Lycoming XR-7755 Contracts/Administrative, 1944

The Lycoming XR-7755
Contracts/Administrative Chronology, 1944
by Kimble D. McCutcheon

1 May 1944. Gen Arnold in Washington, DC telegraphed the Wright Field Resource Control Section (RCS), attention Lt Col G.H. Moriarty and Gen Gillespie . The telegraph referenced RCS Project 9 D Lycoming Division, The Aviation Corporation in the amount of $983,394.00. Representatives of the War Production Board Project Essentiality Division after a telcon with PPL engineers arrived at the following opinions:

It should not be necessary to acquire all of the additional production machinery listed to turn out one experimental engine and three 1-cylinder units in a year's time.
The 400 hp dynamometer test house costing $562,043.00 was not required since under the new plan there were no blade-and-fork connecting rods, hence no twin testing.
A portion of the gears could be subcontracted and many of the machine parts could be turned out on production machinery then located in Lycoming's production division.
It would take a year to manufacture the parts for one X-7 engine. Thereafter the engine was to be assembled and tested, which would take place during the second year. Additional tests to increase power would then be made for three years. At the end of five years the engine may be developed to the point of discussing production. Therefore, in effect, and engine development laboratory was being proposed without any prospect of a production model for six or seven years.

Gen Arnold requested that the RCS and PPL review the WPB opinions to insure agreement on the part of all MatCmd offices and submit recommendations to his office. The War Production Board (WPB) in Washington seemed favorably disposed toward the XR-7755 project, being fully cognizant of the need for engines of extremely high power. Gen Arnold further suggested that Lycoming and PPL engineers meet on this topic. On 2 May 1944, Lycoming's A.L. Johnson and Hugh Fenwick visited the PPL to "sell" PPL on going ahead with the contract and facilities. [Penciled notes by J.G. Blackwood. RG 342 RD2311 XR-7755, 1943-1948: 503-602 Conf and Tel Notes. 440501018-440501021.]

8 May 1944. The conference Gen Arnold had ordered was held at the Materiel Center and included representatives Col Gillespie, Chenoweth, Prescott and Blackwood from Wright Field; Hoffman, Heath, Ryder, Strassburg and Johnson from Lycoming; and Lt Col Moriarity, Chapman, and Lee Perkins from the WPB. and Wright Field on Lycoming facilities for development contract. The 2-cylinder testing was no longer required, but 3-cylinder radial and 4-cylinder block testing was required instead. The new dynamometers could be water cooled to give sufficient (450 hp) capacity; Lycoming's old dynamometers (150 – 200 hp) could handle some of the new test requirements. All usable dynamometer equipment from the XH-2470 and BX programs and their related 2- and 1-cylinder test engines were to be included with the new XR-7755 development.

Letter Contract No. W 33-038 ac-564 (11169) resulted from negotiations between Lycoming and MatCmd. This temporary contract covered development of the XR-7755 (Lycoming X-7), a 5,000 hp takeoff rated engine. Lycoming had indicated that certain facilities were required for this contract and had submitted a facilities request that was then being considered by the WPB. This conference was called to establish the necessity of certain items and determine that all parties involved were in common accord on the facilities requirements.

A misunderstanding regarding the new building was cleared up; the WPB had the impression that the new building was intended only for 2-cylinder testing, whereas the building was actually required for 1-, 3-, 4-, and 36-cylinder engine testing, as well as for testing engine components. Most of the machine tools Lycoming had requested were available and not of much value to other production programs. Lycoming stated that the large Bullard lathe would be needed in 60 days for machining the crankcase.

A common understanding of Lycoming requirements was reached and this led to an agreement to proceed with processing the requested facilities with two exceptions:
1) Machine tools not required and
2) 400 hp dynamometer not required as the old 250 hp dynamometer could be water cooled and capable of 450 hp.
The WPB was going to withdraw its objection to the Berol gear and spline grinder, along with the Bullard lathe. [Penciled notes by J.G. Blackwood. RG 342 RD2311 XR-7755, 1943-1948: 503-602 Conf and Tel Notes. 440508090-440508094.]

