Engine and Transmission Tech

This subject may have been beaten to death but I have not seen a head to head combat of the two camps. If it is post elsewhere, please let me know.


I am partial to the 3.4L V6 and find that my total car had to be upgraded to make the most of that engine as-is. As is, for street purpose, my almost standard suspension works well but for autocross, the car could use a little more suspension tweaks. If installing all the suspension upgrades and spend another $3-8,000 on the underside of the car- beyond what is already there, at that point when the car is already turning in some extremely fast times, a person could go a few tenths of a second quicker with a large engine. Mind you this is all theory and my car is not being moved from the 3.4L as it is VERY quick, I have always wondered why so many stop at a 302 if going for more power. I can't believe the end results are that much lower priced, just easier to find. I have also read the LSx can be as nearly heavy as the 302. Is there anyone out there with this experience?

Having worked with other conversions and engines, I have asked myself which I would do if I had to "keep up with the Joneses"- a Ford 302 or one of the various GM LS series engines.

Ford motor:

PROS
Available for many years and readily available
Starts with good power
Pulleys from "Exploder" make it short
Intake Manifolds from certain Mustangs make it shallow/ fit the MGB supposedly
Headers and install kit readily available
Slightly (Correction Requested!!) smaller than the LSx engine
Aftermarket parts available to bore and stroke out to about 5.7L


CONS
Heavy- needs alloy heads to get the weight down
Cylinder head mods costly
Need to get parts from multiple engines in order to fit decently
Probably need more parts car types to get a system to fit than the LSx engine
Requires firewall mods
Requires subframe mods


Ford manual/auto choices:

AUTO
-AOD
-Other

MANUAL
-T5
-T45
-T56 6 speed- I believe?




___________

GM LSx motor:

PROS
Light- no need for weight reduction items
Available for many (newer) years (than Ford) and readily available (but not as much as the Ford 302)
Starts with better power than Ford engines
Pulleys from multiple OEM car sources- (uncertain which is short and gives a good front timing chain cover configuration)
Intake Manifolds from certain vehicles make it shallow/ fit the MGB
Headers and install kit readily available
Slightly (Correction Requested!!) larger than the LSx engine
Aftermarket parts available to bore and stroke out larger
Two engines to consider 5.7L LS1 and the FWD 5.3L LS4

CONS
A little more up front on the 'barrelhead'
Truck engines are iron block- not worth getting into if the weight was the reason to avoid the Ford 302
Need to get parts from multiple engines in order to fit decently? (Correct?)
Requires firewall mod, more than the 302 (Correct?)
Requires subframe mods, more than the 302 (Correct?)

I haven't said keep the original heater in place (and steering rack) and still have a 50/50 weight distribution but that is another item that needs to be discussed.

GM manual/auto choices:

AUTO
-4L60
-4L60-E
-700R4
-Other

MANUAL
-T5
-T56 6 speed (large- but can fit)


Please let me know why you chose the engine you did and what you found the pluses and minuses were on either.

Hi Brian
my name is Bill my MGB is a early 74 (chrome bumper) I wanted a small block chevy just because I am a chevy man, I was telling my brother and he said he had a 2001 Silverado he wanted to scrap but he gave me the 4.8 because he just wanted to see if I could get it in and make it work well 2yrs later bingo and I love this car more everyday. as far as the cutting of the firewall from what I have read no more cutting than a ford I got rid of the efi in favor of the carburetor glad I did, but had to go with a hood scoop the weight difference is definitely small she handles great I wanted a mini hot rod look so I raised up the front and rear by 2 inches I put a spacer between the cross member and the body in the rear I added 2 leafs to a set of new springs and made new shackles 2 inches longer so I got the stance I wanted and didn't have to cut the cross member for the oil pan as far as the handling I put 195 65 r 15 in front and 215 60 r 15 in rear also traction bars in the rear so she really sticks to the road I put a piece of square tubing from the front leaf spring mount to the center cross member for reinforcement but found out later that I didn't need it but I left them. the tranny is a turbo 350 I am getting 17-20 miles to the gallon some day I will get a 700r but now this really works I did have to raise the tunnel by one inch and hammer a little bit on each side I put a hurst promatic shifter with a cable works great well I love this car 0-60 4.9 sec around 300 horses plan on recamming her and bumping up the hp by about 75 with what I want to do good luck with your build keep us informed

Brian, I think it's more a matter of timing than anything else. Ford 302's were/are readily available and very reasonably priced long before LSx motors fit those criteria. So, while similarly sized, a few folks started making parts to make installing the 302 easier. Steve Carrick came up with and started doing headers, then Ted Lathrop started adding the motor mount option on his IFS. Later Pete Mantel and Bill Guzman started doing more complete kits.

