486 replies to this topic

[miniman92]

What did it fail on?

[PhilipGCaldwell]

1)rear nearside brake drum is binding badly, I was aware of it (it is getting the wheel hot during a run out, I could hear it rubbing/catching) so needs easing off.

2)handbrake insufficient aswell (which I was aware of but thought it might 'scrape' through MOT)

nothing major, I'm looking after my Dad's house this weekend so I will have the luxury of a garage to fix it in

Edited by PhilipGCaldwell, 13 January 2012 - 08:28 PM.

[Sam Walters]

Hours work then. Jobs a goodun!

[PhilipGCaldwell]

Hours work then. Jobs a goodun!

aye, nothing to bad, I always fear MOT time as a mini owner!

[twrminisport]

GOod good :) Only a parital retest need then :)

Jesus

[Sam Walters]

I need to get my flow bench running before I can do some proper figures. Ive made some presumptions here in my calculations.

A full on miglia head flows 130cfm @ 28 inches drop. a Standard head flows 90cfm. With a bit of reading in tuning the a-series engine by david visard. Ive come up with a figure for a good home modified head. 110cfm inlet. 90cfm exaust. Both at 400thou. Using a linear scale to 0 i used these as my air flow data points. Obviously not accurate.

Calculating with the 649 on a 1330 bought back a figure of 115hp at 7500rpm. So not too far off the mark. Head flow may be a bit optimistic though.

Anyhow. Ran with the figures for a VP8C.



the 274 seems like one for an nice tractable motor

Edited by Sam Walters, 15 January 2012 - 03:06 AM.

[PhilipGCaldwell]

when Im rebuilding my other engine I have been looking at modyfying a hoover and constructing a rudementary manometer to try and balance it all properly, its a bit crude but will do the job hopefully

[Sam Walters]

when Im rebuilding my other engine I have been looking at modyfying a hoover and constructing a rudementary manometer to try and balance it all properly, its a bit crude but will do the job hopefully

Knock the centre out of a spark plug, then attach your tube upto that.

This is essentially what im doing Philip. Although i need to get solidworks back onto this new install of windows ive done. Then i can model and make a plate to calibrate the setup.

Although once i can fine a dyno graph of a 1380 knocking out say 100hp with a 276 I can calibrate my computer program to that.

I can calibrate against a 118hp 1293 with a 296sp cam on a hiff44 .Or 125 with a weber 45. But that sort of head is unattainable for a 998. Valve sizes. Plus it will massivly effect low end performance due to the port volume.

Edited by Sam Walters, 15 January 2012 - 06:55 PM.

[PhilipGCaldwell]

sure someone must have a 1380 graph on here for you to use

I take it port volume too big will inhibit performance on a 998 as the velocity of gases is greatly reduced

I have seen people on herer use webers on a 998 but I presume you will need to rev the nuts off them to get the best out of them

[Sam Walters]

sure someone must have a 1380 graph on here for you to use

I take it port volume too big will inhibit performance on a 998 as the velocity of gases is greatly reduced

I have seen people on here use webers on a 998 but I presume you will need to rev the nuts off them to get the best out of them

The issue is its easy to oversize when it comes to induction. Especially the weber style carbs. 40,45,48 and so forth.

People oversize for most applications. The reality is a Hiff44 can be made to flow in n/a form for over 100hp with a CSA of around 1500.

The 40 DCOE has a CSA of 2500ish. Is that extra 65-70% CSA worth it? Considering its drawbacks.

The advantage of the weber is the ability to taylor it much better then many other carbs to the engines requirement.

Solotion? Use one side of a 45. Or even better the progressive weber found on some VW`s.

Edited by Sam Walters, 16 January 2012 - 07:40 PM.

[PhilipGCaldwell]

yes I have seen that before. there is a build thread on here somewhere where he uses a weber and blanks off one side of it

I did have a look at webers a long time ago but was put off by bulkhead mods and I didnt want to use the rubbish swan neck manifold

If I do anything further to the engine it would be to turbo it, but thats pie in the sky really

[PhilipGCaldwell]

MOT passed. Happy days

[Sam Walters]

MOT passed. Happy days

[twrminisport]

ROLLING ROAD>

[PhilipGCaldwell]

yep, ringing up the RR tomorrow to see if I can go next Saturday, happy days, Im a bit upset though because once its rolling roaded it means my project is finished Im gonna miss tinkering