AN MAAS MAT’rElt
Sir, He t he article Bosman’s floliday ” in your June issue, I feel that the
figures given by Mr. Smith for his Alvis Speed Twenty are rather Optimistic. and 1 would point. out that at 1,000 r.p.m. in top gear the car would, with 4.5 to 1 axle ratio and 5.50 hr 19 tyres, give exaetly 19 m.p.h. Tin. Waring car with the sante ratios but 0.00 by 20 tyres would give 20.38 m.p.h. Per 1.000 r.p.m. Von quote 02 tn.p.b. at. 3,000 and 85 M.p.h. at 4,0410 r.p.m. ; I hat means the extra 1,000 r.p.m. gives an extra 23 m.p.h. ‘Vhereas al 4,000 r.p.m. the actual speed is 70
Now I don’t doubt that the car did 5,000 r.p.m. in third gear, but with Ilw type of box lilted to that model (all four synchromesh, separately mounted) the speed at 5,000 r.p.m, is about. 06 111.11.11. and not, as stated, over 70 m.p.h.
I litted iiii H.N.V. box to my own Alvis because of the higher indirect ratios on that type as opposed to the wider spaced ratios of tlw Alvis box and my car only does 72 m.p.h. in third at 5,000 r.p.m. with a Smitles correeted Speedo (wit) in 9 per cent.) and rev.-eounter (within 5 !)I’t. c(‘nt.) hot It checked agankl, each other.
My car. by the way, has a lapped head and block with no gasket., speeial valves tLi my design, and 7.00 by 18 tyres 11/1 the rear to cut down wheelspin. Also the pistons have heen liberally thrilled, and all moying ttarts polislted and balanced. and, of course, it has hardly :Any flywheel, the E.N.V. box being used as a elutelt. I am. Yours, etc_
Scholes. Non ix UOUTI.KOGE. I WC were not supplied by Mr. Stint Ii wit It the gear ratios I’m’ his car and nwy have based our caleolat ions on a gearbox different from Hutt in fact, is in the car. If so, the matter is regret tett mut we thank Mr. It out ledge for winding it (Mt. His figures correct the maximum speed we ;It tained to approximately 76 ni.tt.h..–ED.1 * * •