Another option would be a 450hp 347 stroker, ~100lbs lighter than a 351 based engine.

Have you looked at the Mass-Flo EFI? 1000cfm throttle body MAF system based on the Ford EEC. Very trick.

 

Yep a 347 stroker is another option. I just always been partial to the 351W for some reason.

I looked at Mass-Flo its very simmilar to the Edelbrock Flopro2 but its all self contained where as the Flopro2 has an external box you have to tune.

To be honest I like the 4bbl carb look but lately I have been leaning back to the racy style EFI stack system that looks like those old Webber downdraft carbs. Might be alittle more pricy but it just looks right. Its just like how the new ford 4.6L would look out of place in a AC Cobra.

 

Oh no.. you're completely missing the most important factor of using a larger displacement engine and why it will be much much harder to drive than a 289. It's the torque.. the amount of it and where it happens in the powerband. A Hi-Po 289 revs to 7500rpm and makes peak TQ of maybe 350ft/lbs way up at 5000rpm or so, in comparison a 408 will make 500+ft/lbs and all that comes onboard at 2000-2500rpm at most. The difference this makes is that with the 289 you can throw the car into a corner and mash the throttle to the floor and leave it there and not have to worry too much about overpowering the tires until you are through the curve and the motor has had a chance to spool up a bit. With the 408 you will have enough grunt to overpower the tires at almost any speed and engine rpm so you will literally have to feather the throttle all the time or the back end will just go up in a cloud of smoke. If you want a car that's easy to drive fast this is not the motor you want, but if you want one that is built for effortless drifting the 408 is the ticket.

 

You are right, the 289 powered version was rated at 390hp @ 6,750 rpm and 341 ft lb trq and didnt list the rpm for that. But even Shelby was crazy he had a Type 65 coupe in the works that was to be powered by the same 427 that the AC Cobra`s had.

DD2000 was showing my trq with the 351W build I had in earlier in the post as showing 400 ft lbs @ 2,000 rpm on up to 495 ft lbs @ 4,500 - 5,000 rpm. The 408W stroker (alittle more compression 10:1 vs 9.88:1 and same camshaft) is showing 470 ft lbs @ 2,000 rpm on up to 537 ft lbs @ 4,500 - 5,000 rpm and using Keith`s 210cc heads its 460 ft lbs @ 2,000 on up to 550 @ 4,500 and 560hp @ 6,000 rpm

So I am in one of those situations where I would like the 408W stroker but I also want a 351W with the factory perfect rod ratio. So I am at a loss right now and back in my old ways of wanting to just build it up as much as possible and not building it to the vehicle. I know Keith doesnt offer a 351W short block he offers a 347 stroker short block or the 408 - 410 stroker short blocks. So I am just wondering if I did do the 408W stroker could I make it alittle better powering out of the turns by going from 3.55:1 axle ratio to say 3.27:1. It might make the engine boggy since the cam is listed for 3.55 or lower axle gearing.

I talked to one of the guys on the forums that built a coupe hisself and he stated that with the 380 - 400 hp 351W he has the thing is a blast to drive and can easily accelerate in 5th gear on the highway without having to downshift. I just dont know if you could build a 408 stroker to make less than 500 lbs of trq. Like wise I might be back at my old position of building a 351W or contact Keith to see if he could build a 351W short block for street/performance.

I figured up trq to weight ratio and this is what I came up with

Orignals : 0.33 ft lbs / Kg
Mine with 408W stroker : 0.44 ft lbs / Kg

Mine is slightly heavier than the orignals being at 2,500 lbs where the orignals were 2299 lbs

Maybe I should just look towards some 289`s or 302`s. I dont know if I could make 400hp out of a 289 without having to run a very high compression ratio.

