Daimler 250 V8 engine mods

Author
Discussion

dave de roxby

Original Poster:

544 posts

195 months

Saturday 6th February 2010
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Hey V8250,

Thanks for that. Nice motor you had!

I am an experienced engineer but it's amazing what info and ideas this thread has brought up.

As I've said before, massive power isn't exactly what I'm after here. But I do think there is room for considerable improvement on the standard engine by using more up-to-date technology, especially fuel injection. I have always been a classic car nut, especially for Jaguars and have owned plenty (still do - see my other threads!).

But, as one of my final projects (65th birthday comin' up) I want to treat my lovely '67 250V8 to a proper make-over. Got the wires, some Coombes arches etc. I've had all sorts of advice including sticking in 8-litre Viper lumps to adding nitrous injection! Nope, that's not what I'm at. Just want to do one of two things:

either
1) professionally rebuild the existing engine, balance it as you suggest, gas-flow the heads, maybe add custom exhaust manifolds, maybe increase the capacity a bit if that is feasible, but principally to add fuel injection probably with a completely new inlet manifold. Despite some earlier postings, I don't see why 250 bhp is out of reach, maybe a tad more? And I'd probably want to replace the existing manual 4-speed + overdrive box with something a bit more modern.

or
2) might just consider putting in a modern Jaguar V8, at least keeping the heritage in tact.

Grateful for the thoughts and links.

Cheers


jith

2,752 posts

215 months

Saturday 6th February 2010
quotequote all
dave de roxby said:
2) might just consider putting in a modern Jaguar V8, at least keeping the heritage in tact.

Grateful for the thoughts and links.

Cheers

Except it's a Ford engine from the States I'm afraid Dave.

tr7v8

7,192 posts

228 months

Saturday 6th February 2010
quotequote all
jith said:
dave de roxby said:
2) might just consider putting in a modern Jaguar V8, at least keeping the heritage in tact.

Grateful for the thoughts and links.

Cheers

Except it's a Ford engine from the States I'm afraid Dave.
Aside from the fact that it is a Ford block with Jaguar designed everything else built in a Ford plant in Bridgend!

jith

2,752 posts

215 months

Saturday 6th February 2010
quotequote all
tr7v8 said:
jith said:
dave de roxby said:
2) might just consider putting in a modern Jaguar V8, at least keeping the heritage in tact.

Grateful for the thoughts and links.

Cheers

Except it's a Ford engine from the States I'm afraid Dave.
Aside from the fact that it is a Ford block with Jaguar designed everything else built in a Ford plant in Bridgend!
It's still a Ford engine and doesn't have what Dave wants. Original heritage from Daimler.

dave de roxby

Original Poster:

544 posts

195 months

Saturday 6th February 2010
quotequote all

.....Except it's a Ford engine from the States I'm afraid Dave.
[/quote]

Yep, I'm aware of its basis, although I believe well modified and redeveloped for Jaguar. But how far do you take this lineage thing. I personally think every Jag since the XJ40 has looked more like a Ford than a Jag. The X300 did at least get back the faired in round headlamps of the S1,11 & 111 XJ6. But it got cheap Ford door handles, Ford seats, Ford woodwork etc - not a real Jag for me. The original XK8 had its roots in the XJS and Jaguar based Pinin Farina and F Type prototypes (later used as a basis for the Aston DB7) and so looked a bit like a real Jag at the front - never liked the back or the dashbord. But look at the latest XK, undoubtedly a fine car but the front looks more like a Fiesta or even a smiley Transit! But then again, is a present day Aston a real Aston? Actually, if we're talking Astons, I've got to say the little Vantage V8 is the only car to make my mouth water since the E type!

a8hex

5,830 posts

223 months

Sunday 7th February 2010
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OK, I'm intrigued, in what way would you think an Aston is any less of a Ford than a Jag?

The V8 uses the Jag engine.
The V12s are a pair of bogo standard Ford V6s glued together in the middle.

Even when Aston made their own engines sitting in one was an interesting game of spot the parts bin.

I seem to remember from the launch of the V8 that it only shared about 3 parts with Ford engines and that these were things like the sump plug (which is obviously not needed these days).

dave de roxby

Original Poster:

544 posts

195 months

Sunday 7th February 2010
quotequote all
a8hex said:
OK, I'm intrigued, in what way would you think an Aston is any less of a Ford than a Jag?).
I think we actually may be singing from the same Haynes manual here.

