Can we talk about V8 Miatas/ RX7's again?

In reply to dyintorace:

Your input is valued, and yes you have some inside knowledge.

302 and a t5 seems like the easy button for a budget build. Avoid the 87-89 roller motors as there known for randomly snapping the crank snout off. Thanks too the foxbody being what it is in drag racing circles its not hard to find 302 parts fairly cheap.

If you can find one these days the best starting point for a 302 is the explorer long block. 300 horse is a pretty easy number these days.

SVreX wrote: But I have gotten pretty good at this game, and believe I am ready to hold myself to a higher standard. Most of the quality issues can be addressed with more time and care- except, of course, name brand parts.

You can get away without name brand parts if your fabrication is good and you're not worried about actual resale. And that's just time. Which is the true currency of the Challenge, along with creativity.

The budget is probably a distraction for most people in the context of this thread.

I can build a lot more car for $2K than some people (or than I could have 12 years ago). I am better at budgets than I am at cars (but still capable of a podium finish).

The car I'd like to build is probably what most people would call a $10-15K build. When I am done, I guarantee people will argue with me thinking it is a $20K+ build.

The ideas I am looking for are ones that build quality and perceived value. I will worry about the creative budgeting.

So what makes a build come out with a higher perceived value? You know this already, but it's attention to detail and quality of work. Can you build a bracket for something instead of hogging out a hole and using an undersized bolt? Are the wire lengths appropriate - and are your harnesses bundled and bound instead of strapped with zip ties? Have you paid attention to heat management (cool intake air, very important for the LS engines; keeping heat out of the car and brake/fuel systems)? Does everything work (AC, PS, ABS, etc)? Is the suspension geometry affected by the swap, and how?

In reply to Keith Tanner:

Good list.

Assuming excellent attention to detail throughout, Do you think the motor choice/ platform choice have much effect on perceived value (assuming the choices mentioned in this thread)?

Is Miatalove sufficient to outweigh "RX's are outdated"? Is the LS perceived as a quality choice, while the Ford is viewed as crapcan?

Or do car lovers appreciate both, giving neither a distinct advantage?

LT1s apprently slide right into fc rx7s.

Depends were you are buy lt1s are cheap around here and all the ls stuff is creeping up. Deals can still be found but its alot harder than it was a few yeara ago.

Ls1 ibtakes used to be trash or worth about 30 to 40 bucks now they are over a hundred, and ive seen ls6s in the 5 to 600 range

I am pretty sure that the FC rearend is the same unit as that found in the Miata. The difference is the RX7 have a bolt in upgrade. YOu can bolt in the turbo rearend, axles, and driveshafts to the FC to have a pretty stout rearend.

I have seen broken FC RX7 rearends on stock engine FCs that drift. I have not seen or heard of a turbo rearend breaking.

Budget about 300$ for a complete used Turbo rearend.

wvumtnbkr wrote: I am pretty sure that the FC rearend is the same unit as that found in the Miata. The difference is the RX7 have a bolt in upgrade. YOu can bolt in the turbo rearend, axles, and driveshafts to the FC to have a pretty stout rearend. I have seen broken FC RX7 rearends on stock engine FCs that drift. I have not seen or heard of a turbo rearend breaking. Budget about 300$ for a complete used Turbo rearend.

This project would come with a TII rear installed and a spare.

SVreX wrote: Good list. Assuming excellent attention to detail throughout, Do you think the motor choice/ platform choice have much effect on perceived value (assuming the choices mentioned in this thread)? Is Miatalove sufficient to outweigh "RX's are outdated"? Is the LS perceived as a quality choice, while the Ford is viewed as crapcan? Or do car lovers appreciate both, giving neither a distinct advantage?

I think the RX would appeal to more people than the Miata becasue of the fixed roof, and the lack of "hairdresser" stereotypes.

As for which engine will affect resale, I'd say the 5.0 might have a negative effect, or less of a positive impact. The fact is, they're an older, less efficient design than the LS platform. There's nothing wrong with them really, but at this point, doing a v8 swap and not using an LS (or Modular Ford) seems like the owner left something on the table, unless it's a brand loyalty situation like a classic Ford where an updated engine swap from the same manufacturer probably fits the overall theme better. Talking about mazda's with American v8s though, it's got to be an LS.

In reply to STM317:

Well put.

I'm with STM. The 5.0 is an old engine, the LS is (almost) current. Power levels will be higher, weights will be lower (assuming an aluminum block) with the more modern mill. If you're using an iron block 4.8, though, it's a truck engine. That's going to hurt perceived value for sure.

But there's also the "Mazdas are Ford!" camp. I don't think that's enough of a connection to make up for the older, heavier, weaker engine. But brand loyalty is strong. It's sad.

Im a brand loyalist so the 302/t5 may have been slightly biased but i was also concentrating on the budget part. That and the fact i like old simple things. The ls and its iron truck versions are a good platform if you have zero loyalty to one brand or another.

I'm in the middle of a 5.0/E36 build. The Miata was an appealing chassis option, but I like to track coupes, not convertibles.

I have found it to be a very entertaining project with just the right amount of challenge, if you have the time. It's not really a quick project to knock out.

Everybody says "do the LS" and they're probably right, but 99% of the people who say it to me haven't swapped an LS into anything, and about 90% have never done any kind of motor swap at all, or even owned an older LS motor for that matter. It just seems to be something most people say when they hear the words "motor swap," based on the LS total dominance of the hot rod scene.

If I was starting from scratch I would still do the 5.0, because I'm not a Federal Motors guy. But I won't try to argue it's a better choice.

I don't see any way to get 300 HP at the wheels out of a 5.0 without spending several hundred dollars for aluminum heads. Best dyno-proven 5.0 I have seen using Ford E7 heads did 260 HP with a mild camshaft upgrade, and most guys with GT heads report 20-40 HP gains over the stock 230 at best.