 

400hp from a 302 is no problem at all these days according to AFR, they hit that using nothing but a set of their heads, exhaust, and 1.7 rocker on an otherwise stock 5.0HO bottom end. That's a ~9:1 motor running on pump gas!
400 HP 302 ci AFR 165 cc(Stock Cam)

And if you want to increase the entertainment factor a bit go to a 347 stroker, you get a much broader TQ curve and greater HP potential without incurring the additional weight of the 351 block. This stroker also has the benefit of smaller main journals(compared to the 351) which are considered by some to be favorable for extended high rpm operation. This motor is probably the sweet spot for a replica roadster like this that is more personal entertainment than full on racer, you maintain the original chassis balance and handling but have a substantially stronger motor with more "show off" factor than an exact replica would have.

 

The guy who I was talking to has a 385hp 351 and he said that with these cars 350 - 400 rwhp is plenty for the avg guy. He also said if he were to do it again he might think a 347 stroker. Only problem is if I do change my mind I will have to redo my parts list cause everything is for the 351W and I know their the same family as the 289 and 302 but being taller deck and wider some things just wont interchange.

Another guy I was talking to on the forum got a chance to drive Todd`s Kirkham, which has a 482 FE (4.25"x4.25") and he said that it had more low end trq than anyone would need and that he never felt like he was going to loose control over it. But he did say that alot of it has to do with throttle linkage and modulation. So maybe just maybe I could still go with the 408W stroker I would just have to be careful and learn the vehicle and learn the throttle modulation. I will have to talk with Gordon though and see what he thinks, hes into building these things up for racing and selling race style parts. He will know exactly how it would handle with different amounts of power.

P.A.W. how ever I see does offer a prepped 289 block but nothing else.

I also started thinking about the exhaust. Maybe this 408W will make 500hp and 500 ft lbs of trq on a dyno but that is using equal length headers. Not the restrictive 2 into 2 headers or the quad side pipes. So in reality that will choke the engine down I also have to do my research on that to see how much power loss is to be expected with those headers and side pipes. The 408W might really be putting out 450 hp flywheel with that exhaust system.

You are right about the 347 though that lots are using them. There are some going crazy and dropping in 427 FE side oilers in the roadsters. But the one thing this coupe has over the roadster is a longer wheelbase and more balanced weight distribution front to rear.

 

Yeah that's what I have heard too, my friend with the 5.0 notch has collected another complete 5.0 powertrain for a Cobra replica(SuperPerformance) he wants to build, all reports are that even a stock 5.0HO is pretty entertaining in these little cars. I would also like to build one some day and I think I'd go with a 347, I'm kind of torn between the Cobra and GT40 though.. tough choice.

 

Thats how I am, after I got on the forums my plans and finished product ideas have changed like 4 times. I was orignally going for a modern day version of the race coupe of how it would be built today using the 1960`s body style. Then I changed over to building it like something from the 1960`s but with hidden modern upgrades. Then I found that I could get a 408 stroker short block for $3,000 ready to go just bolt on heads, intake and ignition and your done. But with seeing that 408W stroker video I am like yea that would be fun but I dont think it would be safe to be drove on wet roads especially on the highway with wet roads.

But if I can find a 289 block kit or a rebuild kit for a 289 I might would go that route but PAW is just so damn expensive on their bare blocks. Their 289 bare block is $2,500 or so and I can get a 408W stroker short block ready to go for $3,000.

I do know the finished product will have A/C, a saden type compressor in a black powder coat mounted low on the passengerside slightly above the crank. Then a black alternator mounted slightly higher above the compressor but below the water pump for maximum belt to pullet contact. I was also going to go with a remote mount oil filter mounted infront of the engine for easil oil changes. Then the outlet of the remote mount filter will go to the passengerside alittle bit before hooking up to a oil cooler mounted in the radiator duct behind the radiator. Which will then flow back to the engine. I was also looking at a corvette Harrison burp tank which was the same one the orignal 289`s used. Not sure how one would go about hooking it up since those orignal radiators had a pipe mounted in the radiator tank to force some coolant into the burp tank while running. The dashboard would be laid out like the race version with the 180 mph reverse sweep speedometer mounted centerline above the console. The A/C vents would be black powder coated ball vents with a single bar which would look very simmilar to the orignals which was a hole in the dash with a flat difuser bar in the middle.

