Race Engine Forum UK

Hello Guy...
I bought your book many years ago and still go through it periodically. I have owned 5 Fiat Spiders, here in the States, since 1974. My last one was 1980 FI and owned it for 22 years. It was sold to a friend 6 months ago. Got the bug again and want to build a Totally Fiat Locost. A Locost Fiat should be very unusual here in the States. Have a donor car 1973 or 74 Spider (don't remember what engine it has. It is free and it is in another city) and plan to use all engine, trans, suspension and steering parts possible. My plan is to do it "on the cheap" Left over from my previous Fiat project I have a 2000FI long block and flywheel. The block is prepped, bored and ready to accept new 9:1 pistons. The crank has been turned. Also have the FI head and new 8 valves that are 1-2mm larger (they sell these slightly larger valves here in the states that don't require seat modification) I plan to port the heads my self using your book, lighten the fly wheel and use the 4-2 original cast iron exhaust manifold. My goals are a dependable engine, 150HP+- and 140LBS of torque+- My questions to you are...
1. Can this be achieved with stock cams (have USA 2000Fi cams or USA 1973/4 cams available) or do I need a stage II intake cam?
2. Can this be achieved without resorting to twin carbs (don't want to go the twin Webber route because of cost and complexity) Do they make any carb that will fit the stock single carb manifold that will yield my goal power outputs? (I can even make a tubing intake manifold or modify the single carb manifold if needed)
3. Will the stock 5 Speed Fiat trany & rear take the extra power?

Thanks in advance
Ivan

hullo Ivan, sorry for delay, thanks for the post.

Left over from my previous Fiat project I have a 2000FI long block and flywheel. The block is prepped, bored and ready to accept new 9:1 pistons.

The crank has been turned.

Not a good idea see GC V/W.

Also have the FI head and new 8 valves that are 1-2mm larger (they sell these slightly larger valves here in the states that don't require seat modification) I plan to port the heads my self using your book, lighten the fly wheel and use the 4-2 original cast iron exhaust manifold. My goals are a dependable engine, 150HP+- and 140LBS of torque+

Can this be achieved with stock cams (have USA 2000Fi cams or USA 1973/4 cams available) or do I need a stage II intake cam? Can this be achieved without resorting to twin carbs (don't want to go the twin Webber route because of cost and complexity) Do they make any carb that will fit the stock single carb manifold that will yield my goal power outputs? (I can even make a tubing intake manifold or modify the single carb manifold if needed)

You'll struggle to get much over 138bhp and 140lbf ft on any single carb and the best by far is the (ex Ford Pinto) Weber 32/36DGV (readers please don't run off list of alternatives, this one is by far the most accessible/easiest to set up). Is that enough power in a lightweight like that? Absolutely, it will fly. Cams, keep the standard ones from the EFI. That engine will be very tractable and an absolute joy to drive. Everyone I know who fits competition cams in road cars finds it tiring after a while.

Will the stock 5 Speed Fiat trany & rear take the extra power?
Yes, not a strong box but it will be fine if run with recommended Fiat ZC90 lubrication and providing you give the synchros time to work when changing gear..

GC

Thanks Guy for your kind reply. I will be satisfied with 130HP/130LBS for a Locost. It is a sports car not a race car. I will gladly trade some extra power for single Weber carb/stock cams/NO headers. After your reply I checked the Internet and they stock, in the USA, the 32/36 Weber you suggested...and new it's only $250.00. They also sell a Weber 38 DGAS for $380.00 have you heard of this carb? These are new carbs from the Weber distributor.

Thanks
Ivan

A small note on the subject - the basic 7 kits available here come with very modest power and torque. Around 115bhp/120lbft, the cars are still very, very quick - more than quick enough for ordinary road use. A lazy engine makes these cars enormous fun in everyday use while a peaky tuned engine limits them to track use where you can keep the engine on song.

Ok

For $380 sure you might be able to buy a 38DGAS but I won't advise on that one, it's not a carb I recommend or know how to jet up well. I'd suggest - as previous notes - you go with the 32/36DGV.

GC

The 38DGAS is a synchronised barrel carb ie both open together rather than the progressive action of the DGV. Original fitment on Mk 2 Capri 3 litres it was used as a 'cheap' fuelling modification on Early Ford Pinto engines with slightly better top end breathing but with a loss at the bottom .
I've used both types and would recommend the same as Guy for a sweet street engine.

From Houston eh? I am out in Katy. There is quite a group in our area, you'd be surprised what some people in town have as far as parts for cheap. :) If you need any local help i'd be glad to assist.

For once I am going to heed the expert's advice...a new 32/36DGV for carburation it will be. The machine shop reground my 2L crank and fortunately Guy caught my blunder (see previous entry on this thread). I will have to get another serviceable 2l crank. This past Saturday all the parts were retrieved from said machine shop. The block is bored (and cross honed) for the new pistons. What should the new bore be to accommodate these new pistons? The machine shop does not do Fiats..just being safe. On the box the pistons say 84.8 / Mahle Mondial / NS Riferimento 62.08.4.7750 / Lancia. Can any one tell me what these pistons' compression ratio is? These pistons were bought so many years ago I lost the records. Is this much .8mm over standard OK for the 2L block? Thanks in advance.

Ivan