Front mounted Engine - Distance Out and Dump Angle
Front mounted Engine - Distance Out and Dump Angle
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Discussion

It's fixable...

Original Poster:

471 posts

226 months

Saturday 18th April 2009
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Just beginning to lay out plans of FED chassis with my mate. Looks like we'll go with about 180" on the long side as this will fit in his garage with the wheels and nose dismounted. I have suggested a plug together chassis like Zane Llewelyn (sp)in which case we will go to about 220" just in case a truly powerful engine is fitted in the future...

Is there a definite calculation by which we calculate optimum distance out for the motor from axle centreline to rear bellhousing flange on engine and the dump angle (degrees nose down or up in the chassis) of the engine ?

We understand that minimum distance out gives best weight transfer at start line but possibly tricky handling further down track and that nose down on the engine means that the engine can be further out but chassis reacts as if it were closer.

Chassis will be planned to fit BBC/PG, but previous debate about Rover still raging and it looks like the Rover will be the first choice....

Any feedback gratefully received.

Cheers

Jon

NuthinFancy

229 posts

232 months

Saturday 18th April 2009
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Your best bet is to post this on the technical forum on www.classicfunnycarboard.com

They have tons of blown alky / blown nitro slingshot drivers, crew, tuners, chassis builders. They aren't scared of sharing information with you either they will be really useful.

Or put it up on www.insidetopalcohol.com ,a large amount of professional chassis builders post there, including the likes of the Parks of Neil & Parks who build most of the VRA Nostalgia slingshots. Again, always keen to help people with their projects.

Edited by NuthinFancy on Saturday 18th April 11:47

NitroWars

667 posts

232 months

Saturday 18th April 2009
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There are more than just Zane's like this including Steve Johnson's Motor Mouse and Martyn (Syd) Jones' new dragster which is worthy of an engineering award!

fester426

272 posts

217 months

Saturday 18th April 2009
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All these measurements where relevant as the cars progressed 40 years ago.Now most customers want there car built to look like a certain car from a certain era.A big factor in the evolution of these cars was approx 800 horsepower,then direct drive could work enabling the engine to be pulled right back to the axle line,some cars even had to trim the rear exhuast pipe to clear the tyre or blow smoke from it.At the end of the day pick an era that you love ,,,,me personally its priddles 6.04 car so any slingshot built for myself would have to have those asthetics.Ive just finished a full bodied short wheelbase 2 degree nosedown blown car for a customer because thats what he wanted.Now the horrible bit ,,if your using a rover engine then it really aint gonna matter,what wheelbase ,engine out ,bubble combination you use beacause it wont make enough power to overide the chassis,when a customer has 2000 plus horsepower then you have to be carefull with these measurments.As a sidebar,the excalibur car came to me as a complete chassis ,but we moved the engine back 4 inches and changed the roll cage for a softer older look,at the end of the day its a looks thing ,go to ,,,,we did it for love,,website pick a car that gives you the horn every time you look at it,,,and build that one,,,,,all my love ,,bill

veryoldfart

1,739 posts

226 months

Saturday 18th April 2009
quotequote all
fester426 said:
All these measurements where relevant as the cars progressed 40 years ago.Now most customers want there car built to look like a certain car from a certain era.A big factor in the evolution of these cars was approx 800 horsepower,then direct drive could work enabling the engine to be pulled right back to the axle line,some cars even had to trim the rear exhuast pipe to clear the tyre or blow smoke from it.At the end of the day pick an era that you love ,,,,me personally its priddles 6.04 car so any slingshot built for myself would have to have those asthetics.Ive just finished a full bodied short wheelbase 2 degree nosedown blown car for a customer because thats what he wanted.Now the horrible bit ,,if your using a rover engine then it really aint gonna matter,what wheelbase ,engine out ,bubble combination you use beacause it wont make enough power to overide the chassis,when a customer has 2000 plus horsepower then you have to be carefull with these measurments.As a sidebar,the excalibur car came to me as a complete chassis ,but we moved the engine back 4 inches and changed the roll cage for a softer older look,at the end of the day its a looks thing ,go to ,,,,we did it for love,,website pick a car that gives you the horn every time you look at it,,,and build that one,,,,,all my love ,,bill
mmmmmmmmm Mr Revell and Mr Six.....