I am trying to go for the vintage race look to be honest so when I pull up to the gas station during the break in period people would be like WTF when I check everything under the hood. Thats another thing I need to find out if the summit reuseable AN hose ends are compatiable with regular old black rubber hose. The stainless steel mesh looks great but thats not 1960`s race thing. But I will go with it if I have to to run supperior AN fittings.

I just thought of power loss through the drivetrain. People keep saying 20% loss between the flywheel and the rear wheels. In truth different transmissions loses different percentage but I just figured up 20% on 500 hp that is a 100 hp loss. God if thats true that means 400hp/trq would be at the rear wheels. Surely you dont lose that much with a TKO600 and 3.55:1 IRS when a 2spd powerglide only loses around 15% by itself.



~Update~
I have been doing reading on the forums. Both about hp/trq as well as traction and even looked up some 408W topics to see what people were saying. Basically people are saying a race engine in one of these cars for street use is a pain. Now I didnt pick out race type parts, I just picked out parts that would give me a racy lope but give me good efficency. Aside from that one guy was saying with the 408W he was getting 22-23 mpg out of it and he uses a 0.64:1 OD TKO 600 with a 3.27 rear axle ratio which put 4th gear to a top speed of 145ish mph. Also said a 408W wouldnt mind being lugged down to 1500-1800 rpm in 5th gear on the highway.

But after reading all that I am just saying screw it to the 408W. Thinking about it, its nothing but bragging rights to be able to say 500 hp. I could even say 500hp out of what ever engine I put in there due to the light weight. But now I am looking at either a slightly warmed up 289, 302, or 351W. Any of which I go with will have to have that race car lope and 10:1 compression for that deep race car sound but I am thinking EFI with smaller displacement engine I should get better fuel miliage on the highway out of it compared to a 408W.

Considering that the orignal cars used higher transmission gears me running 400hp/400trq would still put me way over what the orignals had because my gearing is lower as well as having a OD gear (2.20:1 first orignal vs 2.87:1 first) ontop of having lower axle gearing than the orignals (3.08 orignal vs 3.27 - 3.55 for mine)

 

No.. 20% loss is through an automatic, the manuals are much more efficient with losses down around 10%.

 

Thats what I thought but couldnt find specific numbers. Aside from that I am looking at a mild 289-302-351 a 408W is just too much. If I could find a 289 block kit or short block I would go with that and just drop in a cam like I picked thats 2000 - 6000 rpm hyd roller with a lopy idle.

HP I am thinking 400 maybe 450 max. That should be perfect for a 2500lb coupe with 3.27 - 3.55 axle gearing with a TKO600.

I found places offering 289 short blocks or long block kits but the short block is 300 hp and the long block is 350 hp. That might be enough for a every day driver but I want alittle more for track use as well. I see I can get a 347 stroker form Keith rated at 425hp and 415trq for $7,775. I might just go the short block kit which I can get for $2,699 and pick out some good heads and the money I saved going with the 347 over the 408 I can get that EFI stack system. Only thing now is I have to do research again to see what heads to go with cause I am sure 200, 205, 210 cc heads with 2.02"/1.60" to 2.08"/1.60" valve heads are over kill for a 347 but maybe its not.

 

Depends on the powerband you want, big port heads aren't overkill on a 347 if all you're interested in is 5000rpm launches on the 1/4 mile, but on a manually shifted street car I'd rather have balanced HP/TQ curves over a more sane 1000-6000rpm range, so what if that means it only makes ~400hp it will be a fun ride. 180c heads are about the middle of the road for this displacement, smaller ports start to restrict peak HP and larger softens low rpm power, valve size doesn't matter as much as long as the valve/port combo works well together.. meaning delivers good flow numbers. Companies like AFR and TFS seem to have this figured out quite well.