I was having precisely this conversation with my son recently. What actually constitutes a 'marque'? He said, it's a bit like defining a football team. The players may be all different from one decade to the next, they may even play at a different ground. But somehow, they are still worshipped as Whatsit United. Its the fans that count.

Maybe it's the same with cars? I don't recognise any Jag after the XJ40 as a real Jag. I might even take that borderline back to the XJ6 S111 or possibly the XJS. Others might say the Mark 11 or any model not created or overseen by Bill Lyons.

But things have to progress. The market dictates that cars have to constantly change to keep up to date with fashion, technology and legislation as well as the actual market which can be fickle. This all has to be financed and so marques are continually being passed to new owners. If the new investor is not an actual car company but, say, a bank or a Russian or Indian magnate, then the marque seems to be preserved. But when one car company takes over another, there immediately seems to be a perceived dilution of the breed. I do think that when Ford took over Jaguar (otherwise it would probably have gone bust anyway!), there was, no doubt, some good input in the way of better production engineering and business practices. Anyone who really thinks that Jaguar or Rolls-Royce car engineering of the 70's and 80's was cutting edge is deluded - miles behind the Germans and Japanese at that time. But my own feeling is that something that defined Jaguar as a marque was lost forever when Ford took over (and they promised it wouldn't).

As for the Jag V8 and Aston V8 and V12 engines, sure they use Ford dimensions as a base. But the so called Jaguar V8 is radically redeveloped from the Ford product and to say that the Aston V12 is two Ford V6's bolted together is miles from the truth. About the only thing the Aston V12 has in common with any Ford is the positioning of the bores, this to take advantage of the existing Ford production boring machines. The V12 block is totally unique, using very obviously differnet rib patterns for instance to cope with the different stresses involved. The crank, pistons and cylinder heads are all different.

Its a bit like comparing a 1956 Jaguar 2.4 engine with a 1986 4.2. Sure, they look vaguely similar, but every damned piece is different.

I am a Jaguar enthusiast through and through. I can just about tolerate that Daimler, who were a totally different outfit, became a part of Jaguar. Whatever, I've got a nice 250V8 and I happen to like like V8 engines, although not exclusively! So I'm going to do this project if it kills me!

The only point I really wanted to make about the Aston V8 Vantage is that, from an overall design point of view, forgetting the Ford connection and despite any arguments as to whether it is a true Aston or not, I find it a really appealing package and, for whatever reason, it inspires me to want one. And that's the first time I've felt like that since buying my convertible 4.2 E-Type back in the sixties!



RW774

1,042 posts

223 months

Sunday 7th February 2010
quotequote all
Dave your wrong mate on so many counts. The V12 aston Does share much with the V6. I won`t labour the point but take it from me that is the case. Re the 2.4 The ends and mains are the same as 3.4 3.8. The B head is exactly the same barr smaller valves , as per the early Mk7, The bore size is the same as the 3.4 and employes the same head gasket.later 240 used the straight port head as did the 4.2, long and short stud variants
Do think about production costs.Every manufacturer interchanges parts to keep the costs down and changes part numbers / ramps up thr price.3.6 AJ6 uses the old XK big ends and so it goes on.
Now get on with that Diamler and stop fannying aboutlaughlaughlaughlaugh


dave de roxby

Original Poster:

544 posts

195 months

Sunday 7th February 2010
quotequote all
RW774 said:
Dave your wrong mate on so many counts. The V12 aston Does share much with the V6. I won`t labour the point but take it from me that is the case. Re the 2.4 The ends and mains are the same as 3.4 3.8. The B head is exactly the same barr smaller valves , as per the early Mk7, The bore size is the same as the 3.4 and employes the same head gasket.later 240 used the straight port head as did the 4.2, long and short stud variants
Do think about production costs.Every manufacturer interchanges parts to keep the costs down and changes part numbers / ramps up thr price.3.6 AJ6 uses the old XK big ends and so it goes on.
Now get on with that Diamler and stop fannying aboutlaughlaughlaughlaugh
A comment had been made earlier, I think tongue in cheek to provoke discussion, that the Aston V12 was merely two V6 Duratec's bolted together which it certainly aint!

As for the XK engine, if you are being pedantic, maybe I was slightly over the top in suggesting there were no common parts between a 1956 2.4 and a 1986 4.2. There may have been a few and the engines are obviously from the same family, having resulted from steady development since the 1940's. But hell, comparing those two iterations, even the cylinder bore spacing is different.

