2.5 to 2.7 liter conversion

[totaljoint]

Hi all:
Does anyone have experience with a 2.5 to 2.7 liter conversion in a 712M?

I'm considering the change, but would like to know what others have found with acceleration, top end speed, and especially driving up mountain highways (Cascades: elevation 0-4500ft). Would I notice a big difference between the two engines?
Any downside to the change besides the $?

Thanks for the advice!!
Ed

[pinzwheeling]

Hi all:
Does anyone have experience with a 2.5 to 2.7 liter conversion in a 712M?

I'm considering the change, but would like to know what others have found with acceleration, top end speed, and especially driving up mountain highways (Cascades: elevation 0-4500ft). Would I notice a big difference between the two engines?
Any downside to the change besides the $?

Thanks for the advice!!
Ed

Huge difference. We have a 712M that we had Jim LaGuardia at Goatwerks build a 2.7 motor. Where a stock truck can do approx 42MPH up a grade by my office, the 2.7 equipped truck will do over 55MPH!

Not to mention that the 2.7 engine is much smoother; the piston build that Jim uses must smooth it out, as the 2.7 seems to be somewhat quieter also. Maybe it's my imagination?

Downside... none as far as I can see. Same gas mileage, huge difference in going up hills and a noticeable difference in acceleration.

[Thomas-E]

Hi

I've had the 2.7 for about 2 years now and am very pleased.

I was looking more at the increased compression than total cubic inches.

200 cc. is a small increase in size whereas a full point in compression is more of a factor in performance.

I also had the 712 transfer case swapped out for a 710 xfer case (I spend more time on highways). The acceleration and climbing capability are about the same, so I feel that 2.7 L. and 8.6 C/R really made up for the higher gearing.

I'm currently hauling around about 1000 lbs most of the time and I still feel that I have more than before. Mileage is down to 9-10 gpm, mostly because I am driving up and down some steep hills daily.

The kit will give you new piston rings and you might as well have a valve job done also (do you know how many miles are on your engine?)

If you don't go for the 2.7 kit I would recommend a compression check to see what condition the engine is in.

New rings and a valve job might just surprise you.

[lindenengineering]

Guys
I have done a number of these conversations which dictates a cam change to be successful. I have even had the up-sized unit in my own
Pinzgauer.

One manufacturer of the O/S piston (both made in the USA) has in my opinion a quality control issue and cylinder boring has to be done more accurately due to the fact that thinning of the cylinder wall to make it an oversize engine can distort the cylinder wall resulting in premature seizure. That together with an in service heat stress condition can result in seizure especially on cyls 3 & 4. So a higher level of machining/matching and assembly (torqueing) is required. The machinist I use, pre-loads the barrel on the boring jig by a home made tool to assimilate the clamping loads and distortion in that condition.
One thing that is paramount above all this is that the original spec 2.5 litre engine has off set pistons which is rudimentary to minimizing skirt thrust loads, power output and quietness of operation. The two brands of pistons made in the USA are NOT offset to the original Steyr specs.

In service I could'nt help noticing that there is a lack of tractability on the 2.7 litre unit at altitude (5500ft plus), so 1st gear has to be used to get it to to "go" and get some revs up on board, with swifter changes needed to keep it on the boil. Hence you had to pay attention to grades to keep the thing running but if you remember all this, then yes it does deliver "the goods" with more mid to up range power. At one stage I was contemplating a cam profile change for altitude but due to the low demand for such conversions I haven't bothered quite frankly and I sold my Pinz after I de-converted it and realized what a sweety it was in it original drive train form as I was driving it to the shippers.

Of course I have not experience of driving the unit at sea level where it may be a different animal but for Rocky Mountain conditions, give me the std unit which is a very flexible engine any time.
Dennis

[Erik712m]

I've driven in one 2.7L. nothing was stock. So I really can't compare it to mine. the factory did a 2.7L with cam, read through the old post. Herbert is still turning cams for it not regrinding the stock cam. Alan has posted in the past that he has exceeded 85 mph. Maybe we can get Alan to bring it up and drive it through Eisenhower Tunnel?


Jim, you ever had any recalls or failures on your 2.66/ 2.7 builds?


Gas milage does sound like a huge down side.

