Which V8 to choose

[cupra]

Hi,

Just bought the first stages of the CanAm. Really exciting - I am finally building the car I have been drewling over and talking about for years. I am busy making the last configurations - dream big!

Any advise you guys can give on the American Speed engines (or other SB's), to someone who comes from the world of high-powered and high-rev'ed compacts?

B

[Boosted Ls1]

The new engine on the block with a very bright future is the chevy ls1/6/2/7 and it's got bigger block options. You must have heard of it?

Boosted.

[crafty]

Hi Bjorn,

Congratulations on the purchase. Obviously someone has directed you to this site, and there is a wealth of information here on Ultima building.

If you search the threads you will find the matter of engine choice discussed in depth, it is a very common question and one of the more exiting ones that must be made along the way.

You can also check out the sticky thread with many build sites on it:

www.pistonheads.com/gassing/topic.asp?t=52994&f=20&h=0

There is also a load of info on gearbox choice.

Welcome and I wish you all the breast luck for the new venture.

GC

[G Man]

cupra said:

Hi, Just bought the first stages of the CanAm. Really exciting - I am finally building the car I have been drewling over and talking about for years. I am busy making the last configurations - dream big! Any advise you guys can give on the American Speed engines (or other SB's), to someone who comes from the world of high-powered and high-rev'ed compacts? B

Hi Cupra

I run the 377 ci world record 0-100-0 holder Ultima, firstly an Ultima is very light at approx 1000kgs, the porsche gearboxes are low geared so you do not need a SBC that has a tonne of torque at 500 rpm, my gearbox works out to be 27mph per 1000 rpm so to do 200mph it needs revs

The base engine from chev is a 350 ci or 5.7 ltr engine, this is revvy and unless you are mad will scare the living daylights out of your friends. A 377ci is a bored out 350ci and it really revs hard and fast.
A 383 is a stroked 350 etc etc. A SBC has a 21degree head on a std engine, aftermarket heads reduce that angle from 18 , 15 and 12 degree these increase flow and therefore power. A 377 uses the 18 degree head and therefore a different exhaust system from the factory

Ultima factory recommend American Speed for a reason, they produce good engines that fit, including all the pumps and alternators. The ls range of engine are good as well but you are away from standard so it depends on you build skill if it high OK if not stick to the factory stuff you have been warned !!

Personnally if I wanted up to 500 bhp I would go for an AS 350ci if I wanted power a 377 is where its at, if I wanted an ls engine, go no further than ls7 crate engine ... 427 ci

PS I have no axe to grind, I have a car unlike others here and I am not a dealer of engines

[peterpsg]

G Man said:

A 377ci is a bored out 350ci and it really revs hard and fast.

IIRC a 377 is a destroked 400ci block, G' have you got some kind of wierd set up ???

I run a 383ci, which as G' says is a 350ci block with a stroker crank, i.e the pistons travel further down the bore as the crank has a wider turning radius, this gives somewhat better torque, as there is more leverage on the crank, but perhaps a reduced upper RPM limit, still, mine is chipped to stop at 7000rpm.

The 400ci block is rarer, and thus more expensive to source a good one for the engine shops, but is prefered for the higher rev applications like G's because the wider, but shorter stroke has somewhat better breathing at hi revs than a narrow but deep (torque producing) stroke like mine has. Of course, if you add turbo/supercharger or re-ratio your gearbox...

As you're in Belgium, you might have to meet Emmissions regs? So an LS engine will be the way to go with all the ancillaries.

[G Man]

You are correct a 377 can be a 400 ci block with a 350 crank installed or a 350 ci block bored out to 4.125 inch IIRC

[mick3214]

Hi Gman
How did you get round the emmision test when you mot'd your car, are you running cats

>> Edited by B-Man on Tuesday 21st February 10:27

[G Man]

My car requires a visual test only as per it states on the vehicle reg doc. But the exhaust I have which are factory standard now for 18 degree heads can have cats installed within the exhaust box, this is a special though

[B-Man]

G Man said:

My car requires a visual test only as per it states on the vehicle reg doc. But the exhaust I have which are factory standard now for 18 degree heads can have cats installed within the exhaust box, this is a special though

That must be an SVA thing, that's cool as I was worried about having to fit cats and all the aggro that go with them, I was on the understanding that all vehicles had to have a cat test unless they were classed as agricultural ie a 4X4 from year 1993 onwards

[G Man]

It depends which engine block you have a pre 1970 something tink its 1974 and you don't require CATs.
Engines supplied by American speed are done like this with appropriate documentation. Fit a new LS engine and you will need CATS not impossible but it needs to be done right

[peterpsg]

G Man said:

You are correct a 377 can be a 400 ci block with a 350 crank installed or a 350 ci block bored out to 4.125 inch IIRC

Is there much 'meat' left on the Cylinder walls? Or is the bigger block just have bigger
holes to start with?

IIRC, the 400 block has larger main journal bearings to help with the extra power perhaps.

[chuntington101]

i thought you were runining a ally block though Gman???????

does this stilll only requoier a visual check??

Chris.