PhilSweeney

111 posts

210 months

Monday 20th April 2009
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As Bills said, if your building a car to look like it ran 45 years ago, your building in features which we're introduced to overcome issues of the time, most notably tyres, track surface and gearing. With modern tyres and prepped tracks, tractions not really going to be your issue, wheelstanding will be (if you intend to leave at a decent rpm and in my view from idle sucks), so build it long, use heavier gauge material in the front of the chassis and provision for a weight bar, then you can go to a bigger motor when without building virtually a new car.

if you go for a glide, build it with a shorty, nothing worse than a nice slingshot chassis and the motor too far from the rear wheels. If you want to be authentic, check out this article http://wediditforlove.com/techtalk18.html . Can't stress how much of a false economy a Rover is...

For me, the Masters and Richter car and the sister car was used in More American Graffiti was the best proportioned car, open front rails, chutepacker body, runs a small block in the film but I believe had small and big blocks chevys before a Hemi http://www.paullemat.com/dragster.jpg, perfection. If I could have somebody build me that car for a reasonable price, I'd sell my altered in heartbeat.

It's fixable...

Original Poster:

471 posts

226 months

Wednesday 22nd April 2009
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Bill, Phil, thanks for the wise words.

OK will forget dump angle and plan for level install on engine/gearbox.

As for distance surely long glide will not make engine too far out ?

PhilSweeney

111 posts

210 months

Wednesday 22nd April 2009
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I'd build in the dump anbgle if thats the look you want, I think it looks great with a rake on the motor, theres just nothing to gain from it really now.

Depends how you like your slignshots to look, the glides not a big box, but consider the box and couplers length and in shorter car the motor looks too far out. All about proportion I guess. Personnally if I go back to a slingshot again, it will have to look right and for me thats pulling the motor as far back as poss. Using a shorty box does make pedal placment harder as well though.

It's fixable...

Original Poster:

471 posts

226 months

Wednesday 22nd April 2009
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Phil,

Potential driver is about six foot tall so we'll need a bit of cockpit space !

Luckily he doesn't have my size 13 feet though !

Jon

MotorPsycho

1,126 posts

232 months

Wednesday 22nd April 2009
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its all about stance, I personally love a slingshot with the motor tucked far back, low leant back cage and a bit of nose down on the motor - motors sat far out and level just look a little unplanned

fester426

272 posts

217 months

Wednesday 22nd April 2009
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Its interesting to hear other people talk about looks and stance,its nice to nknow im not the only nutter out there that worries about what something looks like.Im not talking about modern cars which are bassicly generic and are only seperated by paintjobs,but olderstyle layout cars where the look of the individual parts make for a complete package,WAKE UP ,sorry sorry.Right where was i ,oh yes take the cage on a slingshot its the most in your face thing and hard to get right,but when its wrong it does acctually look very very wrong.Any car you build should be able to live in your front room so that you see it every day and think ,wow i own that.However you do still find people and customers that,,if you stood them in front of the beebe and mulligan car and somehidious creation made over here thay couldnt tell the difference,they would say something like,,,,what?there both cars 2 whheels at the front 2 at the back ,then you would say or point out how the pat foster body work flows in one gracfull curving arc fitswith one beautiffly fitted dzus button which is in perfect line and symettry with the next,and the other car has tinwork fitted by a blindman whos labrador has died and is held on with bolts (all different,some rusty)they would not see the difference,honest,,ive witnessed it,,,smilethis is not aimed at anyone ,just an observation of people,,,,sorry i meant philistines,,and before you say it ,its all very anal,,,,,,please look at ,,we did it for love,,theres some dogs mess in there as well but most of the cars are absoloutly iconic,,,,,,,sits back and waits for the abuse ,like who the fk does he think he is etc etc etcsmile

Edited by fester426 on Wednesday 22 April 21:56

anonymous-user

75 months

Thursday 23rd April 2009
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It's fixable... said:
Just beginning to lay out plans of FED chassis with my mate. Looks like we'll go with about 180" on the long side as this will fit in his garage with the wheels and nose dismounted. I have suggested a plug together chassis like Zane Llewelyn (sp)in which case we will go to about 220" just in case a truly powerful engine is fitted in the future...

Is there a definite calculation by which we calculate optimum distance out for the motor from axle centreline to rear bellhousing flange on engine and the dump angle (degrees nose down or up in the chassis) of the engine ?

We understand that minimum distance out gives best weight transfer at start line but possibly tricky handling further down track and that nose down on the engine means that the engine can be further out but chassis reacts as if it were closer.

Chassis will be planned to fit BBC/PG, but previous debate about Rover still raging and it looks like the Rover will be the first choice....

Any feedback gratefully received.