[lindenengineering]

Eric
Let me tell you Jim and I have discussed these failures at length and compared notes as two professionals in this industry. I will leave it up to him to divulge his experiences himself!

As to doing 85 MPH in a Pinzgauer! Frankly, that is not only dangerous to all other road users but highly irresponsible & childish. Lets hope he stays away from the Rocky Mountain area. The tunnel is @10600ft and hopefully we don't want Pinzaguers ending up as a nasty statistic and give the law makers more ammunition to get these fine collector trucks off the roads of Colorado.
By the way I have been privy to conversations where this has been mentioned.
Of course the WisDot experience will prove that this is a very real threat. We all need to beware
Dennis
ps I wouldnt drive my Landrover Discovery throught the tunnel at 85 mph and IT IS equipped/designed to handle speed. The safe speed is about 55 and no more than 65 mph down to Silverthorne. There are enough run away accidents in Colorado to mindlessly just add to them to statistics as the Colorado State Patrol who has to deal with all the carnage. Not nice having to pick up all the bits!
D

[audiocontr]

This topic is of interest to me

I currently have a 2.5, at sea level with 125# compression across the board. I'm also running the ZF (zd?) transmission

Are we saying that a 2.7 conversion (with Jim L cam) is not optimal? Would i be better sticking to the 2.5 in a rebuild and a valve job?

[lindenengineering]

This topic is of interest to me

I currently have a 2.5, at sea level with 125# compression across the board. I'm also running the ZF (zd?) transmission

Are we saying that a 2.7 conversion (with Jim L cam) is not optimal? Would i be better sticking to the 2.5 in a rebuild and a valve job?

From what you state the compression is low for some reason and a rectification is in order if you wish to spend money to remedy the situation. Jim's cam is fine at sea level as I stated for the engine and I have used it for use at 6500ft plus for a well know personality who has a dude ranch in the mountains and has two 710m's.
To re-iterate I was not entirely happy with the conversion on my own truck at 5500 ft plus simply because it lacked the "diesel" like tractability of the original 2,5 litre unit. At these altitudes the engine with the 2.7 litre convertion is less than desirable to me and the very fact that the pistons do not have an offset puts the piston technology (if you want to use that term( BACK more than 50 years!
That alone demerits in my opinion the conversion which should have the off set. That said, my customer was happy with what he got for the money and I suppose that is what is important. Whether these conversions will "last" in the long term is anyone's guess since the US pinzgauer crowd including yourself I daresay do so little mileage it is hard to determine a propensity of failure based upon experiences to date.
I can give the forum a potted history of the failures over the past 8 years or so which started with the RedBull unit number 2 and has lasted to just about every DIY unit that has come to my shop for rectification. Some have been de converted at the customers' behest others have had me do the conversion AGAIN with the same measure of success BUT I always point out the down side of the capacity increase as note in this forum discussion. I must point out that the level of assembly must be adhered to to enjoy any long term success.
Hope that helps you with your decision.
Cheers Dennis

[edzz]

Dennis you are indicating that 125psi on all cylinders is bad? In the past Scott has stated “120 across all 4 + or - 5% is not bad.” http://real4x4forums.com/PinzgauerBBS/v ... ompression what is proper for a fresh engine in stock trim? And what is accepted as being reasonable on an older engine?

Ed

[lindenengineering]

edz
Quote
]From what you state the compression is low for some reason

I didn't state it was bad-unquote


I would prefer to see 150 plus.
On a new one I have seen 175
There could be a number of reasons for the uniform low count including the need for a valve adjustment. (Or test equipment failings for that matter!)
Dennis,

[pinztrek]

As to doing 85 MPH in a Pinzgauer! Frankly, that is not only dangerous to all other road users but highly irresponsible & childish. Lets hope he stays away from the Rocky Mountain area.

Sorry, I have to challenge the blanket statements when it's made about a vehicle few have seen. (Erik drove it, however!)

I think we have to differentiate between stock pinz and Herbert's "pickle":
- 4 wheel dual caliper disk brakes
- G-wagon wheels
- Extra weight in the back plus no rear sides, so very low CG
- Tuned suspension to match above

Along with completely rebuilt steering gear, diff's, etc.

