MrSteveOh

I have just purchased an 02 and I plan on putting a V8 in it with the help of my son. We are trying to figure out the best V8 to use. I have visited monstermiata.com and flyinmiata.com to try and compare the Ford and Chevy engines. I'm still it sure which one to use. I am very open to suggestions.
My son just mentioned that the new Mustang Boss 302 would be a great engine, but I haven't researched to know if it will fit. Again, any suggestions would be appreciated. I know everyone has their own favorite and I am looking for multiple inputs to help me make my decision.

Al English

Overhead cam V-8 engines tend to be wide, and heavier than a comparable pushrod engine. Measure the Boss engine, but I suspect you will find there wouldn't be enough room for exhaust with the engine installed where it should be. In some cars a little extra weight isn't that big a deal. In a 2,200 pound Miata 100 pounds is nearly a 5% increase in weight.

If you don't want to do everything yourself I believe your only do-it-yourself options are a Ford smallblock or a GM LS. Neither is bad. I have nothing against the Ford, but the LS engine is lighter, and it offers more performance per dollar. One down side is that a 350HP+ LS is pushing the limits of the T-5 trans normally used with the Ford. LS swappers address that by using a bigger and heavier trans. A lighter but expensive alternative is an aftermarket G-Force T-5 with stronger gears, stronger mainshaft, and stronger case.

In spite of my preference for the LS, I am doing a Rover swap. To achieve the power to weight ratio of a healthy LS the Rover engine needs a fair amount of upgrading and modification, and a considerable amount of weight has been removed from my car. My car will have performance comparable to an LS swap, but the car will be lighter. On the other hand, most wouldn't be willing to strip their car to the point I have. I guess the bottom line on what I'm doing is that it's definitely not the path of least resistance, or the most performance per dollar.

Carlisle

I have studied this question before building my 2001. I have a close friend that has the 5.0L ford, stroked to 347cu.in and I went the way of a 6.0L LS motor. The kind of HP an LS motor can put out is so high that it only depends on the $$ your willing to spend to get what you want out of it. The LS blots up to the great T-56 trans that is really strong and gives you a chance to put some gears in the rear and still drive (in 6th) at a low rpm on the road. Stroke a 6.0 or 6.2 and get big displacement #, the engine fits under the hood well without alot of hassle. Also there is the Boss Frog kit for the LS motor and I used it because I liked the boxed subframe they make and I went with strength throughout the build. Used an 8.8 Ford rear with stage 2 axles and a complete LS7 clutch setup. I've raced it on the stripe and on the road course and it hauls and handles either way.
Good Luck in your build and mark everything and keep everything until your completely done (pictures are great) so you won't want something you threw out earlier.

Al English

The same is true of the SB Ford. Aluminum block and heads help with weight. With the right parts it's possible to get 600+ reliable naturally aspirated horsepower. The difference is that you can get more horsepower, from a lighter engine, for less money, with an LS. But if we are talking about an all-out, expense is no object comparison, the differences between the two engines become fairly small. When both engines need an aftermarket block, aftermarket heads, aftermarket crank, aftermarket rods, premium valves, replacement intaqke manifold, etc, etc, you are using a minimum of the original high value stock parts.

MRM331

The less money thing is up for debate. When you factor in the cost of the T56 vs a T5 the LSx becomes a bit more pricey. The assumed low weight of the LSx is a bit deceptive as well. First, the engine does not weigh that much less than a 5.0 with aluminum heads. Second, the afore-mentioned T56 greatly outweighs the T5.

-Jason

Al English

Stock weights for 302 vs LS are about 50+ for the Ford. Yes, a set of aluminum heads would help. Those cost around $1,500 and up. If I remember correctly the difference in trans weights is a little over 25+ pounds. So total, a stock Ford is about 75+ pounds, and, less power. An all aluminum SB Ford would probably weigh a little less than an LS and built with the right parts the potential is very high. Unfortunately that's an expensive option.

A simple adapter lets you put a Ford(the strongest version) T-5 on the back of an LS engine. The reason people generally don't do that is because the output of most of the LS engines exceeds the working capacity of a T-5. If you increase the power of the Ford to match an LS you encounter the same trans limitation. A G-Force T-5 would be lighter than a T-56, and would be more than adequate, but that's an expensive alternative to a good used T-56.

If cost is not a consideration there is a world of good options. If cost is a factor, in most respects the LS wins.

fmowry

I'll chime in way late to this thread. Both motors are great and the results will be great. The biggest reason to go with the LS is if this car will ever move to a state that has OBDII emission requirements. Many states require functioning OBDII for cars newer than '94. It is also a common requirement to have a motor of the same age or newer when doing a swap.

