Merlin 102 and 130 similarities and differences

[BarnOwlLover]

I'm trying to figure out/get more details on the Merlin 102 and 130 series engines. Both were rated for the same performance specs in the Rolls-Royce Merlin PDF at World War II Aircraft Performance site, and both were given the development designation RM.14SM by Rolls-Royce. Of course, their applications were different (Merlin 102 it seems was used in the XP-51G Mustang and the 130 series were used in the DH Hornet) and for sure the 130 series had a downdraft supercharger intake, while the 102 kept the normal updraft intake. Were there any other notable similarities or differences between the engines? And was there other members of the 100 family that was similar to the 102?

 

[ThomasP]

This is what I have in my notes:

Merlin 100/101, test engines only, no production
Merlin 102, the first 100 series used for civil aviation, also used on some Australian Lincoln Mk 30A & 31
Merlin 104, as for Merlin 114 but different SC ratios
Merlin 113/114, used in the Mosquito PR Mk 34
Merlin 130/131, used in the Hornet/SeaHornet
Merlin 150, developed from Merlin 102 for civil aviation, redesignated Merlin 620

All 600 and 700 series were based on the Merlin 100. They received significant mods including new cylinder heads and cylinder banks to improve reliability issues, and various mods for better and more efficient running at cruise settings.

And reposted from the "Jumo 213 vs. Napier Sabre" thread:

Merlin 100/101/104/130/131____+20 lb max boost with 130 grade
_____________________________ +25 lb max boost with 150 grade

Merlin 113/114________________+18 lb max boost with 130 grade
_____________________________ +25 lb max boost with 150 grade

 

[Simon Thomas]

Lumsden notes the weight of the 102 as 1740 lb and the 130 as 1665 lb.

 

[BarnOwlLover]

This does lead me to ask which Merlin engine did approximate the 130's performance that had an updraft intake? Even if that means bringing up later Packard versions (though I'd like to know if a British version was capable of doing that)?

Or was the 130 series capable of being converted from downdraft to updraft intakes, like how some Merlin racing engines have been converted to using downdraft intakes?

 

[ThomasP]

Merlin 100/101/113/114 used updraft air intake arrangement.

 

[Simon Thomas]

From (IIRC) RRHT the Merlin in Perspective the Combat Years Alec Harvey-Bailey:
R.R. MERLIN ENGINES (Two Speed, Two Stage Supercharger, Intercooled).
MERLIN '100' SERIES.

R.R. and Air Ministry Nomenclature	Reduction Gear Ratio.	S/C Gear Ratio.	S/C Rotor Diam.	Dry Weight lb. +2+% Tol.	Combat Power Rating. H.P./R.P.M./Altitude Rated Boost.	Take-off H.P./R.P.M. and Boost lb./sq. in.	Max. Cruising and Max. Climbing Conditions. R.P.M. Boost.	General Description.
R.M.14.S.M. Merlin 100	.42	5.79 7.06	12.0" 10.1"	1680	1830/3000/5500' 1690/3000/18000' +25 lb./sq. in. (Grade 150 Fuel)	1640/3000 +18	Cruising M.S. 2650 +9 F.S. 2850 +9 Climbing 2850 +12	Merlin 100.-New series engine similar to Merlin 85 which it replaces. Features strengthened universal crankcase for end oil feed, strengthened cylinders with rocker cover breathers, stiffened valve springs, double packless gland oil lubricated ball bearing cool- ant pump, improved short intake elbow for mechanical accelerator pump and petrol injection features, overhung first-stage supercharger rotor, auxiliary gearbox drive, and electric starting. For Lancaster IV and Windsor.
Merlin 102 Merlin 102A	.42	5.79 7.06	12.0" 10.1"	1720	1780/3000/4500 1650/3000/16750' +20 lb./sq. in. (p)	1725/3000 +20	Cruising 2650+9 M.S. 2850+9 F.S. Climbing 2850+12	Merlin 102.-As Merlin 100 except that strengthened 60/80 H.P. auxiliary gearbox drive is fitted. Used on early Tudor I. Merlin 102A.-As Merlin 102 but with afterheater.
Merlin 130	.42 RH	5.79 7.06	12.0" 10.1"	1715	1980/3000/S.L. 1830/3000/13000' +25 lb./sq. in. (150 Grade Fuel)	1640/3000 +18	Cruising 2650+9 M.S. 2850+9 F.S. Climbing 2850+12	Merlin 130.-"Schneiderised" engines for De H. Hornet aircraft. As Merlin 100 (14 S.M. specification) but with strengthened "universal" crankcase with internal oil feed; down-draught intake and elbow; reversed coolant flow connections; no gearbox drive fitted. Right hand propeller rotation for Hornet port engine.