boost pressure
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=203672
Printed Date: 22 Nov 2024 at 7:42pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: boost pressure
Posted By: Larry O F
Subject: boost pressure
Date Posted: 15 Oct 2024 at 3:17pm
| Can anyone tell me what the boost pressure on a 1972 7GB track loader with an Allison 6-cylinder turbo charged engine should be? |
Replies:
Posted By: DrAllis
Date Posted: 15 Oct 2024 at 7:30pm
| It's not an ALLISON engine. It's an Allis-Chalmers engine. I assume it is a 3500 series engine ?? There's a metal tag on the left side of the engine block. I would expect a max turbocharger/intake manifold boost of 10 or 11 psi at full throttle under a good load. |
Posted By: HD6 Merv
Date Posted: 15 Oct 2024 at 10:47pm
Hi Dr Allis what would boost be for following 3, 11000 HD11 engines 1 HD11EP Bosch PSB fuel pump, TO6 turbo 2 HD11EP Roosa pump, TO4 turbo 3 HD11 series B; Robert Bosch inline pump, TO4 turbo. Full load is 'around' torque converter stall speed on these engines; all powershift models' Curious what boost would be for them Thanks Merv. ------------- tits tyres and tracks they all cost you money |
DrAllis wrote:Posted By: Larry O F
Date Posted: 16 Oct 2024 at 1:41pm
| You are correct it is an Allis Chalmers 3500 engine. I am only getting around 3 or 4 psi. I replaced the turbo several years ago with a substitute turbo and did not check the pressure until recently. I suspect the turbo I selected is not doing the job. |
Posted By: DrAllis
Date Posted: 16 Oct 2024 at 5:14pm
| Or you have a bad air leak somewhere in your piping or a blown intake manifold gasket. |
Posted By: DrAllis
Date Posted: 16 Oct 2024 at 5:15pm
| Cannot help you Merv. I have no info on those engines. |
Posted By: DMiller
Date Posted: 18 Oct 2024 at 4:49am
|
I can envision a Common thought here, Turbo changes to gain boost pressures, is not how it works. Fuel Delivery, Cylinder number and displacement, Max RPM to HP in a torque curve and finally the style of Turbine Blading in the Turbochargers. 90% of ALL turbos were constructed as Altitude Compensation Devices. IOW, there only to take thinning air at higher altitudes and increase the volume so engine could utilize all the fuel delivery rate for Lower Altitude Denser air. Many were on the older earlier engines to reduce Smoking by forced add of air to combustion as Smoke is nothing but Unburned Underutilized Fuel. Addition of a Charge Air Cooler to make that pressurized air even more dense was another development. Had real fun in the earlier Diesel Tractor Pull days, guys would buy a Cat Turbo knowing would add more boost for IH Allis or Deere engines, did NOT as much work out that way. Adding Compression, Adding Fuel and nearly any turbo could achieve same boost pressure just many were not designed for the turbine rotational speed these added measures put to them.
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Posted By: HD6 Merv
Date Posted: 18 Oct 2024 at 1:44pm
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Valid points there Dave; but in my case i only want the info pertaining to the 3 evolving series of powershift HD11s as a mate owns 2 of them, and me 1, though mine is currently deceased lol ! Not doing any hot rodding more curious to what they are. As havn,t seen that info in any AC books we have. The AC are different to the Cats that i 'do' know my way around esp D6C/D. in so far as torque converter stall speed in the 11s is very near to full load speed, 2000-2050 rpm and was interested in boost pressure for them as TCS speed is a known load given everything is ok with trans, and is often used as a 'field dyno' in evaluating engine or trans condition. Whereas in a D6, FL, and TCS are very different rpms and very different boost figures Thanks and cheers to anyone who can help, Mervyn. ------------- tits tyres and tracks they all cost you money |