To date, no one has done a similar kit for LSx motors. So, at least as far as I know, folks are on their own with motor mounts, headers, and any cross member modifications. I wouldn't hesitate doing those now, but i know when i started my project that stuff intimidated me. I'm sure it does others. So, as soon as someone does a kit, you'll probably see the LSx motors become as or more prevalent than Rovers or 302's.

It's been an interesting progression. Back in the 70's there were a few (very few) rumors of a factory V8 MGB using the Buick 215 but nobody knew anything about them. There actually were a couple of very early conversions in the country that had used the 215 and the SBF but they really didn't come to light until the last few years. In reality, the SBF conversion has about as old of a history as the 215, and the SBC wasn't that far behind, though it was (mistakenly) believed to be too heavy for the car. So these swaps go back to the early 70's and in the case of the 215 and SBF clear back to the early 60's. That's 50 years of MGB conversions now and this year marks a significant milestone.

A little less than 20 years back the V6 conversion began to make it's way in and met many differing views, but it filled a blank between the BOPR and the original engine and enough owners felt they wanted to be in that area between a spirited sports car and a muscle car than it succeeded well. And it has gotten much better. The SBC eventually gave way to the LS which rapidly became all the rage in custom cars of every type. If you managed to make any of the venues of the recent Hot Rod Power Tours you quickly get the impression that the LS has taken over the entire planet, and admittedly the reputation of the new kid on the block seems to be justified, as from all appearances it is an exceptional powerplant.

Which brings us to the bleeding edge of production engine development, the successor to the LS, the New LT1 with direct injection. And during all this time the SBF has been updated and modernized and can still be purchased outright from the OEM. The BOPR/SBB meanwhile has become an orphan, as have all the commonly used V6 engines, the ubiquitous V6-60, the Buick V6, as well as the lesser known Ford variety. How long the SBF will continue is an open question, as there seem to be no plans at Ford to continue with a pushrod engine of a newer design. But the dividing line between an older and a newer series of engine should properly be placed not at a usually arbitrary production start/end date, but rather at the date where advanced technology demands a redesign of such magnitude that the old cannot be easily reconfigured into the new. In truth, although a great number and variety of incremental advances have occurred in pushrod engine design over the past 60 years and more, the improvement of direct injection is the one single advance that is not capable of being retrofitted to the earlier engines without major design changes, and in this regard relegates all of the earlier designs to a common category. Regardless of the variations in things like roller cams, improved main seals, electronic ignitions, port injection and such, any or all of these improvements can be applied to virtually any pushrod engine built during that period, and as such they are all very similar. What is the major difference between the SBF and the LS? First, displacement, secondly an alloy block. But in terms of weight, about the same, with the advancements giving the LS greater block strength. The advantage of using the older technology when a new design comes on stage is always cost, and nothing more. So if you are cost conscious, and who of us isn't, then your choice between the 302 and the LS has to be based on your overall horsepower goals, or on your manufacturer's preference. A preference for the BOPR/SBB has to be based on perceptions of originality and/or weight considerations. A preference for V6s has to be based on economy concerns or a preference for the exhaust note of a six. Little else makes sense when dealing with an older technology.

As for the emerging technology, it is mostly a question of cost versus benefits. The new engine is going to be expensive, both to acquire and to install. But it will be cheaper to operate as well as more powerful.

[www.greencarcongress.com]

[gasoline-electriccars.com]

But as a production engine the cost should be within reach, though perhaps not during the first year's production. It can be expected that GM will make this engine and a suitable control system available to the performance industry in the hopes that it will catch on like the LS did, so at this stage of the game one would have to consider it as a viable option when planning a future MGB conversion. The question then becomes, is the benefit enough to justify the cost? Obviously that would be a very individual question and we have seen where this question would definitely have a positive answer in some of our more top end conversions. I think there is no question at all that in a car such as Terry's or Dan's GTs this engine choice would be easily justified. Or in a car such as the MG-Roadmaster. And there are quite a few more builds in this range of quality where this choice would be a simple one. But where would the dividing line fall? In all probability it comes down to actual cash outlay and installation complexity in terms of the control system. But we are certainly going to see this swap, the only question is who is going to be the first to do it.

Jim

I haven't owned or built either a 302 or an LSx, and I don't feel qualified to discuss their differences in detail, but my first impression is that the LSx engines have huge advantages over 302 engines in terms of their factory EFI and electronic ignition systems. Am I wrong? Enlighten me.

I like the way Chevy intake runners wrap across the vee, nice and low, and very cool looking... now if only Chevy hadn't screwed up and pointed their throttle bodies the wrong direction! (But they're reversible, aren't they? Surely someone must be doing cowl injection. No?) On the other hand, 302 EFI hardware sits so very high. Having the throttle body aimed to the side means you'll need an elbow right in front of it. No one can tell me that's one of Ford's better ideas. Based on Calvin's tech session on programming his LS1 EFI system... it appears to be a very similar process to what I'm familiar with from setting up MegaSquirt. Are the 302 systems that straightforward to tune? Jim may be right that direct injection is the future, but I think it's far clearer that carburetors are already obsolete for new builds. Therefore, the comparative merits of EFI systems are an important topic. Anyone care to discuss them?

