Advice on choosing the right engine...?

[mgbv8]

Volvo 5 cylinder Turbo.......

Yep! A cracking engine as well

[The Seer]

Hi
4 bolt mains are 4 bolt main caps on the middle 3 main bearings.
200 runners. . 200 cc runners in the heads.
basically 200cc to 210cc inlet runners and about 23 degrees of cam timing at .05" on a roller cam will give you a road drivable 400 to 420 BHP and a high rise duel plane inlet manifold and a well set up 4 barrel. You then just need to choose the bottom end to "shape" the power curve if you go for a 350 cu inch engine then you will probably see max power at about 6200 to 6400 revs. Put a 3.75" crank in it and it will make a bit more torque but the top end power will be about the same but at about 5800 to 6000 revs find a 400 block and build a 412 cui motor then the same top end will give you about 430 to 440 bhp at about 5600 to 5800 revs, the larger bore makes quite a big difference. Going the other way and you could go down to a 3.25" crank and it would rev well making peak power at about 6600 to 6800 revs but you may have to go to a single plane manifold, and it could be a challenge in traffic, it would still make the same numbers.
There really is no "best" 350 as you can build a 350 cui engine on a 4.185" bore out of a stock 400 block with a 3.2" stroke but finding a 400 block in the uk is not easy.
A 327 block 2 bolt main block can be converted to 4 bolt mains just by getting a set of main caps and drilling the block for the extra studs/bolts.
Avoid 350 blocks post '86 from Mexico as they tend to be porous and have thinner cylinder walls with worse core creep when cast. And an LT1 although good castings are a bit of a pain to use with earlier gen 1 stuff.
best regards
Mike

Many, many thanks Mike Really appreciate the info there. "If" the inteneded Rush does come with the desirable 350 c.i then it would probably be a pre 1986 from what I've seen.

Aside from changing or seriously modifiying the heads I guess I'm looking at better intake manifold and larger carbs too? As mentioned earlier I know nothing anout these engines and as such the tuning side of it as well. Do you have any sort of rough figure how much it could cost to buy all the necessary parts to bring a 350 up to just over 400 bhp?

Thanks

[The Seer]

Why do you want, specifically, an american engine, and, of those choices, specifically a 350 chevy, in a rush?

If you were after a cobra rep, I could understand it more, but a rush is more caterham 7 style. You say you want around the 400 horses figure.... that's a lot for a rush. They weigh bugger all, so 400hp would be 6-800hp per ton depending on final build weight... and a chevy 350 aint that light, so it would eat into the ratio. You may be better looking at bhp per ton figures instead of chasing a specific engine config.

6-800 per tonne are very pleasing figures but I doubt those will appear. A Rush with an iron small block weighs in at around 750 kgs with all the creature comforts and full weather gear. So at 375-420 per tonne the figure would be in the 500 bracket, which is what I'm after.

[The Seer]

I think the simplest answer to your question is that as the iron block chevy only put out a few BHP as per your original post and you will need to change parts to get the horsepower you want then it doesn't matter which of the gen1 iron engines you go for as it'll probably only be the block and sump you keep anyway.
HTH

Thanks for the info Quite a relief there, was concerned since I'm aware there's a few revisions. Makes things easier now.

[The Seer]

400hp in a Dax Rush would be way too much power to be of any use I think !

Whats the point of having power if you cant get it down due to the lack of weight over the rear axle and non slick tyres?

With the right tyres and decent suspension it'll work out ok for me. I don't intend on using the car on track days. It's just for fast road driving here and there and crusing.

[The Seer]

400hp in a Dax Rush would be way too much power to be of any use I think !

Whats the point of having power if you cant get it down due to the lack of weight over the rear axle and non slick tyres?

Hi
I was just plain ignoring that discussion. Really the best engine for a seven is a thoughtfully tuned Zetec or Duratec, alfa or vauxhall 2 litre 4 cylinder engine anything heavier un-ballances the car anything very much lighter is just too skittish.
However I will not discourage anyone wanting to own a chevy on principle and he could always build a 4 wheel drive set up to go with it to get the power down and add weight to give it traction.
best regards
Mike

The Westfield SEiW I used to own had a Dunnel Zetec producing around 180 bhp, the car weighed around 600 kgs. It was fun but it simply wasn't fast enough in a straight line. I'm not fussed about a large heavy enigne up front, I know it'll cause understeer when the car is pushed, but I'm not too fussed about driving it that hard in the corners.