[G Man]

chuntington101 said:

i thought you were runining a ally block though Gman??????? does this stilll only requoier a visual check?? Chris.

I have an early ally block from the 70's

[fastco]

Hello point on Chevy 400 blocks all are simease bore blocks this means cyln bores meet in the middle of the side of each bore & there is no coolant running between each cyln bore... this causes cyln bore hot spots & wall distortion @ increased BHP levels & the 400 blocks are prone to head gasket failer between cyln bores because the heat there & there is very liitle material for gasket sealing between cyln bore.. Fel-Pro's pro series o ring head gaskets seem to keep this in check.. other option is to 0 ring block deck.
Cyln wall cooling may be increased by rifle drilling between cyln bores, a tricky operation for pros & not novice machinest.
Also 400 Chevy 4 bolt main blocks are prone to main cap failer/ cracking due to outboard main cap bolts that break into water jacket of block & since the main journals are +.100th larger dia then the 350 block there is reduced main cap material/ strenghth this can lead to main cap walk/ shifting these are a weak spot of these blocks... we recommend using a 2 bolt main block & converting it to a 4 bolt main block using splayed billet main cap kit eg: Milodon
I recommend the 350 Chevy block for street & track driven engines, with ultra lightweight crankshafts & lite 4340 I beam rods & ultra lite pistons &
6.250 dia lite weight fluid damper, this reduces reciprocating & rotating mass weight & produces a very quick rev'n engine & high RPM HP in the 355 & 7500+ RPM in the 383 stroker engines.
Were track & road testing a 383 now on the west coast & shes a beast @ 550+ BHP.

My 2 pence/cents Dr,Dee


>> Edited by fastco on Tuesday 21st February 13:50

[cupra]

I must have landed in the right forum here. It all started out as a general and very simple question about high rev'ed V8's - and a couple of replies down the line its already a triggering intense discussions on stroke, rare 400 ci's and emissions. This is really really good. Thanks for the inputs.

Gail from American Speed also instantly recommended me the 377 or 383, and still agreed when discussing the supercharger (cause I want one) - but I started to see the big black pit that eat money widen even further when he started talking about titanium heads. So now I gotta find the magic compromise between rev's, BHP and cost. From what I can see on other engine configurations on American Speeds homepage, it seems as I can get about 6500 rpm/500+ BHP without too many expensive upgrades.

Now for the next 2 questions:

Any advise on supercharger. I'm real turbo-head, but know very little about superchargers. For the ultima, a topmounted superchager seems to be difficult to fit and only possible on engines less than 383ci.

I'm all for EFI's and carmanagement systems. The intention is to mount a server in the car, and run all electrical, I/O and ICT controls from that. EFI has not been too advanced for American V8's, but its picking up. Any advise on the best fit for an American Speed.

[chuntington101]

well on the supercharger front i would go with a ati ProCharger. they can support anything from about 500bhp to around 2500bhp (!) but the big ones dont fit the ultima! lol

i would go for the D-1sc as these are good upto about 900bhp. als read an article (if you going into link on the Prochager page i think you might fine them) on one shop/mag building a 355 that was putting out over 700bhp on pump!!!! and it wasn't anything special!

the problems comes when trying to cool the air! there isand much room or airflow of intercoolers and chagercoolers could be difficult to plumb in. you could go for water/methnaol injection. alot of the us guys have had succes with this.

hope that helps some,

Chris.

[CanAm Dave]

Hi Bjorn

I am in the process of fitting an ATI ProCharger D1-SC supercharger to my CanAm. It will also be fuel injected. You can read more about it on my website www.v8yes.co.uk
But here are some pics to get the ideas moving.





Regards Dave




>> Edited by CanAm Dave on Tuesday 21st February 19:55

[jschwartz]

Use an LS based engine,aka Gen3 small block.
Cylinder head flow is far superior to gen 1.
Gen 1 small block chevy's will soon be looked upon like flatheads.
Of course we build whatever the customer wants.
Jeff S
www.schwartzperformance.com

[Boosted Ls1]

Of interest is it a test to see if a Cat's been installed or an emmisions test to see if the car's clean? If the emmisions are clean do you need the cat?

My saab after 93 and I've removed the cat, my mot tester says if it passes the test it doesn't have to have the cat fitted.

Also, the lsx is a clean engine. The top ring land is only about 5mm thick offering a reduced crevice volume for unburnt fuel to hide in. There are other 'clean' features with this engine. It's been a big leap forward compared to earlier engines.

Boosted.

[cupra]

CanAm Dave said:

I am in the process of fitting an ATI ProCharger D1-SC supercharger to my CanAm. It will also be fuel injected. You can read more about it on my website www.v8yes.co.uk But here are some pics to get the ideas moving.

Dave,
thanks feed back. Your engine room looks really cleaned even with the extras. The charge cooler looks really nicely fit - guess it took a while. There's an American car-crazy engineer at work, who also talked about the ATI charger, so maybe I should look more into that.

I am also looking for EFI. Saw on your homepage you've got a Holley EFI. I have been told they go to about 500BHP, and that's about what it can do. Is that the Aeromotive gear that improves the performance?

Bjorn