Lycoming had dynamometer capacity from 1,250 to 1,800 hp from previous XH-2470 program.

(Note: The teletype does not exist, so only the answers appear below)

Three parts sets were scheduled for machining during the first and second contract phases, which covered about one year, but with overlap between the phases.
The 1-, 3- and 4-cylinder units were still required and would replace the old single and twin test engines that used blade-and-fork connecting rods.
It was recognized from the start that subcontracting was possible, but Lycoming claimed unsatisfactory subcontracting experience due to delivery delays and part quality. There was no knowledge of what production machinery was available at Lycoming.
The schedule was not as disciplined as presented. Testing was to be accomplished as stated but in the meantime parts for the 2nd engine, spares and replacement of broken or redesigned parts would also be a factor. If a three-year development schedule was accurate after a year, a total time of 4 – 5 years might be possible instead of 6 – 7.

[Penciled notes by J.G. Blackwood. RG 342 RD2311 XR-7755, 1943-1948: 503-602 Conf and Tel Notes. 430717029-430717031.]

12 Aug 1944, Contract W-33-038 ac-564 (11169) with the Aviation Corporation, Lycoming Division, Williamsport, Pennsylvania. Approved 18 August 1944 by Brig Gen K.B. Wolfe, Commander, Materiel Command.
AFP 381731, 401826
Classification: 02-A
Cost Plus Fixed Fee Supply Contract with The Aviation Corporation, Lycoming Division (the Contractor)
Estimated Cost: $3,651,575.00; Fixed Fee: $80,000.
Debit ACA 1942-44, 2-4005 P 611-09 A 212/40705 = $1,571,575.00 (1944 funds).
ACA 1942-45, 502-5150 P 611-07 A 212/50705 = $2,080,000.00 (1945 funds).
Program: MX-434

This formal contract supersedes letter contract dated 24 Aug 1943, as amended. (Note: The author has streamlined the contractual "boilerplate" wording.)

(a) The Contractor shall, within the time specified in Article 4 hereof, perform, manufacture, furnish and deliver to the Government the following services, materials and articles:

Item 1. Design, build and test cylinders of a design that may form a component of the Lycoming Engine AAF designation XR-7755-1, Lycoming Specification No. 2020 dated 16 Jun 1944, with such modifications thereto as Contractor and the PPL may agree upon. Design and build 4 single-cylinder test engines and required spare parts to accomplish single-cylinder testing. Perform the following tests with such single-cylinder test engines and such test cylinders:

(a) Necessary tests shall be run to determine the maximum compression ratio that can be used to develop a takeoff power rating of 231 indicated mean effective pressure (imep) at 2,600 rpm with a specific fuel consumption (sfc) not exceeding 0.59 lb/indicated horsepower (ihp)/hr. These tests shall be conducted with at least three compression ratios of approximately 7.5:1, 8.5:1 and 9.5:1. These tests shall be run with various valve and spark timings in order to determine the optimum valve timings and spark advance to produce maximum power output in the cylinder.
(b) Necessary calibration tests shall be conducted using the maximum usable compression ratio found in paragraph (a) above to determine the optimum valve timing and spark timing at cruising conditions of 1,600 rpm and 141 imep to give maximum fuel economy that shall be not greater than 0.34 lb/ihp/hr.
(c) Necessary tests shall be run at cruising conditions using the optimum valve and spark timing found in paragraph (b) above to accomplish the following performances:
- (1) 1,300 rpm, 89 imep, 0.336 lb/ihp/hr.
- (2) 2,200 rpm, 155 imep, 0.360 lb/ihp/hr.
Results in triplicate shall be furnished covering the foregoing tests.

