Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
So it's interesting how you can go from being pretty ignorant on a subject to at least thinking that you're somewhat informed. I've been doing some pretty intensive research on this fuel pump so I thought I'd bring everyone up to speed on what I've found out about the GTO fuel pump. I'm not sure at this point how I missed some of this information initially.
I took some pictures of the disassembled pump which I hope will be enlightening to those who might be interested in this. The first picture is of the bucket. On the left you can see the valve that lets the fuel in the bucket equalize with that inside the tank. On the right where you see the o-ring is the port for the venturi pump. The next picture shows the outside of the bucket. On the left you can see the port that the venturi pulls the fuel through. On the right is the tube/port that the valve in the previous picture is associated with. The next picture is the interesting one in my opinion. The enlarged inset shows the venturi pump assembly which is the black component. You can see that there is an FPR on the assembly. The upper assembly shown in a previous picture is a part of the tank/vapor venting system and has nothing to do with fuel delivery. So the canister I pointed out earlier is not the FPR. I'm taking the long way to tell you that the module is, in fact, a self contained unit. I communicated with a guy who has done two conversions using this pump and he confirmed it. It should be pretty simple to adapt this pump to my tank. This last picture shows the modified module with the updated wiring harness. I still need to fabricate a plate to attach the shortened rods and springs to and weld the assembly to the existing top cover on my tank. Shouldn't be too bad. I want to thank Fred for getting me to think in more detail about what I was about to do and keeping me from making a mistake. I will add more details later. |
DiDueColpi Fred Key West coast - Canada (1386 posts) Registered: 05/14/2010 03:06AM Main British Car: I really thought that I'd be an action figure by now! |
Re: LS4 Into an MGB
That's awesome Scott!
I should have clued in sooner about the FPR. They're using the waste from the FPR to power the venturi pump. Simple, neat and tidy. Looks like you're good to go. Cheers Fred |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6508 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: LS4 Into an MGB
That sounds pretty neat, they're using the return line to fill the bucket from the tank? Like the jet pumps used in water wells use a jet to lift water out of the well? Sounds like somebody was using their noggin.
Jim |
Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Time for a quick update. Well, it's back on the road. A little later than I had hoped before the meet but still earlier than in past years. Also my list of things to do at the beginning of winter was whittled down to about half of what I had hoped to accomplish. Not a huge issue as this is a long term project. I'm still going to rate the car as "rough" but it should be much more reliable now and I'm really happy with where I'm at with it.
So the fuel pump is in and seems to work great! Pressure is right at 58 psi and it's now a true single line system. Here's a picture of it in the tank just before I closed things up. You can see it fits really well. It's really quiet. The car should be much more reliable with this change. I want to say the engine runs better but this is probably like getting a new set of sneakers (tennis shoes) as a kid. I was always convinced I could run faster and jump higher with them. :) This next picture shows where I was coming from for those of you who are wondering "WTF is he doing, the car runs with the current pump!" What you are looking at is a Bosch 040 knock off pump inside a VW Jetta bucket. This is a common performance upgrade for the VW guys. The main reasons I went with it is because it was easy, cheap and the pump flowed enough to support the LS4. I also had a fixture in the bottom of the tank that allowed me to mount the pump bucket by just twisting it on. No fuel tank mods and it got me on the road for last summer. It's kind of "ghetto" and there are quite a few things wrong with it. The main thing is the bucket is just a holder and doesn't function as a surge tank at all. The original VW unit was really nice in that it had a pump housing built into the bottom of the pump that drew fuel from both the bucket and the tank. It just didn't flow enough fuel to use with an LS engine. So I put a brand new idler pulley in my accessory drive and the f&*king thing wobbles. I'm going to replace it before the meet. Seems like it's so difficult to put something to bed once and for all...frustrating at times. It was a plastic one and I'm going with metal now so it will be better all around. Other than cleaning the car up, I'm going to be putting some miles on it and addressing anything that comes up between now and the meet. As I've said many times, I'm really looking forward to it! |
Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Thought I'd do a minor update since it has been a while. I've put well over 1500 miles on the car so far this year. Knock on wood they've been trouble free so far. I had some squeal from my accessory drive but it was the new belts stretching a little and some tightening seems to have cured it.
