Winter Projects - Page 43

SAMD · 14 Mar 2011, 11:31 (Ref:2845399)

Quote:

Originally Posted by zefarelly

I actually picked up a load of torque and gained a little mid range power by running a bic biro manifold as opposed to the gas main style a few years ago . . . . pipe tuning is an important part of any decent engine

Did you notice a wee bit about it on the FFord bit last week. A guy on there was saying that his tests showed that oversize primarys were better on a FF engine and that matching the primary size to the port always reduced power. Even when only reduced at the port itself.

"Well I'll bet that you find that the exhaust design has a very significant effect on performance. Before the advent of modelling software such as Wave we had to develop the exhaust systems by the good old fashioned "trial and error" method.
You will find that a 4 into 2 into 1 system will produce a modest benefit over a fairly wide rev band. A 4 into 1, however, will give a much greater increase, but only over a narrower rev band.

For the Formula Fords we manufactured two 4 into 1 development systems. The 4 primaries were arranged so that they could be shortened and the collector would still fit. THe two systems were identical except that one was 1 1/4" dia, the other 1 5/16" dia primaries. Testing was done with varying primary lengths and, hopefully my memory is correct!! we optimised with 1 1/4 primaries at 28" length. Very interested to hear what you come up with. Couple of other points I remember, even though the primary pipe is greater diameter than the exhaust port it works best with the 1 1/4" primaries butted straight onto the head, i.e. the engine likes this step from port to manifold. Tapering the pipe down to match the port size is a real backwards step. This is not just a FF quirk but pretty much common all round. The Formula Atlanrtics showed exactly the same effect. David"
Gungebucket is offline Add to Gungebucket's Reputation Report Post
Quote

zefarelly · 14 Mar 2011, 12:17 (Ref:2845417)

on a precrossflow ports only go to about 30mm for exhaust, 1 3/16" say, I've always thought 1 1/2" primaries ( as the basic sums suggest ) was right, but on a restricted 1500 (FiA engine on 40's) I gained using an old school 1 3/8 primaries.

28-32" total length seems right depending on cam etc, definitely nothing shorter

I butchered a lovely twin cam manifold to make a dyno mule a few years ago

delta · 15 Mar 2011, 17:22 (Ref:2846336)

I have finnished the Steering column. Will post pics late."lost me camera". Also sorted and bought as recomended by MB a heavy duty gearbox mount.Im off to rolling road tomorrow so will drive by Heathrow and collect the propshaft.

HFJ Drifter · 17 Mar 2011, 07:53 (Ref:2847282)

Heres a photo of our winter project, as requested by Iain.
Its the 1962 Alexis Mk4 FJ. Just about ready to go and test at Goodwood on Friday.
Stuart.

**John Turner** · 17 Mar 2011, 09:22 (Ref:2847321)

Now, isn't that just so pretty; well done!

simon drabble · 17 Mar 2011, 09:29 (Ref:2847325)

JOhn it should be - to misquote the M and S adverts - HFJ is not just any coachbuilder.....

zefarelly · 17 Mar 2011, 09:30 (Ref:2847326)

as opposed to the S&M builder with tight belts!

Mike Bell · 17 Mar 2011, 09:32 (Ref:2847327)

Absolutely- Those HFJs are like little jewels and about as pretty as a racing car can get. Hope all goes well at Goodwood!

delta · 17 Mar 2011, 13:01 (Ref:2847446)

Quote:

Originally Posted by HFJ Drifter

Heres a photo of our winter project, as requested by Iain.
Its the 1962 Alexis Mk4 FJ. Just about ready to go and test at Goodwood on Friday.
Stuart.

Grrrrrrrrrrrrrrrrrrr very jealous. Well done Stuart. Stunning Thanks for posting the pic's. Duncan told me not too bother bringing the 22.

HFJ Drifter · 17 Mar 2011, 13:29 (Ref:2847463)

Cheers for the comments, lets hope it works like the Alexis Mk2.
Iain are you going to be at Goodwood tomorrow in the rain?

smokystove · 17 Mar 2011, 15:40 (Ref:2847541)

Quote:

Originally Posted by HFJ Drifter

Heres a photo of our winter project, as requested by Iain.
Its the 1962 Alexis Mk4 FJ. Just about ready to go and test at Goodwood on Friday.
Stuart.

Wow. That's about as pretty as they get isn't it? Great work.

E.B · 17 Mar 2011, 17:05 (Ref:2847594)

Very easy on the eye is that. Hope it performs as it looks, and best of luck for the season.

delta · 17 Mar 2011, 19:48 (Ref:2847702)

Dont worry if its raining Stuart will be in his eliment.Better not say too much but we are still flat out on Compte's Volpini so will not be at Goodwood Stuart. Have fun mate. Also I recomend the ham egg and chips in the cafe.

delta · 17 Mar 2011, 19:52 (Ref:2847706)

Had a lovely gesture yesterday from a fellow race car mechanic. He herd I was building the Escort and has had a Grill in his workshop hanging up on the wall for many many years. Anyway cut a long story short when I went to Baldwins yesterday he had sent it down to Peters for me. Chuffed!!!!!