I probably wouldn't go the 4WD route, unless one appeared in the classifieds. I'm not that handy with the spanners and it'd cost a fair amount for to turn the car into a 4WD example despite like the idea.

[The Seer]

Hey!!

I'm not hating. I'm all for sticking stupid power into small cars. But thats for drag racing fun.

If I had one of these cars for road fun I would want it to handle so I would be sticking something like a Fiat 20 valve turbo lump in there. Forged pistons sport exhaust and a few other goodies will see good power. All I did with stock 20v engine was stick a 75 shot of nitrous in to make 300hp. I believe the buyer of the car now has it touching 450hp with better turbo setup.

Horses for courses I guess. If you want to use a V8 then try to get some good wide rubber on the rear end. Something like 10" wide at least I would say

I appreciate a turbo or super charged 4 cylinder engine would certainly be better for the dynamics of the chassis, but it's the charm of the classic American V8 that I really like.

I was thinking the same thing regarding the wheel and tyre combo. The Rush has 9" s I believe as standard, using 245 s. I'd be looking at widening the rear arches and accomodating 11" s with a view to using 285 s or thereabouts.

[kiwicar]

Hi
if you are determined to go for an SBC in a seven then I would start with a good base in a decent block, this would be ideal
http://www.ebay.co.uk/itm/Dart-Little-M ... 2ebd5f4c98
and bore it 4.165" combine that with a 3" throw forged crank and good lightweight forged pistons, JE or Marhl not truck pistons like probe. Add a set of good small chamber heads like these http://www.ebay.co.uk/itm/AFR-SBC-210cc ... 41578bc484 a mechanical roller cam set up with belt drive kit, good roller rockers, I know from experience you want to spend sensible money and buy good kit like these http://www.ebay.co.uk/itm/Jesel-KSS-415 ... 232e5f9638
add good fuel injection, a wet sump good headers and you should have a combination that is fun to drive and doesn't brake traction at every set of traffic lights and can be driven around a roundabout in the wet. The weight of the car really rules out the cheep power options for the small block chevy like a longer stroke 4" bore engine.
best regards
Mike

[Cobratone]

I think he wants to buy a rush with a chevy already in it then modify that engine to get the hp required, well that's how I read the posts. As I said, if he wants that kind of power lots of things will need to be changed so doesn't really matter which SBC powered rush he buys

[volospian]

Buy one with any sbc, take it out and sell it to someone building a cobra, and drop an ls3 into the rush. That'll give you well over 400hp and save ~50kg in weight and probably cost the same overall.

[kiwicar]

Buy one with any sbc, take it out and sell it to someone building a cobra, and drop an ls3 into the rush. That'll give you well over 400hp and save ~50kg in weight and probably cost the same overall.

Yes what you say is entirely true and correct and cheaper and by far the best advice but he says he wants an Gen 1SBC in a DAX rush and more he asks what is the best one to put in there. I don't think he accepts that there aren't any already done to chose from.
best regards
Mike

[katanaman]

My link was really just for information on the various options. I still stand by the If it has to be a v8 and you want that power your looking at an LS engine. An iron block is going to kill the handling. As others have said there are far better engine options that will handle better and less likely to try and kill you.

Like the idea of the 5 cylinder turbo Volvo engine. It's an awesome engine in the Focus RS and a little bit different.

[volospian]

Like the idea of the 5 cylinder turbo Volvo engine. It's an awesome engine in the Focus RS and a little bit different.

Me too, sounds a good plan. What's the size of this engine? I like the thought of the S2000 2 litre screamer, but I believe that's a very tall engine, although it may go in slantways...

[katanaman]

Like the idea of the 5 cylinder turbo Volvo engine. It's an awesome engine in the Focus RS and a little bit different.

Me too, sounds a good plan. What's the size of this engine? I like the thought of the S2000 2 litre screamer, but I believe that's a very tall engine, although it may go in slantways...

They are 2.5l. Easy 300bhp (you can get a factory tune as high as 385) 430 with a bit of work and local guy, a bus driver no less has a dyno printout for nearly 550. He also has a whacking great bill for all the work :-/

[volospian]

I meant dimensions rather than displacement. I was wondering how "tall" it is.