I'm told by somebody I believe that a 5.0 - T5 combo weighs 475 and an aluminum block LS with a T56 is 610 (I believe him because he's done both). That doesn't seem like much of a weight penalty for the LS.

The budget option of re-camming and re-springing an Explorer V8 is truly cheap, but I couldn't actually find one when I went looking (most Explorer buyers passed on the V8). And finding a T5 that hasn't been flogged to the point of death isn't easy either.

A lot of people might say the 5.0 has the advantage for exhaust because there are stock header options that work. Having done the job, I would say it's still not easy.

In reply to JBasham:

Hot rodding scene... Hmmm, you may be onto something I hadn't thought about.

I have 2 '60's vintage hot rods that are both solid candidates for LS swaps. That could be another really good reason for choosing LS- gets me through the learning curve.

And those hp numbers you are talking about aren't high enough. I can get that out of a junkyard turbo Miata. That's not what I am looking for.

JBasham wrote: I'm told by somebody I believe that a 5.0 - T5 combo weighs 475 and an aluminum block LS with a T56 is 610 (I believe him because he's done both). That doesn't seem like much of a weight penalty for the LS.

475lbs for an engine/trans combo is all aluminum 4 cylinder territory. Ford racing lists the packaged weight of a 302 crate engine "long block" without intake/exhaust manifolds or accesories as 528lbs: http://performanceparts.ford.com/part/M-6007-X302E

Even if the packaging is 100lbs, you're looking at 425ish lbs for the long block plus intake manifold, carb/fuel injection stuff, accessories, exhaust, and a transmission.

I looked pretty heavily into just what you are saying last fall, but I was going to buy a kit, not fab myself. From a purely monetary standpoint, 300 hp seems to be the break even of when it was cheaper to go ls + t56. If you are willing to go LS + whatever auto floats your boat, I see no reason to get the older ford.

I would also pay significantly more for a 300 hp 4.8 ls than a 300 hp 5.0 and this seemed to be a common sentiment. With the LS I know I'm at the very bottom of the HP scale and there are tons of good bang for the buck upgrades to net serious ponies, while all the easy (read cheap) ones are gone from the ford.

Also I was VERY surprised that the RX-7's with similar swaps sold for significantly less than the Miata version.

Car craft recently did an article on a 325hp 302 for a grand starting with an explorer 302. Its when you start getting too the 4-500 range N/A that a 302 gets exspensive.

Given that the original question also included several actual scenarios, it really seems like going with the FC/4.8 package you referenced makes the most sense. Everything you need is there, and I know you lean more towards the LS than the 5.0.

In reply to STM317:

That's a Boss 4-mount block and all-forged internals. Back when Ford Racing sold the 302 using a seasoned block (like you find in a Fox), the shipping weight was 425-450 pounds.

But I do think the 475 number is using aluminum heads.

In reply to dropstep:

Well, $1,400 for 325 at the crank with no exhaust system and no accessories. I would still expect 275 on the road, and OP has a 300 minimum.

Didn't they also do basically the same thing another time with nitrous too and get 500HP? For something like an additional $500 in head machine work and $700 nitrous equipment? That's a better budget deal than Denny's all you can eat breakfast bar.

Here's a $1000 400HP 302, including the price of the motor: $1000 400HP 302

It's funny how my thoughts project themselves into a thread almost before I even think them.

I just came from a conversation where I was pondering what V8 I could stuff into a Z3 Roadster a buddy has sitting behind his shop with a blown motor. Before I even run a search ... here is a similar thread on page 1.

Subscribed.

When I built my MG, the original plan was for a 302. Then I saw an LS engine out of the car, and the packaging blew me away.

I dont think there is an advantage to a 5.0 swap if you want over about 280whp.

My buddy made 276whp through a t5 and 8.8 using stock gt40 heads and intake, bolts on and a used F cam. All that stuff is readily available on the used market and cheap. He wants more power now and the cost has gone up a bit, he'd have to start looking at different cams or a custom grind, aftermarket heads and a different intake.

He's to the point even with a set of AFR heads he got for free hes wanting to do an engine swap, says it will cost him too much to make the power he wants and then not have any headroom for later.

With an LS motor (even a 4.8) your close to that stock and probably there with headers and a good tune through a manual, plus you have all the low hanging fruit to gain some quick and cheap power, like 243/799 heads 300-400 dollars, used LS6 cam with GM performance springs (about 100 for cam and 60 for new springs), and you probably bolt on 50 or 60 hp. Friend just made 360 at the wheels with a 6.0 with 243 heads, bolt ons (including a super expensive fast LSX r/t) and an off the shelf TSP cam, through a 4l80e and a 14 bolt. Take the fast off and through a TBSS intake on and he wouldnt lose a ton of hp.

Hell even an LT1 can make 280-300 with barely any mods, mine made 286whp with literally just headers, wasnt even tuned, through a 6sp and 10 bolt.

If you want about 300hp and thats it, I say 5.0 al day long, it can be so cheap (I was given a late model long block, that is in good shape), but if your gonna want anymore than that Id recommend LS, but Id probably go LT1 for obvious reasons.

Keith Tanner wrote: If you're using an iron block 4.8, though, it's a truck engine. That's going to hurt perceived value for sure.

I've been thinking about this...

With old school small blocks the benchmark was the 350. Everybody wanted a 350. But that started as a truck engine.

There were people (like me) who appreciated the 327 for what it was- a 350 with much better revs and top end. The 4.8L is to the 5.3L much like the 327 was to the 350.

I get what you are saying, but a great revving, dyno proven LS is still an LS. There may be some folks who look down their nose on it, but it's still an LS. And all LS stuff can mate to it nicely.