Item 2. Design and necessary test work the parts required for single-cylinder performance investigations with previously-designed liquid-cooled cylinders of different sizes (5.250" x 4.750" (the size of the Lycoming O-1230 and H-2470 cylinder), 5.750" x 5.375", 6.125" x 5.375") than were to be used on the XR-7755. The purpose of these investigations shall be to develop design criteria on compression ratio, valve timing, spark timing, exhaust back pressures, various fuels, cylinder pressure at 8.5:1 compression ratio; to develop special techniques and methods for use in determining performance characteristics, and similar items all of which shall relate to the ultimate development of said XR-7755-1 engine, as approved by the PPL. Reports in triplicate covering performance investigations accomplished shall be furnished.

Item 3. Design and necessary test work and parts required for single-cylinder endurance tests during the period ending 1 Sep 1944 on cylinders of the same general design but different sizes than the XR-7755-1 engine (known as BX, 5.750" x 5.250", and short-stroke X-7, 6.375" x 5.375"). These tests shall be directed to the ultimate development of said XR-7755-1 engine and shall not exceed 600 hours of operation; at least 60 hrs of which shall be at takeoff power and speed, 60 hrs at normal power and speed; the remainder to be at or above minimum cruising conditions. Reports in triplicate shall be furnished on the foregoing tests.

Item 4. Engineering studies, design, layout, and detail work covering preliminary design of the said XR-7755-1 engine, meeting the requirements of said Lycoming Specification No. 2020, such design being subject to approval and release by the Commanding General, AAF Materiel Command, Wright Field, or his duly authorized representative. Design reports and blueprints of assembly and detail drawings in triplicate pf the power section of the engine shall be furnished.

Item 5. Design and fabricate a complete mockup of said XR-7755-1 engine described in said Lycoming Specification No. 2020.

Item 6. Rough, semi-finished and finished parts for said XR-7755 engine as released by progress of engineering work specified under Item 4, but in quantities not to exceed those required for 3 engines and the test program called for in this contract.

Item 7. Three sets of rough forgings, castings, and bearings, as required, to make available for fabrication material for 3 complete sets of parts for said XR-7755-1 engine.

Item 10. Provide 3 fuel injection pumps, 12-cylinder, complete with 36 nozzles. This equipment shall be designed for said XR-7755-1 engine.

Item 11. Provide 1 set of fuel injection equipment, complete, suitable for installation on said XR-7755-1 engine.

Item 12. Miscellaneous Work

(a) The Contractor shall from time to time be directed in writing by the Contracting Officer, to manufacture, furnish and deliver to the Government miscellaneous materials and shall furnish services in the amount of not to exceed the estimated cost for this Item shown in Article 2 hereof. The exact kind and quantity of articles, materials and services so to be furnished shall be determined by the Contracting Officer and may include, but shall not be restricted to, designing, building, testing and other work in connection with the development and perfection of said XR-7755-1 engine and other work, articles or things relating to aircraft engines that the Contractor is able to perform and supply.
(b) The Contracting Officer shall from time to time issue written requests to the Contractor for articles or services called for hereunder. Each request shall state that it is issued under Item 12 of Contract W 33-038 ac-564 and shall set forth the particular articles or services to be furnished, quantities of such articles or nature of such services and the time of performance desired.
(c) The Contractor shall proceed at once to prepare and submit to the Contracting Officer a list of the articles or services called for prepared as follows:
- (1) Three copies of each list shall be prepared on paper approximately 8" x 11" one of such copies being carbon-backed on vellum or other paper in form suitable for reproduction by blueprinting or other standard method.
- (2) Each list shall show the date and origin of the applicable request, shall be numbered in sequence according to the date of issuance thereof commencing with the numeral "1" and shall bear at the top of the first page and at the foot or each succeeding page such number of the list and the designation of this item, for example, "Exhibit 1 to Item No. 12 of Contract No. W 33-038 ac-564".
- (3) Each list shall show as to each item listed therein the item number, drawing or part number, if any, description of article or work, quantity called for, estimated unit cost, estimated special packing charges, if any, and the total estimated cost of all items listed and the fixed fee applicable thereto, the proposed delivery date or performance, destination and manner of shipment.
- (4) The three copies of the list shall be signed at the end thereof each as an original by an officer or other person authorized to bind the Contractor and shall have the corporate seal affixed. Provision will also be made at the end of each such list for the written approval of the Contracting Officer. Three copies of the list after signature by the Contractor as indicated above shall be forwarded to the Contracting Officer. Each such list shall be subject to the approval of the Contracting Officer and when so approved and with such changes therein as may be agreed upon by the Contractor and the Contracting Officer such approved list shall be attached to and become a part of this contract and be published as a numbered exhibit hereto. Any disputes regarding such list shall be determined in the manner provided in Article 16 (Disputes) hereof. One of the three copies of the list approved by the Contracting Officer will be returned to the Contractor.
(d) Upon the initial forwarding of the Contracting Officer of the list prepared to show the estimated cost of the items requested, the Contractor shall proceed forthwith to furnish the articles and services covered thereby.
(e) Calls hereunder may be made by the Government during the period commencing upon the date of this contract's approval and expiring at midnight on 30 Jun 1948 provided that the making of any calls hereunder after 30 Jun 1945 shall be contingent upon the availability of funds appropriated therefore.