" BOPR/SBB is an orphan", really ? 3 manufactures of aftermarket heads, new/improved blocks from Cosworth/coscast. I don't belive the rest of the world, has quite given up, on the RV8-just yet. The SBB crowd, could have been using TA heads, from day one, but either denied or ignored. Long live the Rover ! Onward, roverman.

An orphan in the sense that it is no longer in production by a major manufacturer Art. Everything you say is true, and the Rover will be around for quite some time yet, and performance parts are plentiful, but it's production run is over. In every sense it is the SBC of the European (and some would say World) market, but that doesn't change the fact that it has been replaced.

Jim

I keep wishin/hopin, some savy group of aftermarket types, will perfect direct injection, inclusive of the spark plug,(same hole). This could be big, for retrofits of pre D.I. engines. Cheers, roverman.

I think its fairly easy to modify and tune a fuel injected ford 5.0, but Curtis is definitely right that the manifold height is a major disadvantage. The 94-95 mustang intake fits under a chrome bumper hood (at least it did with the mounts I made), but it's the worst performing ford 5.0 efi intake that is available. If I started over (and who knows? Maybe I will) I'd do a budget LS with the iron block 4.8 or 5.3 and mate it to a t5 or MA5.

I wish I had the skill and equipment to make a custom efi intake for my 5.0 that was low and had a front throttle body (like the LS).

I don't know why people don't just throw away the top manifold and make a top box like Curtis did on his 215. Sort of like the GM performance RamJet system in this link. You could do the throttle body the other way for cowl induction also.

[www.carcraft.com]

Quote:

On the other hand, 302 EFI hardware sits so very high

There's no law that says you have to use the factory EFI. I didn't, I used an Edlebrock unit and got by without a bulge in the hood (with a custom air cleaner). There's also no law that says you have to use EFI at all. The rumors of the death of carburetors are greatly exaggerated. I just received the current issue of the JEGS catalog and they devote a full six pages to carburetors. I didn't count the pages devoted to carburetor intake manifolds.

This is my attempt to lower the overall height of my Ford. The baseplate is 1/2" alum that has been radiuses onto the lower manifold ports with a 1/2" radius. The plenum is essentially open with aluminum tubes used for crush strength. The lower manifold is an original '97 Explorer round passage type.
Dennis

According to an article in Hot Rod magazine [www.hotrod.com] the aluminum LS1 block weighs 116 pounds. By my own measurement, the Ford 302 iron block weighs 127 - only 11 pounds more. Not nearly as much difference as I would have expected. Since they both use aluminum front dress, heads, and intake, I would assume that 11 pounds would account for most of the weight difference between the two, meaning that the LS1 is not much lighter than the Ford at all. Not really enough to worry about.

Dan, You are right. The LS motors use a lot more aluminum thickness for strength where necessary. Plus they have more width and height than the Ford. Your fuel injection setup is the lowest profile. The LS4 that Scott is doing is the shortest overall length.

Thinking along the lines of an "it's already built" concept and trying to keep from having to do a bunch of work, I am tryig to determine which is MORE plug-and-play with the addition of what will end up costing more (with the false thought that both have the headers/mounts available= wrong but skip that point)




Going off my understanding, please correct me, but the LS series is somehow dimensionally larger?

If so- which direction?


The weakest LS engine still produces more than a strong 302 that was a factory built engine- not including crate engines with need to purchase intake, pulleys and everything else.


Also, the 302 would be an engine that, I would think, alloy heads are a good idea for handling and more power to get the engine up to LSx power levels.

I just want to get a handle on the best points of both engines for the MGB.

-BMC.

Quote:

I like the way Chevy intake runners wrap across the vee, nice and low, and very cool looking... now if only Chevy hadn't screwed up and pointed their throttle bodies the wrong direction! (But they're reversible, aren't they? Surely someone must be doing cowl injection. No?)

Sorry for the delay on this Curtis. I knew I had bookmarked this somewhere.



The rest of pictures can be found below:

[www471.pair.com]

That's very cool!

I built one a while back with a 4A-GZE and an Alfa transaxle that was crazy fast.
That LS version must be insane!
I want one bad.
Cheers
Fred

Quote:

Thinking along the lines of an "it's already built" concept and trying to keep from having to do a bunch of work, I am tryig to determine which is MORE plug-and-play with the addition of what will end up costing more (with the false thought that both have the headers/mounts available= wrong but skip that point)

Brian,

At the last meet, Pete Mantell mentioned that he has an LS kit under development....not sure of a timeline. FYI

Good to hear. Variety is the spice of life.

Is the width of the LSx wider than that of the 302? Less room between frame rails?

-BMC.