Search found 519 matches

by Rich_T
Mon Apr 30, 2018 7:17 am
Forum: Lambretta Tech
Topic: Looking for engine case engineering drawings
Replies: 7
Views: 1151

Re: Looking for engine case engineering drawings

To find the centre line of the hub bearing you first need the the centre line for the case. The case centre line is between the rear side case dowel and the forward-most exhaust stud. Clocking off the centre of the gearbox lay shaft bearing, the rear axle centre line is 69.31mm aft. Hope that helps
by Rich_T
Sun Mar 04, 2018 7:22 pm
Forum: Lambretta Tech
Topic: 60x115 Crank Kit Options
Replies: 1
Views: 697

Re: 60x115 Crank Kit Options

You can run a GT186 on a 60x115 rod. You'll need 8mm packing but the cylinder is 3mm shorter than stock so it will all fit under the cowlings, worst case is to make a 5mm packer between between head cowling mag flange.
by Rich_T
Fri Feb 23, 2018 10:25 pm
Forum: Lambretta Tech
Topic: GT big block experiance : New GT crank info added
Replies: 516
Views: 118117

Re: GT big block experiance : New GT crank info added

has soon come, yet ? Soon has arrived! Side cases available from Wednesday next week. There is a bunch on back order some please register your interest quickly. The price is £160 inc VAT for machined side case and kick start bushes fitted. The target was less, I know, but the tooling was a very tou...
by Rich_T
Fri Jan 12, 2018 10:23 pm
Forum: Lambretta Tech
Topic: GT big block experiance : New GT crank info added
Replies: 516
Views: 118117

Re: GT big block experiance : New GT crank info added

czeckson wrote:
Mon Jan 08, 2018 8:04 pm
we need the side casing
It is very close, I'll be posting pictures soon
by Rich_T
Sun Dec 10, 2017 5:37 pm
Forum: Lambretta Tech
Topic: Cubes, cubes, I want more cubes!!!
Replies: 51
Views: 5874

Re: Cubes, cubes, I want more cubes!!!

The BMEP thing is really useful for comparison of engines of a similar type where rules apply. If there is some form of parity in principle for example 2T, no forced induction, pump gas (standard fuel, no funky additives) and general restriction on port layouts (for example, gasket layout & studs )....
by Rich_T
Sun Dec 10, 2017 5:23 pm
Forum: Lambretta Tech
Topic: Cubes, cubes, I want more cubes!!!
Replies: 51
Views: 5874

Re: Cubes, cubes, I want more cubes!!!

BMEP for a 4T is double that of a 2T engine. Many 4T engines are a forced induction which helps the fuel loading, you get volumetric efficiencies much higher than 100% (typical 2T is about 80-85%-but it varies on where you are in the rev range because of the expansion pipe) . Also the bore stroke ra...
by Rich_T
Sun Dec 10, 2017 1:17 pm
Forum: Lambretta Tech
Topic: Cubes, cubes, I want more cubes!!!
Replies: 51
Views: 5874

Re: Cubes, cubes, I want more cubes!!!

One thing on the 14BMEP engine. It is not known what fuel it was running. The power delivered by engine is directly proportional to how much fuel it burns in the cylinder. Fuel won't burn with out oxygen so the quick and dirty process to get more oxygen without using atmospheric gas (approx 20%) is ...
by Rich_T
Sun Dec 10, 2017 1:06 pm
Forum: Lambretta Tech
Topic: Cubes, cubes, I want more cubes!!!
Replies: 51
Views: 5874

Re: Cubes, cubes, I want more cubes!!!

Hi Holty, A pal of mine had one of these AF barrels too so I totally understand what you mean. However, that was based on a standard iron whereas some of the castings for kits could well have thicker cores so allow for more than the iron barrels. Cheers Adam Be careful on the assumption that boring...
by Rich_T
Sun Jul 09, 2017 4:22 pm
Forum: Lambretta Tech
Topic: SS240
Replies: 24
Views: 4657

Re: SS240

Nope, not without major surgery to the piston. The modified TS250er piston is shortened by 5mm and has windows machined in it. The compression height from centre of pin to top edge of piston is 34mm. You could ask MB if they have a conversion piston of some sort or you could make some top hat bushes...
by Rich_T
Fri Jul 07, 2017 7:16 pm
Forum: Lambretta Tech
Topic: SS240
Replies: 24
Views: 4657

Re: SS240

Interesting, this might highlight a compatibility issue with Casa cranks and cases. The GT240's use an 18mm wrist pin in the piston. Please check that the Casa conrod has a 22mm diametre small end. If not you'll be restricted to kits with 16mm pins or replace the casa rod with a GT rod if they are d...