(b) The Contractor during the performance of this contract shall submit the following reports to the PPL, Engineering Division, Materiel Command:

(1) A biweekly report listing all the parts replaced during the test programs called for hereunder, segregated into the following groupings:
- (a) Broken parts due to failure
- (b) Obsolete parts, change in design
- (c) Defective castings, porosity and cracks
- (d) Worn parts
- (e) Defectively machined parts
- (f) Defective forgings
- (g) Metallurgical rejections
- As to each part such list shall show the part number, nomenclature, number of units replaced and the unit cost of the replacement part.
(2) On the 15th of each month a detailed analysis of the costs incurred by the Contractor for work performed during the preceding calendar month and a summary of the work performed during such month on each item of work listed in Article 1(a) hereof, or in Exhibits under Item 12 thereof.

(c) Tests called for by this contract shall be witnessed by the Government Representative. The Contractor shall give the Government notice a reasonable time in advance of the running of each test so that such representative will be present at the time of the test.

(d) It is understood that the Contractor has been working for a long period of time on the project of developing and engine such as said type XR-7755, and that the Government authorized the Contractor to do such work at the expense of the Government in anticipation of this contract, beginning 28 Jul 1943. It is further understood that said developmental project was until recently designated as the Lycoming X-6 Engine Project. It is agreed that all the terms of this contract shall apply to work of the Contractor done in anticipation of this contract from and after 28 Jul 1943. It is further agreed that that work done subsequent to 28 Jul 1943 by the Contractor in the development of the Lycoming X-6 engine in accordance with the Contractor's Specification No 2020 dated 5 Jul 1943 shall, to the extent that such work is within the scope of the work called for by Items 1 – 11, inclusive of Paragraph (a) of this Article, be considered work done under this contract.

Article 2 – Estimated Costs (Based upon data on file in the office of the Commanding General, Army Air Forces.

Item	Estimated Cost
1	$213,500.00
2	$56,000.00
3	$40,000.00
4	$260,000.00
5	$40,000.00
6	$298,000.00
7	$75,000.00
8	$359,500.00
9	$150,000.00
10	$18,825.00
11	$30,270.00
12	$2,000,000.00

(b) For purposes of determining the amounts payable to the Contractor under this contract, allowable items of cost will be determined by the Contracting Officer in accordance with regulations for the determination of the cost of performing a contract as promulgated by the Treasury Department in Section 26.9 of Chapter I of Title 26 of the Code of Federal Regulations, as contained in T.D. 5000 and approved by the Secretary of War, 2 Aug 1940, it being understood and agreed, without limiting the generality of the foregoing that:

(1) It is recognized that Contractor has been doing work called for by this contract under a Letter Contract dated 24 Aug 1943, that, as recited in said Letter Contract, the Government and the Contractor contemplated that said Letter Contract would be superseded by a fixed-price contract, that, the Government determined that because of the nature of the work involved the formal contract between the parties should be a Cost-Plus-A-Fixed-Fee type of contract, that the Contractor at the request of the Government agreed to enter into this contract on a Cost-Plus-A-Fixed-Fee basis, that as a result of wording under the belief that the Letter Contract would be superseded by a fixed-price contract, the Contractor prior to 1 Aug 1944 maintained records of its expenditures in accordance with its regular methods of conducting business under fixed-price contracts and in addition, entered into certain orders for parts and tooling on an "advise-price" basis. Contractor agrees that it will use its best efforts to convert said "advise-price" orders to a fixed-price or time-and-material basis within a reasonable time after the execution of this contract. All costs (including costs under such "advise-price" orders) that have been incurred by the Contractor pursuant to said Letter Contract and that are found by the Contracting Officer to have been reasonably incurred in the light of the circumstances stated in this subparagraph, shall be allowable items of cost hereunder to the extent that such costs are of the types that would have been allowable hereunder, if incurred after the approval of this contract.
(2) Interest on unreimbursed portions of the actual investments in a facility or facilities used for the performance of this contract and acquired pursuant to any Emergency Plant Facilities Contract or Contracts with the Government, now in effect of hereafter entered into, including any amendment thereof, at the rate or rates provided for in the Emergency Plant Facilities Contract or Contracts involved, shall be an allowable cost hereunder to the extend that such interest accrues during the performance of this contract; provided, that if the facility or facilities also are used concurrently for the performance of another contract or contracts, only so much of such interest as is proportionate to the use of the facility or facilities for the performance of this contract shall be an allowable cost hereunder; and, provided further, that such interest shall not be an allowable cost hereunder to the extent that such interest is aloe as a cost under any other contract or contracts.
(3) Cost of such bonds and insurance as the Contracting Officer may approve or require and cost and expenses incurred in the defense and/or discharge of such claims of others on account of death or bodily injury of persons or loss or destruction of or damage to property as may arise out of or in connection with the performance of the work under this contract shall be an allowable item of cost hereunder, provided that such reimbursement shall not include any amount for which the Contractor is indemnified or compensated by insurance or otherwise, or any amount for which it would have been so indemnified or compensated except for the failure of the Contractor to procure or maintain bonds or insurance in accordance with the requirements of the Contracting Officer. The foregoing shall not restrict the right of the Contractor to be reimbursed for the cost of reasonable insurance covering the Contractor's property or property for which the Contractor is responsible to someone other than the Government and which is used or to be used in the performance of this contract.

(c) In the event that prior to final settlement under this contract, the above mentioned Regulations (T.D. 5000) shall have been amended either before or after the effective date of this contract, so as to provide for additional allowable items of cost, such additional items shall be considered allowable items hereunder.

(d) Any cost incurred by the Contractor under the terms of this contract that would constitute an allowable item of cost under the provisions of Paragraph (b) of this Article shall be included in determining the amount payable under this contract, notwithstanding any provisions contained in the specifications or other documents, incorporated in this contract by reference, designating services to be performed or materials to be furnished by the Contractor and its expense or without cost to the Government.

(e) The cost-plus-a-percentage-of-cost system of contracting shall not be used by the Contractor in procuring articles, materials, supplies or services required for the performance of this contract.

(f) The Contractor shall, to the extent of its ability, procure materials and services at the most advantageous prices available, with due regard to securing prompt delivery of satisfactory materials, take all cash and trade discounts, rebates, allowances, credits, salvage, commissions and bonifications, and when unable to take advantage of such benefits it shall promptly notify the Contracting Officer to that effect and the reason therefore. In determining the actual net cost of articles and materials of every kind required for the purpose of this contract, there shall be documented from the gross cost thereof all cash and trade discounts, rebates, allowances, credits, salvage, commissions and bonifications that have accrued to the benefit of the Contractor or would have accrued except for the fault or neglect of the Contractor. Such benefits lost through no fault or neglect on the part of the Contractor, or lost through fault of the Government, shall not be deducted from gross costs.