Robyn Slater · 17 Mar 2011, 20:29 (Ref:2847733)

Quote:

Originally Posted by delta

Had a lovely gesture yesterday from a fellow race car mechanic. He herd I was building the Escort and has had a Grill in his workshop hanging up on the wall for many many years. Anyway cut a long story short when I went to Baldwins yesterday he had sent it down to Peters for me. Chuffed!!!!!

Ah,that was yours ,was it?

I twigged it standing in the corner when i was there on monday.

delta · 18 Mar 2011, 20:14 (Ref:2848455)

All ready for Sunday then Robyn

Robyn Slater · 18 Mar 2011, 20:55 (Ref:2848493)

Quote:

Originally Posted by delta

All ready for Sunday then Robyn

Yep.

184 Baldwin HP BTW

Will you be there?

delta · 19 Mar 2011, 06:36 (Ref:2848667)

Yep ,See you tomorrow.

smokystove · 20 Mar 2011, 16:44 (Ref:2850104)

I have an exhaust tech question for you guys. I have a 50's saloon and the exhaust design is such that the silencer is in the middle of the system, i.e. tubing from manifold downpipe, back a bit then crosses over to the other side where it meets a single silencer near beneath rear passenger footwell, tubing from silencer then travels over rear axle and exits rear.

Two questions: if I were to fit a better free flow exhaust in place of the existing in the middle, would it's benefit be negated by the extra tubing it takes to reach the rear of the car?

If that's the case then I'd just save my money and keep stock system.

Other (maybe silly) question is should this then be a rear or center silencer?

As it's a road car here in Germany it's not technically allowed to change the silencer location, they're strict about these things and I may be stuck with it in the middle hence the conundrum.

Sorry to invade the thread, would ask in classic/road forum but it's pretty quiet in there!

**Tim Falce** · 20 Mar 2011, 16:50 (Ref:2850108)

Smoky, as it's a 50s car are they going to know if you've moved the silencer unless you happen to stumble across an enthusiast tester or a very old tester who remembers how your car came out of the factory?

smokystove · 20 Mar 2011, 17:02 (Ref:2850114)

Quote:

Originally Posted by Tim Falce

Smoky, as it's a 50s car are they going to know if you've moved the silencer unless you happen to stumble across an enthusiast tester or a very old tester who remembers how your car came out of the factory?

Normally, you'd be about right but thing is car is coming from UK to Germany for the first time, so will go through a very detailed inspection not like normal 2-year TüV which is more like your MoT.
This "Vollabnahme" is pretty intensive, had a 60's car which failed simply because I'd fitted an aftermarket header in place of iron manifold. They do this test first and then if passable sent to TüV/Dekka.
So, could it pass if I use a rear silencer? possibly on a lucky day... should it pass? no.

Mike Bell · 20 Mar 2011, 17:12 (Ref:2850122)

Quote:

Originally Posted by smokystove

Two questions: if I were to fit a better free flow exhaust in place of the existing in the middle, would it's benefit be negated by the extra tubing it takes to reach the rear of the car?

Other (maybe silly) question is should this then be a rear or center silencer?

Good luck with the inspection- sounds pretty severe!

Is the engine standard tune? If it is, possibly little to be gained with a 'straight through' box. It's easy to make exhaust too free flowing with big pipe and silencer as above. Back pressure is important as well on a lot of engines. It's one of those subjects complex enough for experts to write books about.........

smokystove · 20 Mar 2011, 17:19 (Ref:2850125)

It is severe, heard a funny story recently about a guy who's classic Porsche rally car failed due to the aftermarket seats not folding forward far enough to safely allow rear passengers to exit.

Nevermind that there was a full rollcage and no back seats, lack of back seats for which it also failed, correct rollcage is permissible though!

Wasn't intending on going nuts with large bore system as it is standard tune, just something that's not inherently restrictive as this particular system is known to be.

jan bot · 21 Mar 2011, 11:14 (Ref:2850494)

Hi there,

Our new project just came in..
Very very excited about it, made a vid!
http://www.youtube.com/watch?v=VbXxGMN71fU
Pics are in there

If you like it, tumb it up!

**John Turner** · 21 Mar 2011, 11:20 (Ref:2850498)

Interesting vid. Effectively a modsports M1 - what would you race that in?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Winter Projects	kickstart	Club Level Single Seaters	27	28 Feb 2006 10:43