Ok... I finally caved and tossed the x-fire idea.

What do I need to do to a L83 block with AFR220 Heads to get ~500+RWHP?

I do not want to bore it out, but I can stroke it. I do not care if it is carb or FI... though I would perfer FI. And for the hard part... I want to do this cheap, yet make it reliable.

 

have you already bought heads?


..fwiw, 500 rwhp isnt gonna happen cheap.

 

I got the heads... that is why I don't want to change that. I got both with 1.6RR's and springs for 900 shipped... new

I know that it isn't going to be cheap... but I would like to make it as cheap as I can and still have it reliable. I am in no rush to build it and will wait till I find deals on all the parts.

 

Whats your budget?

 

First things first, you need to flow bench the heads you have and see where they are sitting. You got them off E-Bay, did they come with a full flow sheet? Without knowing that you have no idea where you're sitting. From there you can decide the kind of cam that will work with the heads.

You'll need at least a 383 with a VERY nice rotating assembly (no scat or Eagle) if you want to ensure reliability, lots of nice block prep including splayed caps (preferably billet main caps). ARP bolts EVERYWHERE.

Why not build a tried-and-true combo and get 420-440 RWHP. The extra 40-60 RWHP is VERY expensive.

 

I agree with the ARP bolts everywhere. I'd do the scat or eagle forged rotating assembly tho. I also agree I'd do a 425 or so RWHP combo, then, since it's going to be all forged inside, you could spray a 250 shot and be at about 600 RWHP. The rest of the car can't take that tho without alot of money.

The heads you bought are huge for a street car. To make high horsepower they are good, but you need a big cam and either a miniram, hsr, or carb to make the big hp. You will loose streetability some in my opinion, going to be lopey, jerkey, etc. at low rpm. Like I said, good heads for high hp, but it depends what you want to use the car for. If it is street driven alot I'd sell those heads and buy 195 heads. You can still get good hp out of 195's or even 180's, then spray it.

I'm no expert tho, these are just my opinions from searching and what I've found with builds on Ford engines in the past.

 

Im assuming you have a non roller block, so to go roller you have the cost of that; you can make decent power on a F.T. cam but driveability/power under the curve (and now oil issues) is going to be in the toilet in comparison.

Honestly, Dump the heads and get something thats done and call it in with your CC#. I did my build the same way as you and by the time it was togeher it was practically outdated and cost me a whole lot more than it should have. If you want tonot mess with F.I. get a good intake/double pumper and go play.

500rwhp sounds good, but are you going to be able to get it to the ground and use all of it, probably not. At that point what fun is it unless your in 3rd+ gear or at the track.

Dont think anyone here is trying to dscourage you, just trying to save ya major headache and $$ in the long run


Edit: Youre going to have to bore/hone it so you have the right clearance for new pistons.

 

I would never use SCAT or Eagle in a car that I was planning on 500+RWHP. Maybe that's just me but I've heard some bad results from others. Go with Lunati, Crower, Oliver...etc.

A 220cc head is not too large for a street engine, if built correctly. My heads are over 220 cc (closer to 228) and my car is a daily driver. But the head work cost me over $3000 to get them there, and that's just the machine work and parts...not the actual heads themselves. I've said this a 100 times before, it can be done a LOT cheaper now...but mine were done over 3 years ago now.

Those heads will want to rev to make power, and the higher the RPM's go the more money that needs to be spent for reliability.

 

Basically, what I'm trying to say is there is no such thing as a "cheap and reliable" 500+ RWHP C4.

 

Frankly I don't like it when people give advice on what they have heard from other people. We see a lot of 360 sprint car engines built with eagle and scat parts; sure a 410 won't run them but the 360's make 600 hp or so and run for a long time between freshening. If you want to make big power it's pretty simple. Give it some compression, some cubic inches, and some cam. With your heads you will be able to get enough RPM out of the combo to get that kind of hp. I'm not dissing anyone but I really don't like anything other than first hand, builder experience. Too many times the drivers and crews don't know what's going on with the engines they buy...