AJAX50

418 posts

240 months

Sunday 7th February 2010
quotequote all
The bore spacing is different on the 4.2 to make room for the bigger bores, basically the same block and the centres on the head are unchanged as the 2.4,3.4 and 3.8
dave de roxby said:
RW774 said:
Dave your wrong mate on so many counts. The V12 aston Does share much with the V6. I won`t labour the point but take it from me that is the case. Re the 2.4 The ends and mains are the same as 3.4 3.8. The B head is exactly the same barr smaller valves , as per the early Mk7, The bore size is the same as the 3.4 and employes the same head gasket.later 240 used the straight port head as did the 4.2, long and short stud variants
Do think about production costs.Every manufacturer interchanges parts to keep the costs down and changes part numbers / ramps up thr price.3.6 AJ6 uses the old XK big ends and so it goes on.
Now get on with that Diamler and stop fannying aboutlaughlaughlaughlaugh
A comment had been made earlier, I think tongue in cheek to provoke discussion, that the Aston V12 was merely two V6 Duratec's bolted together which it certainly aint!

As for the XK engine, if you are being pedantic, maybe I was slightly over the top in suggesting there were no common parts between a 1956 2.4 and a 1986 4.2. There may have been a few and the engines are obviously from the same family, having resulted from steady development since the 1940's. But hell, comparing those two iterations, even the cylinder bore spacing is different.

dave de roxby

Original Poster:

544 posts

195 months

Sunday 7th February 2010
quotequote all
AJAX50 said:
The bore spacing is different on the 4.2 to make room for the bigger bores, basically the same block and the centres on the head are unchanged as the 2.4,3.4 and 3.8
Quite so

RW774

1,042 posts

223 months

Monday 8th February 2010
quotequote all
Agreed. What next??

dave de roxby

Original Poster:

544 posts

195 months

Monday 8th February 2010
quotequote all
RW774 said:
Agreed. What next??
Right! Decision made. Let's forget about other engines. We can muse about them elsewhere. I'm sticking with the original 2.5 Daimler engine - as you say, no more 'fannying' Paul!! OK?? Not that I've exactly been doing nothing over the past 12 month's - oh boy, you'll never know! My 65th looms in April, have a house to clear and get on sale by mid March. May/June should see both the time and funds to get on with the Daimler.

Meanwhile, will yank engine and box out if I can find a moment. Engine will be stripped for full inspection and rebuild. For now, main priority is to decide if I can increase the capacity to any useful extent, within economic reason. As I've said previously, having looked at the drawings, the standard engine looks to have too little meat to simply overbore by very much. Sleeving for any significant increase would involve cutting right into the waterways, effectively converting the block to having 'wet' liners with all the effects on block integity that might entail. But this is where my knowledge and experience stops and I need advice. Could this be done and could it be made to work reliably? I think stroking is probably uneconomic and of no use anyway unless the bore can be increased? Then there's the question of pistons. If I'm stuck with 2.5, sobeit but I need to know.

Let's not go off at tangents here. I need to know if I can or can't increase the cubes before I do anything else.

Meanwhile, thanks to all for the previous posts - most enlightening!

David




mph

2,332 posts

282 months

Monday 8th February 2010
quotequote all
You need to talk to Russ Carpenter.

I think you will find that there are only fairly modest improvements that can be obtained from the Daimler engine if you wish it to remain tractable.

I've lost count of the numerous posts claiming incredible power outputs from various classic engines (not necessarily Daimlers) but these are invariably racing engines where tractability isn't a priority.

Russ Carpenter has obtained 1400 hp from a Daimler V8 and has rebuilt countless Daimler V8's so you would imagine he knows what he's doing. If I recall correctly his road engines have a 10/15 h.p. improvement over standard but he does some reliability mods as well.

I know of someone that's presently fitting a Rover V8 and five speed gearbox to a Daimler Mk 2.

Personally I'd either live with the standard engine with modest improvements and a 5 speed box or go for bust with the majestic major engine.


v8250

2,724 posts

211 months

Monday 8th February 2010
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Hi Dave, since w/e post am now intrigued with thread...modern Aston/Ford/Jag blocks...who cares?! The other guys have rightly stated go for the 4.5ltr Majestic unit, however, spare parts for this are now super-rare...so stick with 2.5ltr and have some fun.