I can tell you that 85 mph in that pinz is more stable than any disco I've driven! Stopping distance is extremely good. About as good as you can get without ABS.

So 85 mph in it is not the hope and prayer that most early 70's vintage 4x4's are!

Given it's a fuel injected 2.7l, it has no problems getting there.

Nor with altitude changes. We've not taken it to 10k feet yet, but at 5000'ish from sealevel it's been fine. Since the system is barometrically compensated realtime, mixture will be fine no matter what. I suspect output will be lower without turbo/super charging, but it will run good.

We do hope to get it to Colorado soon, and play!. I'll let you know when we go through the tunnels. Been through them in a subie.

Have fun,

Alan

[lindenengineering]

Well if you say so ol' mate!
I sincerely hope with all those modifications & expense you took sometime to upgrade the frontal area of the rig in case of a collision. AND I don't mean a silly bull bar!
I have several examples of Pinz driving "heroics" in my shop. All I can say is that I am glad I wasn't in one of 'em when they hit something hard at a modest speed let alone 85 mph!
You should research a damming report by the German TuV on the Pinzgauer for a sobering assessment.
Noting the aghast/sick looks on Pinz owners faces when they see them!
Dennis

[Erik712m]

I imagine it would fare better than one of those Nancy pelosi rides or motorcycles people drive down the highway.

[pinztrek]

Well if you say so ol' mate!
I sincerely hope with all those modifications & expense you took sometime to upgrade the frontal area of the rig in case of a collision. AND I don't mean a silly bull bar!

Well, it's not my truck. And I understand the point about impact, but trying to hold 70's vintage 4wd's (or even most 70's vintage cars) to modern collision standards like the German test is at best an unfair comparison.

There are certain accidents I'd far rather be in a pinz than a CJ or a series of any year. For others, the pinz would be at a disadvantage. All will be worse than a camry.

Even getting into 80's & early 90's vehicles there were critical flaws in many mainstream vehicles. (certain exploding gas tanks in GM trucks come to mind)

Your overall point about speed is valid, but I believe it applies equally to pretty much all vintage 4wds in some form.

Likewise I don't commute in my pinz, nor drive it at 85 even for testing. I do keep it capable of freeway speeds and have driven some long trips in it. So Eisenhauer tunnel is safe for a bit!

Though they'd rather drive the pinz, my kids are in Mercedes beaters ('87 300d, etc) with airbags & crumple zones, as they will likely have a wreck, and will need a solid vehicle around them.

Have fun,

Alan

[lindenengineering]

Guys points taken.
Remember these trucks are Grey market and as such are not Fed approved (need I mention that??)

Fortunately to date the majority of owners of Pinzgauers have been mature older individuals that respect the truck for what it is. Consequently the vehicle tends to fly under the radar screen of State individuals who would rather not see it in the street or scudding along their favorite scenic byways.

Any adverse attention like speed related accidents and people getting injured/killed just reinforces the perceived fact that the owners are not responsible or they are unsafe. As one put it "Yahoos"!
As we know many of the mainstream insurance companies will refuse to indemnify a Steyr Pinzgauer on the Grey market category alone. You only need to surf the archives to find countless Pinz owners trying to find insurance for their rides. Need I say more???

The same goes for emissions-----Most get an E test, breath a sigh of relief and forget about it until the next registration period without any thought as to just how much pollutants are being bunged out into the atmosphere. Now I am not a fervent Greenie but there are lots out there that are! In Colorado the drive by E test are not just recording passes for 81 and newer vehicles they are recording ALL operations. It only takes a study and the strike of a pen to list the top ten polluters and you will get a letter in the mail revoking your registration you are not careful. Ask my mate Paul Underwood and his Wisdot experience & about what can really happen if you are complacent.
For info, I attended a seminar recently about advanced E controls and the Colorado vehicle parc. it is slated that ALL vehicles registered in the State have to comply to some new regs (IM240) by 2010.No matter where you live, the rural opt outs will be a thing of the past. If it has an internal combustion engine it must pass an e test.
The results will be a lot of crushed/scrapped vehicles just be hopeful that similar measures don't turn up in your State,. It is generally accepted in the US MV world quote;- What starts in California spreads to the rest of the country--So hold on to your hat!
Take care
Dennis