(g) In fixing the amount of the fee called for under the terms of paragraph (a) of this Article, the parties have understood and agreed that, in view of the necessity for increasing war production through subcontracting and in order effectively to carry out this contract, the Contractor will enter into subcontracts for the performance by subcontractors of parts of the work to be performed in connection with the supplies or services to be furnished hereunder. Subject to the providions of paragraph (f) of this Article and to the provisions of Article 27 hereof, any amounts poaid to subcontractors under such subcontracts, including any fees or profits to subcontractors for which such subcontracts may provide, shall constitute allowable items of cost to the Contractor and the Contractor shall be reimbursed for such costs as provided in Article 6 hereof without any reduction by reason thereof in the amount the Contractor's fee called for under the terms of said paragraph (a).

(a) Work and material called for by the items of Article 1(a) hereof will be completed and delivered in accordance with the following schedule:

Item	Delivery Schedule
1(a)	≤ 4 months after contract approval
1(b)	≤ 5 months after contract approval
1(c)	≤ 6 months after contract approval
2	By 1 Oct 1944
3	≤ 30 days after contract approval
4	≤ 8 months after contract approval
5	≤ 2 months after contract approval
6	≤ 8 months after contract approval
7	≤ 8 months after contract approval
8	Each test as soon as possible after XR-7755-1 development permitted such test to be run. Each test report was to be delivered within 30 days after test completion.
9	≤ 12 months after contract approval
10	≤ 3 months after contract approval
11	≤ 12 months after contract approval
12	As specified in the Exhibits to be attached hereto pursuant to Item 12 of Article 1(a) hereof.

Article 4(b) through Article 46 are generic contractual boilerplate defining how business was to be done with the Government. [RG 342 RD 2311 XR-7755 Contract W-33-038AC-564. 1st Contract. 002-045.]

18 Oct 1944. Blackwood released ten calls to Contract W-33-038 ac-564, all dated 30 Aug 1944. Call 1,Exhibit 1 consisting of 10 Call Items to Contract Item 12, was approved on 13 Nov 1944 by Air Corps Contracting Officer 1st Lt Robert B. Thomas.

Call 1 Item 12-1. Necessary design and test work and parts required for 50 hr single-cylinder endurance test of Lycoming XR-7755-1 cylinder at alternating 30 min periods as follows:

In this test the optimum valve timing and spark advance for takeoff, as found in Item 1(a) of this contract, shall be used for the takeoff period. The optimum valve timing and spark advance for intermediate cruise, as found in Item 1(b) of this contract shall be used for all cruising periods. Three test report copies shall be furnished. Delivery = 1 May 1945; estimated cost = $15,431.00.

Duration (min)	Rating	rpm	imep (psi)	isfc (lb/hp/hr)
30	Takeoff	2,600	231	0.59
30	Cruise	2,200	155	0.39
30	Takeoff	2,600	231	0.59
30	Cruise	1,600	141	0.333

Call 1 Item 12-2. Necessary design and test work and parts required for 2,000 hours of single-cylinder endurance tests of Lycoming XR-7755-1 cylinder. This item shall cover tests of revised and/or improved designs. At least 200 hrs shall be at or above takeoff power and speed; 200 hrs at or above normal power and speed; the remainder at or above minimum cruising. All ratings shall be as defined in Item 5 below. A maximum of 25% of this time may be accomplished with a short-stroke XR-7755-1 cylinder. Three report copies shall be furnished. Delivery = 1 Sep 1945; estimated cost = $154,326.00.

Call 1 Item 12-3. Necessary design and test work and parts required for 500 hrs of single-cylinder performance investigations with previously designed liquid-cooled cylinders of a different size (5.250" x 4.75"), that that to be used on the Lycoming XR-7755-1. The purposes of these investigations shall be to develop design, criteria on compression ratio, valve timing, spark timing, exhaust back pressures, various fuels and special techniques and methods for use in determining performance characteristics and to determine cylinder pressure at 8.5:1 compression ratio. These investigations shall also cover similar items of work relating to the ultimate development of the Lycoming XR-7755-1 engine, as approved by the PPL. At least 50 hrs shall be at or above takeoff imep and speed and 50 hrs at or above normal imep and speed, the remainder to be at or above minimum cruising conditions; all ratings shall be as defined in Item 5 below. Three report copies shall be furnished. Delivery = 1 Sep 1945; estimated cost = $23,133.00.