200-250 'reliable' bhp would be no problem with well thought through project. Break engine design into component parts and run the calcs'. Also, don't forget the flywheel (lighten, but not so much as to lose inertia/mass), drill-down on spec' of 5-speed box, static and dynamic balance prop, take close look at diff' spec' and final drive ratios/LSD.

I'm not overly convinced that increasing bore/piston dia' is going to give ultimate results. A little will certainly help, but you'll need to sleeve block with interference-fit top-hat liners. From this drop-in spec'd pistons; maybe with off-set crowns for greater 'swirl'.

One area that's not so easy on the 2.5ltr is the tappet sets and pushrods. Someone had previously developed a hydraulic roller set and titanium rods...this may have been Russ Carpenter or a US team. But this should be looked into, if only for head top-end robustness and accuracy.

Also, we all tend to forget that to make any car faster, the first port of call should be suspension and brakes. I you want some details/tricks send me a p.m. There's a huge amount that can be done within very sensible budgets...b

v8250

2,724 posts

211 months

Monday 8th February 2010
quotequote all
...apologies for not finishing last post...laptop decided to send post all by itself...bloody computers; grrrr!!

...anyway, suspension and brakes - there's a whole host of tricks to do with the v8250 that will make the old girl fly and eat standard 3.8's for breakfast. Plus, on the handling-side, we should all remember the difference in front-end weights between the MKII and V8250.

BTW - where abouts in the UK are you? I'm in Oxfordshire...would be happy to meet up over a beer sometime.

dave de roxby

Original Poster:

544 posts

195 months

Monday 8th February 2010
quotequote all
Thanks v8250. All sounds good sense to me. Grateful for your offer of advice. Will pm you in due course. Meanwhile, being chased by all and sundry re a house sale which will hopefully provide the funds for this project! So may go quiet for a while!
Regards,
David

dave de roxby

Original Poster:

544 posts

195 months

Monday 8th February 2010
quotequote all
v8250 said:
...apologies for not finishing last post...laptop decided to send post all by itself...bloody computers; grrrr!!
Thanks again v8250,
Coincidentally, my bleedin' laptop also playing up! Summut called the 'D' drive full. I didn't even know it had a gearbox! I'm in Yorkshire but get down your way frequently. Would be nice to meet up for a sensible chat.

Cheers,

David

geeman237

1,233 posts

185 months

Tuesday 9th February 2010
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I am not sure if anyone on this thread is aware but a Dart owner is already deep into adding throttle bodies etc to his Dart with the V8 engine. Try this link below to the Daimler Forum. If you use the search function, selecting the Daimler Forum, using Throttle Bodies as the search text and Dart as the poster you should get some results, including photos. There is also a posting with some Russ Carpenter articles from custom car magazines in the 1970's/80's. He does have details on doing a 4 bolt mains conversion.

http://www.dlcentre.com/forum/topic.asp?TOPIC_ID=7...

I have a 1960 SP250/Dart. It is fitted with the saloon version of the 2.5 V8 (minor differences over the SP250 spec engine) and its fitted with the rare saloon manual overdirve gearbox.

I rebuilt the engine last year and made the following 'upgrade's
(1) Russ Carpenter front seal mod
(2) Fitted Pertronix electronic ignition (positive earth version, same as Rolls Royce kit, about 130 pounds)
(3) Bought K&N air filters, but yet to fit these
(4) Fitted a new set of ignition leads from this place (http://www.fastlaneauto.co.uk/)
(5) Had a new aluminium radiator fitted with twin 10" electric fans (ditched the mechanical fan due to fitting of R&P steering)
(6) Had the whole rotating mass balanced
(7) Had the distributer fully reconditioned and rebuilt.

Has it made any difference? Maybe a hp or two.
Here's me enjoying the V8 one Sunday morning....
http://www.youtube.com/watch?v=t8dZGmQa8vc


dave de roxby

Original Poster:

544 posts

195 months

Wednesday 10th February 2010
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geeman237 said:
I am not sure if anyone on this thread is aware but a Dart owner is already deep into adding throttle bodies etc to his Dart with the V8 engine. Try this link below to the Daimler Forum.

http://www.dlcentre.com/forum/topic.asp?TOPIC_ID=7...
Thanks so much geeman237. Very interesting links and info. Oh boy, that SP250 on U-tube sounds good!