Cheers

Jon
Just my 2p worth:

It doesn't cost any more to go to town in the looks department, regardless of what powerplant you use. Admittedly, a Rover lump is a false economy, as no amount of money will help it produce the amount of power that a small block will, on a smaller budget.

Two piece chassis work well in RED applications, but a FED works in a different way - the car needs to bow in the middle, and logically, that's where you'd put the break. Having said that, if the powerplant isn't something silly, you could get away with it I imagine.

The dump angle on the motor is something that seemingly gets ignored on the 'newstalgia' cars. However, the current crop of nostalgia fuel and alky FED's have a mixture when it comes to angle of dangle. From memory, the Chevy sits 5 degrees nose down, which makes it look quite menacing (which I like).

As mentioned above, the trick is to find a car from back in the day, which looks right to you, and take the features you like and apply it your own car.

Bassline evolved from being a 125" Poison Ivy clone, into a Croshier-Baltes-Lavato crossed with Vagabond.





I'm chuffed with the result, and it came out better than I ever thought possible. So - if you have a clear direction you want to go, and can show your chassis builder what you want, anything is possible smile

It's fixable...

Original Poster:

471 posts

226 months

Thursday 23rd April 2009
quotequote all
Jon B,

The whole point of these questions is that we want to be the chassis builder and do not wish to farm the job out.

We'd like to think we have the skills and the eye to build what we want.


Bill,

Take your point about aesthetics; what looks right generally is right...


Cheers

Jon

PhilSweeney

111 posts

210 months

Thursday 23rd April 2009
quotequote all
It's fixable... said:
Phil,

Potential driver is about six foot tall so we'll need a bit of cockpit space !

Luckily he doesn't have my size 13 feet though !

Jon
yeah thats not gonna help, he's no jockey is he ! I'm 5ft 10in and struggled a bit in my slingshot but it was built by somebody 5ft 6in. I'd put more angle between the shoulder hoop and bottom rails, be careful though as I think theres a maximum angle if you're trying to tag it.

fester426

272 posts

217 months

Thursday 23rd April 2009
quotequote all
The big majority of those old beautifull cars where what you would now call a homebuild,find the look you want and go for it ,dont be swamped by what other people ie us and me sayrolleyes

topnitro

237 posts

259 months

Thursday 23rd April 2009
quotequote all
It's fixable... said:
Jon B,

The whole point of these questions is that we want to be the chassis builder and do not wish to farm the job out.

We'd like to think we have the skills and the eye to build what we want.
I hope that when your car-building exertions are complete and when the project expenditure is over and you've finished your Front Engined Dragster; that the finished car a) Looks as pretty as and b) Sounds just as loud and as crisp as...

This one:-


..then you will truly have achieved something remarkable and worthy of the highest praise.

I look forward to seeing this car when it is finished.

In the meantime, so much for "Any feedback gratefully received."

fester426

272 posts

217 months

Thursday 23rd April 2009
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What a good piccy ,havnt seen that one its very flattering,the best pic of it ive seen

Furyous

25,230 posts

242 months

Thursday 23rd April 2009
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Fab pic sir, lovely atmosphere.

It's fixable...

Original Poster:

471 posts

226 months

Friday 24th April 2009
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Topnitro,

Why "so much for any feedback gratefully received" ?

I hope this project will come to something and there will be a thing of beauty to show at the end of it. I've been asked to be involved by my mate and will try to assist him as possible and let him know what I think is race legal, sensible and correct. He has the funds, we have the skills and facilities, it's a question of whether he has the staying power to see this through and whether he will listen to sense or not. I'm not interested in puttng my name or efforts into a monstrosity like Bill describes in his earlier post.

All I've done is clarify to Jon B that we want to do the job ourselves, not farm it out. viz Jon's quote "if you have a clear direction you want to go, and can show your chassis builder what you want, anything is possible".

I feel that Jon B has achieved much during his involvement with drag racing, whereas I in an involvement lasting much longer have achieved nothing of account.

Therefore I continue to welcome constructive feedback or critique from all to this question or any other.

I am not seeking to have an argument with anyone or piss on their achievements and I am also not happy to have insult attributed to me where their is none. Accordingly I'd be grateful if you'd allow the person you obviously perceive that I intended to insult to reply for themselves rather than wading in on their behalf.

Jon


It's fixable...

Original Poster:

471 posts

226 months

Friday 24th April 2009
quotequote all
Oh, and by the way Richard, that is a top photo of Bassline in your post.