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The right engine for the Frua!

Started by Emmanueld, July 29, 2007, 15:31:36

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Emmanueld

I am in the process of building a new motor for my Frua, this would have probably been the motor of choice for AC or even Ford if cost and Pride!!!! were no object.
   
   Let's start: I bought a 68 original 427 block and I am having a billet steel crank made by Moldex. Rod bearing size will be stock Big block Chevy 2.2" and the small end will be Chevy as well allowing the use of Chevy pistons. Stroke will be 3.98" just like the 428 motor, however I will be using 6.8" long oliver billet connecting rods giving a much better rod to piston angle. The other advantage of using a longer rod is slower piston speed. The net result when combined with the 4.25" 427 bore should give me a 454 motor that can safely rev to 6500 rpm or more. I will be using a relatively mild cam, either solid or hydraulic, I have not made up my mind as of yet but I am leaning toward solid. The goal is 500hp and 550lbs of torque with a very reliable motor which can be driven long distance, I have been told my rotating assembly is overkill for such a motor, but I am lead footed and I would like the motor to be durable. The motor will look almost completely stock on the outside. Only one problem, delivery time for the new crank is 20 weeks!
   
   Emmanuel

kiwi427

Hi Emmanueld,
                 Boy! that is going to be one powerhouse which will really wake your Frua up!
   I admire what you are doing as I guess most 428 owners would not stray away from absolute originality with such a rare car.
   I too love my 427 so I know where you are coming from. Good luck with the engine swap and I look forward to upcoming progress and road test reports.
   
   Kind Regards,
                 Nigel.

runt

Emmanuel, yep the thing which always amazes me when people stroke a 351w out to wait for it ..427 c.i. is the extreme rod angle, anyway that FE sounds fierce; looking forward to further developments!
   
   Paul.[:)]

Emmanueld

The problem with these extreme small blocks is the lack of reliability, 3 to 5000 miles and that's it! They often end with a loud bang!
   
   Emmanuel

runt

quote:
Originally posted by Emmanueld
   
The problem with these extreme small blocks is the lack of reliability, 3 to 5000 miles and that's it! They often end with a loud bang!
   
   Emmanuel
   

   
   Which doesn't seem to have put many people off; 408 or 418 c.i. popular Windsor strokers, I went for 396 because
   a) This would give all the torque I'd ever need..
   b) Didn't want the extreme rod angle.
   
   Paul.[:)]

Emmanueld

I actually like an engine that revs which is why I want to limit the stroke to 3.98" which is standard 428. People are building FEs' with huge 4.2" stroke and more, but they won't rev past 5,000 rpm. Of course the torque will be huge. With a 4 speed car, one wants to be able to rev past 6,000 rpm safely. As far as originality, the 428 was never fully developed, if one wants to make it fun to drive, one has to address a few problem. It's like for the cobra, if you make it better, no problem!
   Most 427 which came with a 428 motor are now running 427s' and most small block cars I see for sale here have 302s' installed. As long as the mods are done tastefully with quality parts no problem!
   I will not install anything on the car that could not have been found in the 60's or early 70's. With the exception of the radio maybe. Even the high quality speakers I found go back to that era. This is one of the reasons I like ACs', nobody is too picky with originality. For some cars, even things like heater hoses, battery cables have to be with the right markings, this is insane! Or the matching numbers scheme, another crazy and silly thing, how many of these high price matching numbers cars are genuine. I know a few vehicles that became matching number cars, when they became valuable, [:D][:D][:D][:D] Of course my mouth is sealed! The good thing with Ford is that in most cases there was no such thing as an engine number, just a date code (with the exception of some K-code cars) which had their chassis number stamped on the engine.
   
   Emmanuel

runt

With all the internal strength of the 427, yes I think that is going to be a magnificent motor, always amazed how many Cobra replica people go for the heavier 460 truck motor, (which won't help the steering..) then stroke that to 514 or whatever..[:0] then again, those are cheaper than side oilers, in the UK people are spending £20k+ on 427 turnkey..!
   
   Saw a 289 Mk3 for sale last year, the original 289 motor to come with the car; presently fitted with a 400 horse ally heads etc 351w, as you say, why not?
   
   Paul.[:)]

Emmanueld

I personally like the 427, good oiling system (Side oiler), great strength at the bottom, relatively light when equipped with aluminum heads and intake manifold (<500lbs), it's just a very good motor. We now have access to some very good aftermarket parts from the like of Edelbrock, Dove, Blue Thunder. It's an easy motor to work on and it can make huge amounts of power and torque. Unfortunately, a little pricier than other big blocks (except for the Hemi). Emmanuel

Emmanueld

Then, if a future owner want to reinstall a 428 later on, why not! there are no engine numbers anyway. I think the car will be so good with the stroked 427 that it would be foolish! It will be mild enough to be smooth and hopefully will last for quite a while. AC used a basic 428 truck engine in the Frua with a 600cfm Holley or Autolite four barrels carburetor, nothing fancy, no Cobra Jet or Super Cobra Jet here.
   
   Emmanuel

kiwi427

Thats right Emmanueld, The original 428 engine fitted to these cars was nothing special in the 428 line up. Just a regular production engine. But even so it still gave excellent performance in that chassis.
   Good idea to keep the original engine in the corner just in case someone down the line wants to revert back to original.
   You won't regret the upgrade. I exchanged the 428 in my Cobra for a 427 and the difference was like night and day! I love the 427's big bore, short stroke characteristics. A deep breathing highly responsive engine. Really more engine than I can safely handle! and the sound is something else!
   Can't wait to hear about yours
   
   Regards,
           Nigel.

runt

That was one of the things which staggered me when reading 'Motor's test of John Woolfe's street 427 (GTM 777F) in '67; the way such a huge displacement motor 'got up on the cam and surged to 7000 rpm..'!
   Surprised to see that these side and top oilers (relatively rare and costly in the UK) are freely available in the States from Southern Automotive.
   
   Paul.[:)]

Emmanueld

Paul,
   
   There are a few companies making new Side Oiler blocks these days, Shelby enterprise makes a modernized aluminum block with six bolts main and Chevy style oiling system, Pond and Genesis make side oiler blocks in cast iron and aluminum, and Dove makes an exact copy of the racing aluminum block of the sixties. Also, all these companies, Edelbrock and Blue Thunder make heads as well. It's becoming more difficult and more costly to find good original blocks these days and the 427 can only be bored .30 over at most. The cost of a new iron block is about $4K and about $5.5K for an aluminum one these days. You still need to spend money in machining as well, not cheap when compared to a Chevy. Dove also makes S.O.H.C. parts, so one could build a new Cammer as well!
   
   Emmanuel

runt

Thanks Emmanuel, didn't realise that, must say those blocks are keenly priced, there is a shift towards originality/period detail across the UK replica scene now, these new 427 mills would find a market.
   
   Paul.[:)]

Emmanueld

Hi, A friend of mine bought a Jaguar C type replica in England, a great car! All alloy, tubular chassis, just awsome! The only thing that gives it away as a replica are the instruments which look too new!
   
   Emmanuel

runt

Emmanuel, that may be the Lynx company, or Realm who also produce the Ram Cobra rep.
   Their XKSS and D Type are stunning too.
   And of course the other difference would be the use of BMW oil seals, so the old XK won't use QUITE so much oil..!
   
   Paul.[:)]