 

Build up a short block like the FRPP 347 crate engine - Boss 302 block, etc. - and run a solid roller cam. AFR 205 heads. Theoretically a 500+hp engine that will wind to 8,000. Sure setting valve lash every 3,000 miles is kind of a pain, but you wouldn't care. That's why God invented two piece valve covers...

 

I was thinking right then. Keith offers his brand of heads which I think are aluminum but their brodix heads modified. The ones I listed is $1600 for a pair and their 195cc ports. Only problem is though I am leaning towards a crate engine kit now. When I did the math I was almost at $11,000 for the 347 stroker short block, the 195cc heads, an aftermarket EFI dist, the A1000 aeromotive fuel pump and A1000-6 injection bypass regulator, the flow kooler hi-vol water pump, the EFI stack manifold with computer, the stack filters, 30 lb/hr high flow injectors and a reproduction Aviaid racing oil pan.

I am thinking maybe I can save money by just going with the 347 street crate engine for $7475 and have him go with the EFI stack system which hopefully if he gets it from his vendor that I showed the photo previously is less than what their 2007 price tag is. They want $3,999 for the manifold alone. This vendor on the forums is selling something simmilar for $3,099 but its an additional $1450 for the fuel/spark computer and another $200 for the stack filters. But a 425hp/430trq street 347 stroker should be good. Its not a street performance one just a plain street one but I could always ask him to swap out the water pump for the flow kooler model and to get a custom grind cam that would give me that lopy idle I want. I love the idle quality of the Big ***** Thumpr cam but I just dont think a 107 LSA would be good for EFI nor efficent. But if he could get a custom ground roller cam to be simmilar then hell I am set. If he can get the engine built with the Stack EFI for under $10,000 I would be set as well. Otherwise I might just have to say forget the stack EFI and go with the Edelbrock Proflo 2 which doesnt look as good but atleast it comes with the fuel pump, the injectors, the computer, and the dist for $3300.



But it is nice though that I finally settled on a engine build and its locked in no going back after reading what I did and with those smaller crank journals that 347stroker should love being wound up to 6,000 rpm and holding her around 3500 - 6000 on a road course shouldnt heat up the oil too much due to the slower bearing surface speed compared to the larger journal 351. And with the 302 I get to run that Aviaid oil pan which is the exact same one used on the coupes back in the 60`s. Just waiting on a email reply from Aviaid if their 289-302 pan will fit a 302 with a 3.4" stroke.



Barron, I was leaning more towards hydraulic since I wanted to drive the car across the country and didnt want something that might need to be adjusted halfways through the trip. But I am going with the 347 stroker though. I might even just tell Keith to build me a 302 rated at 400 hp if he can do it for less than the stroker. I know the 289 crate engines I found with cast iron heads were rated at 300 hp and the aluminum head version was rated at 350hp. I would go with that but the orignals had 380hp and a 302 isnt any different than a 289 so no one could tell if I said its a 289. I have also changed my mind on the power output. I was being insane with 500hp because with that much power I would do nothing but roast the tires, 400hp is about the max for a streeter but 450 could still be used on street tires but would hook up better with racing tires.

 

Alternative C is a 351C/stroker, it's got the small crank journals too.

 

351C wont work. The only engines that will fit is the 289-302-351W. Even the 351W fits on the tight side due to the taller bigger block. These cars have a very low hood on them so you got to be careful with what you use.

Not that good of a photo but you can see what I mean about the hood being low.



But I dont really need alot of power, I came across a chart showing what the orignals had for power and compared it and 500hp is just insane. A guy with a worn out 220hp 302 walked all over another guys car pushing 600 hp just because he didnt have so much power he hooked up better.

I am thinking though 289-302-347 stroker is what I should be looking at. It will provide me with more clearance under the hood as well as providing me with well over enough power for a 2500 lb vehicle.