Call 1 Item 12-4. Necessary design and test work and parts required for 1,000 hrs of XR-7755-1 single-cylinder performance and calibration testing of the original, revised and/or improved designs. At least 100 hrs at or above normal power and speed; the remainder at or above minimum cruising; all ratings shall be as defined in Item 5 below. The tests shall include the following:

(1) Effect of exhaust pressure on performance.
(2) Investigation of engine performance with Reference Fuel 28R and Specification AN-F-33 fuel.
(3) Engine performance and low-tension ignition.
(4) Cooling investigation
(5) Comparison of various methods and locations of fuel injection.
(6) Effect of intake air temperature on engine performance.
(7) Spark plug investigation.
(8) Piston and ring development.
(9) Complete sea-level performance calibration.
(10 Vibration investigation of test set-ups.
(11) Develop special test techniques and methods to be used to determine performance characteristics of the XR-7755-1 single-cylinder engine.
(12) Investigation of cylinder pressures and studies of indicator cards.
(13) Such other tests as are approved by the PPL, Engineering Division, AAF MatCmd, WF, Dayton, Ohio.

Three report copies shall be furnished. Delivery = 1 Sep 1945; estimated cost = $77,162.00.

Call 1 Item 12-5. Necessary design and test work and parts required for 150 hr single-cylinder endurance test of a Lycoming XR-7755-1 cylinder in accordance with the schedule given in paragraph F-3d of Specification No. AN-95-2b, dated 11 Aug 1942, based on a normal multi-cylinder engine rating of 4,000 hp at 2,300 rpm and 205 imep, and a takeoff rating of 5,000 hp at 2,600 rpm and 231 imep, with the following exceptions:

(a) In paragraph F-3d(5) of Specification No. AN-9502b, "high cruising" conditions as defined at the end of this item shall be used in lieu of 70% normal rated power and 89% normal rated speed.
(b) In paragraph F-3d(6) of Specification No. AN-9502b, "cruising conditions" as defined at the end of this item shall be used in lieu of 60% normal rated power and 84% normal rated speed.
(c) In paragraph F-3d(7) of Specification No. AN-9502b, "low cruising" conditions as defined at the end of this item shall be used in lieu of 42% normal rated power and 56% normal rated speed.
(d) If he so desires, the Contractor may proportionally reduce the length of time of the periods in Specification AN-9502b, to permit running several shortened complete test sequences of all powers and speeds, but the total amount of running shall be 150 hrs at conditions stated in Specification AN-9502b, as amended by this item.
In this test the engine shall be fitted with a shiftable camshaft having two sets of cams to give the optimum takeoff and cruising valve timing determined in the calibration tests of Item 1 of this contract. A variable timing magneto drive shall also be used in this test to give optimum takeoff spark advance and optimum cruising spark advance as determined in said Item 1. The performance requirements of the Lycoming XR-7755-1 multi-cylinder engine and of the corresponding single-cylinder test engine shall be as follows, for the purpose of this test:

				Multi- Cylinder			Single- Cylinder
Rating	bhp	rpm	bmep (psi)	bsfc (lb/hp/hr)	Mechical Efficiency	imep (psi)	isfc (lb/hp/hr)
Takeoff	5,000	2,600	196	0.70	0.85	231	0.595
Military	5,000	2,600	196	0.69	0.85	231	0.595
Normal	4,000	2,300	178	0.60	0.87	205	0.522
High Cruising	3,000	2,200	139	0.40	0.90	155	0.360
Crui 1sing	2,000	1,600	128	0.37	0.90	141	0.333
Low Cruising	1,000	1,300	102	0.39	0.88	89	0.336

Three report copies shall be furnished. Delivery = 1 Sep 1945; estimated cost = 23,146.00.