 

A race engine is a completely different animal that a street engine. And they will NOT be putting the hours on them that a street engine will.

And this isn't a "heard from a person that heard from a person"...these are people that I see at car shows every weekend. When I don't see a person for a few weeks, then ask them why and get "threw a rod at the strip" or "my engine destroyed itself".

 

Doesn't matter... just trying to keep the prices down.
I may settle for that. However I would like to keep it a 377.
This will not be a street car. I will be using it on road courses and the occasional drag trip. I know you can't really have one engine do amazing at both due to the rpm range desired for both. So I would rather have it more for road tracks.
It will be tracked... not street driven. and I am not using new pistons. The stock L83 pistons and rods are forged from the factory... that is one of the reasons I am trying to keep it a 377 so I don't have to spend a few hundred more on pistons and rods.

 

For something you wanna make 500rwhp for, those parts are shrapnel in the making, dont do it.

I can appreciate the concept, but you cannot do a motor like this and skimp anywhere. Youll need premium parts and machine work throughout for it to last. Sorry, theres no way around it.

A quality motor making that kind of power with all the right stuff in it will easily run you over 10k. A "crate" motor isnt going to cut it. Can you get one screwed together cheaper, probably but because it goes together and runs doesnt mean it will last; doing things twice sucks. Honestly a 377 (destroked 400) would be the ticket however then you run into the cost of an aftermarket block for reliability.

JMO, others may differ.

 

Back up just a second... With a longer stroke crank you aren't going to be able to physically "re-use" the original pistons. The pin height is going to be wrong, therefore the Deck height, etc. You Might be able to get away with making the stock rods fit, but at the power level and rpm's you are talking about all they will be is heartbreak (and shrapnel).

Besides, a 5.7" rod length isn't what you really want for what you are trying to do anyhow..

The bottom end of the motor (rotating assembly and block) doesn't actually Make horsepower, but it has to be able to Withstand the torque and rpm - wrong place to skimp on good parts.

 

I agree with most all of the above. The factory forged pistons and rods are good to throw a set of high flow heads and a moderate cam and a nice intake/carb or a miniram on and run the hell out of it for a while, maybe even spray a 150 or 200 shot. It would most likely last quite a while on the street and be at or near 400rwhp n/a. But if you are going for 500hp and track use, you need huge heads (which you have) a huge cam, high compression, etc. that I don't think the factory forged pistons/rods can handle. I'd love to have those pistons for my car, but I'm shooting for 375rwhp and a 150 shot someday. For now I'm shooting for 325 to 350 rwhp and a 100 shot, until I can get a forged bottom end. Point is, the above posts are right. Build what you can afford, and since your car is not a street car you have the right heads, but you basically need to take your block and start from scratch. Nothing in it is built for 500rwhp, and not only that the track use will put that 500 to use all the time whereas a street car will only be hitting full potential once in a while. I hate to see you save $500 only for it to come apart and ruin the heads, cam, and everything else you purchased new. If you have the budget go all out, build an 18 degree or even 15 degree engine. Also.....and I might get hammered for saying this....... if I were building a 500rwhp n/a track only car it would be carb all the way.

 

Rons85 got it ...stock rods & pistons aren't gonna work with a 3.75 crank. Also, I was thinking the AFR 220 need offset or shaft rockers, but I could be wrong here. And the heads are just too big for your CI anyway IMHO.

 

Just go 383 and be done with it. Doesnt cost that much and a machine shop can bore it for cheap too. Otherwise you might as well keep it a 350 and use some expensive bolt ons like a cam, your heads, a good intake, and a good carb for FI (carb will be a LOT cheaper). Then spray it and you should be able to make 400 rwhp, maybe more if you dare.

 

that is something else I was considering... what carb setup should I use for ~400hp out of a 350? If I do that all I need is cam, crank, and intake setup...

 

You need about $15K for a crate engine and a beefed up drive line.

 

When you bought the crossfire, did you plan on all these mods?