rebuild times comes.

I know with the Jeep I-6's going to a "stroker" 4.7 seems to create a whole new can of worms. Still learning this air-cooled technology.