Search found 859 matches
- Wed Dec 24, 2014 5:04 am
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
What I can't understand is why he has cut the exhaust bottom so much lower than the transfer bottom. 5mm! You don't measure it, you can see it! Seriously, when I installed it I had no idea about any of this, but it's as plain as day now. In fairness I have the whole engine and can see the piston in ...
- Tue Dec 23, 2014 11:10 pm
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
Maybe it was that way to start with? Surely most tuning raises the roof of the port or widens it? I've learned a lot from this. As a four stroke chap none of this stuff has ever concerned me before and in a few days of thinking, measuring and reading I reckon I have a pretty good idea about a decen...
- Tue Dec 23, 2014 5:50 pm
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
bottom of the transfers should be lowered so they are level with the piston at bdc! sounds like who ever did this porting is pretty stupid tbh..... if the bottoms of the transfers had been as low as the bottom of the exhaust I would have said that maybe the tne was done for a very long stroke but a...
- Tue Dec 23, 2014 5:46 pm
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
I know of a longer than standard barrel that was intended to be run with a long stroke crank but went off for some porting first, only to find that the tuner simply applied the measurements that he had for tuning a standard length barrel... and in doing so completely f***** up a special barrel. :( ...
- Tue Dec 23, 2014 12:25 pm
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
Ok, kinda what I expected. Now check this. When the piston is at BDC, do the bottom of the transfers and the bottom of the exhaust port all line-up? If the bottom of the exhaust port lies lower than the bottom of the transfers, then this is not a good thing. Have a look and get back to the forum Th...
- Tue Dec 23, 2014 8:20 am
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
Aye, I'd rather just leave it at that for now. I don't want to spoil someone's reputation for one mistake.shocky wrote:A man who makes mistakes ....eden wrote:who ported the barrel?
If however he doesn't put it right then I will certainly have a change of heart.
- Mon Dec 22, 2014 11:05 am
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
Hmm. Ok, what about the distance from the bottom of the exhaust port to the top of the barrel? This should be a mil or so longer than the stroke. I suspect you are going to see a measurement that is 3mm longer than a 58mm stroke of the crank. Bottom of exhaust port to top of barrel is 62.6mm Edge o...
- Mon Dec 22, 2014 9:18 am
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
I suspect you're correct. I'll have a leisurely breakfast then measure. Also, I sent that photo to the chap who tuned it for me and he says he'll do me a new one after christmas. I don't know him personally as I'm new to this lambretta lark but his reputation is good so I've no reason to doubt him. ...
- Mon Dec 22, 2014 8:04 am
- Forum: Sports Bar
- Topic: The Song Title Thread - Pointless but Addictive!
- Replies: 25751
- Views: 4623198
Re: The Song Title Thread - Pointless but Addictive!
Since yesterday - strawberry switchblade
- Mon Dec 22, 2014 2:48 am
- Forum: Lambretta Tech
- Topic: exhaust port timings
- Replies: 60
- Views: 24761
Re: exhaust port timings
Sorry but that's doesn't really answer the question. Let me try again, what is the distance from the top of the barrel to the edge of the crown of the piston at TDC? Is the head recessed on that kit or does it have a gasket? About 1mm. Not recessed and I have 0.5mm gasket between head and barrel.