Call 1 Item 12-6. Design, layout and detail work covering design of the said Lycoming XR-7755-1 engine, meeting the requirements of Lycoming Specification No. 2020 dated 16 Jun 1944 with such modifications thereto as Contractor and PPL may agree upon. Design reports and blueprints of assembly and detail drawings in triplicate of all except the power section of the engine shall be furnished. Delivery = 1 Mar 1945; estimated cost = $158,582.00.

Call 1 Item 12-7. Design studies in triplicate of the single-speed, two-speed and dual-rotation model reduction ears suitable for the Lycoming XR-7755-1 engine. Prints and design data in triplicate of the detailed design of one of the said propeller reduction gear as selected by the PPL. Delivery = 1 May 1945; estimated cost = $94,761.00.

Call 1 Item 12-8. Completion of rough, semi-finished and finished parts to complete work initiated and partially completed in Item 6 of the contract. Deliveries = 1 May 1945, 1 Jul 1945 and 1 Sep 1945; estimated cost = $854,276.00.

Call 1 Item 12-9. One finished XR-7755-1 parts set for spares. Delivery = 1 Sep 1945; estimated cost = $208,135.00.

Call 1 Item 12-10. Necessary parts to complete two reduction gear units in accordance with the detailed design of the type selected by the Government in Call Item 12-7. Delivery = 1 Mar 1946; estimated cost = $139,819.00.

[RG 342 RD2311. XR-7755\XR-7755 Contract W-33-038AC-564, Contract Calls. 001-013.]

02 Dec 1944. Change Order No. 2. Contract W 33-038 ac-564, Article 1, Paragraph (b), Subparagraph (1), as amended, is hereby changed to read as follows:

"(1) A bi-weekly report covering a brief summary of work accomplished on all items of the contract. Such report shall also include a list of all parts replaced during the test program called for hereunder, segregated into the following groupings:

(a) Broken parts due to failure
(b) Obsolete parts, change in design
(c) Defective casting, porosity and cracks
(d) Worn parts
(e) Defectively machined parts
(f) Defective forgings
(g) Metallurgical rejections

As to each part such list shall show the part numbers, nomenclature, number replaced and unit cost of the replacement work.

If, however, the Contractor, due to delay in compiling the list of parts called for above, cannot submit the bi-weekly report with said list attached then the Contractor shall submit sais report on engineering work accomplished as called for and submit the list of parts separately at the earliest possible date thereafter."

2. Except as provided in this Change Order, no adjustment of the estimated cost or fixed price shall be made for or on account of any changes effected hereby.

[RG342 RD2311 XR-7755 Contract W-33-038AC-564 Supp Agreements, CCNs, COs. 441202013-441202014.]

29 Dec 1944. J.G. Blackwood informed Lycoming on behalf of Col Donald J. Keirn, Acting Chief, PPL, Propulsion and Accessories Subdivision, Engineering Division, that Contract W 33-038 ac-564 was to be changed to clearly cover three- and four-cylinder test engines. While these were discussed during contract negotiations and were covered in the original cost estimates, the Government thought clarification was in order in the form of Contract Change Notification Serial No. N-26155.

[RG 342 RD 2311 XR-7755 Contract W-33-038AC-564 Authorizing Correspondence. 003.]

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Maximum Present Rating	5,000 hp
Possible Future Rating	7,200 hp
1-cylinder testing:	hp = 5,000 / 36 = 140 hp
	hp = 7,200 / 36 = 200 hp
3-cylinder testing	hp = 5,000 / 12 = 417 hp
	hp = 7,200 / 12 = 600 hp
4-cylinder testing	hp = 5.000 / 9 = 555 hp
	hp = 7,200 / 9 = 800 hp
9-cylinder testing	hp = 5,000 / 4 = 1,250 hp
	hp = 7,200 / 4 = 1,800 hp