Those are things to consider.

werTurner

This is all very new to me and this article really opened my eyes.Thanks for sharing with us your wisdom.I recently came across your article and have been reading along. I want to express my admiration of your writing skill and ability to make readers read from the beginning to the end. I would like to read newer posts and to share my thoughts with you.



Karen Millen Outlet
Moncler Jackets Outlet
North Face Jackets Outlet

sixteenpushrods

Clearance becomes a factor as well. Don't forget that. The LS engines require moving the sway bar forward (bad) or cutting the firewall. Either motor has issues with hood clearance but with the right intake, they're both doable. The biggest benefit to the LS is the technology employed in it to save weight. That said, the overall dimensions of the Ford motor being smaller, it weighs about the same (if not less) as the larger LS motor when dressed with a light aluminum intake and heads. You'll have a boadload of money to spend on upgrades with the Ford that you have to spend to get a GM core. Since they sell so few F body cars and they're almost entirely automatics, they are scarce for cores so the price is high. You can get a junkyard 5.0 from an Explorer for nearly nothing and it's a decent motor to start with.
All out, it's a toss up. Either motor is very capable of the max hp that comfortably fits the Miata chassis. Spending the same money, getting about the same power and the Ford is easier to fit because it's smaller.

miatainthe10s

Im yanking a 375 rwhp ford 347 out for an ls based engine. Long run you will be happier with the ls. Besides the obd2 factor. The factory pcms are flashable via hp tuners or efi live.....

charchri4

Seems to me the bottom line issue is still the headers. Be it Ford or Chevy who cares if you have 400+ hp capability if the engine is choked out.

Anyone know what Martins headers max out at?

flydoug

I am new to this site and saw the Gearz show on the Miata Banchee and got excited. Can I get some advise?

charchri4

Welcome! Yeah I love that Gearz series and have watched the conversion episodes many times.

I would suggest you just start reading on this forum. There is a wealth of information out there. A great place to start is to read any post from MRM331. His name is Jason McCully and he has converted 4 miatas and not only is a really nice guy but he knows his stuff. BIG TIME! Start here:

McCully Racing Motors- Our Builds...we're doing our part to help empowering Miatas one car at a time...

Other places to go are:
Home -
Flyin' Miata : V8 conversions : Turnkeys and tradeins

Once you spend the next 20 hours reading check back with specific questions and there is lots of folks here that will help you.

LCarpenter

I have a LS1 in a 91 and am very happy with everything

Qvox

lol

Apparently, Geerz is really stirring the pot for Miata conversions. This is my first post, and yeah, I'm here because of the Banshee.

I haven't been able to get it out of my mind. Light car, American muscle ...I've always wanted a Shelby Cobra, and this seems like it just might fill the bill.

Sorry to pipe in without adding anything to the thread. I'm still learning, and thought I'd use the opportunity to say HELLO!

Carlisle

There are a few question you should ask yourself.
What is my budget?
Is this for racing or street pleasure?
Is it to be the street sleeper?
Do I want the fastest thing I can put together?
Track or Strip?
The Ford route is less expensive with used parts everywhere.
The LS route is for LS1 or LS3 super power available.
I spent more than many some as I wanted a modern reliable highout put motor that
gave me good mileage and a fast car.
Good luck
10,000 or 35,000 buck will do it.
Steve

charchri4

For sure and whatever number you think it will cost before you start be prepared to add at least 30% to it.

I wonder what ever happened to the guy that started this thread since he has not been on the forum in over a year.

tbone heller

[QUOTE=charchri4;5941]For sure and whatever number you think it will cost before you start be prepared to add at least 30% to it.

In reality, you should DOUBLE IT. LOL!!

Vettedrmr

Welcome to the nuthouse!

1. There's no such thing as a cheap build
2. If you don't enjoy the satisfaction of solving fairly tough problems, don't do this. If you do, then you'll probably find the electrical systems to be the most tedious. Minor welding for the V8R setback conversion is no big deal.
3. If you can, buy a donor car for either your SBF or LS drivetrain. I bought a totaled '00 Camaro SS, saved me a HUGE amount of time and money on all the small tidbits.
4. Read, Read, READ!!! Lots of great threads, both SBF and LSx setups, both here and on the "other" forum.
5. Pick the engine you have a passion for. There are few engines that sound as good as a SBF with a good dual exhaust, but you have to deal with limitations on what Miatas they can go into in some states. LSx engines, being current, are easier to pull a given amount of power out of, although as several have said here, both are great platforms.

Did I mention to read up?

HTH, and have a good one,
Mike

charchri4

+1 to what he ^ said. That's all the advice you will ever need!

Qvox

Very wise words.

I can't imagine anything being more tedious then sorting out the 21 year old vacuum system of 560SL. It'll make you lose your religion. But then that is half the fun. Making things work.