I took the car on the Eric Jones Memorial Riverrun over the memorial day weekend. It is an all day tour to the Ohio river across some outstanding roads in southeast Ohio. I went by myself so I had an opportunity to beat on my car for many hours and not worry about my wife yelling in my ear to slow down! 😁 Here I am at the start of the day. [crashton.smugmug.com] It was so much fun and it was the first time with the LS. I've been going on this tour on and off since the early 90s so I started off with my 4 cylinder. The torque of this V8 is unreal. I won't bore you with the details but I'm so looking forward to West Virginia next year! I'm in the process of putting the heater back in the car as a summer project . There have been several instances where it would have been nice to have it so it has moved up the list. The good thing is the car doesn't have to be off the road for any extended period to get it done. I've been thinking about doing this for a while and I'm guessing that there is some curiosity about the costs of doing an LS4 conversion into a B. I thought I'd share a little bit of what I encountered. This is LS4 specific. I'm going to present it as a "ready to run engine" with the components I think should be included, you may not agree. Hope this helps when comparing other engines similarly equipped if you want to include an LS4 during the planning part of your project. LS4 w/59k $850 w/Ohio tax Flywheel $400 Starter $70 Starter mount materials $30 DBC throttle body $45 Water pump $100 Accessory drive assembly $200 Total $1695 I don't think that's too bad. Keep in mind that this for an all aluminum LS motor that has 303 HP and 323 ft/lbs of torque out of the box. Also, the LS4 is the red headed step child so it isn't in demand like the RWD car and truck aluminum engines are. There are good and bad things about this. The good is you're likely to find an LS4 that is much cheaper with less miles on it. The bad is you have to deal with the starter. That will be a show stopper for a lot of guys. There is a lot more to this but I'll stop here for now. I know there is a lot more needed beyond what I listed but most of it is going to be common to every engine. This ended up being much longer than I intended. Hope you found it interesting and/or informative. |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6508 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: LS4 Into an MGB
These days that's an exceptional value Scott. And for anyone capable of building their own engine mounts and headers, doing the starter conversion should not be too difficult. We need more info on engine positioning of course but that will come. I'd guess you should have another 200K miles or more left in that engine, how is it doing for fuel economy?
Next year I'd like to consider doing that Memorial Day drive, keep me in mind if you would. Jim |
Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Jim,
I'm getting in the mid-20s so far. I expect it will improve a little when I do the rear axle. I'll for sure keep you informed about Riverrun. Having your car there will shake things up a bit in would imagine. 😊 |
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Re: LS4 Into an MGB
Scott, was there anything preventing you from running a different crank dampener to get around the accessory drive issue? For instance running an ls2 crank dampener/water pump?
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Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Hey Mike,
Good question. I considered just about every scenario I think. When I was first planning the conversion I debated between a truck aluminum LS with the Corvette accessory drive to putting the Corvette crank pulley on the LS4. I haven't gone into many of the goals I laid out when I first started planning this project but the main ones were: o Must fit under the stock hood o Steering rack to remain in stock position o Absolute minimum modification of the car to fit the new engine The first two were show stoppers.....I would have gone a different route to meet those goals, FYI. So when I started looking at the different combinations it became apparent pretty quickly that the truck motor would require a lot more work to fit especially with the size of the sbc bellhousing. The LS4 is for sure the shortest LS engine followed by the Corvette versions. The difference between the two was about 3/4" when using the Corvette pulley. Using the Corvette pulley would have allowed using off the shelf accessory drive components which is a good thing. But as you know, 3/4" is huge and I couldn't move the engine further forward without violating my steering rack goal. So on the downside it would have meant cutting much more deeply into the firewall to accommodate the LS4 bellhousing. It would have made adapting the stock heater assembly pretty much impossible and that was also part of my overall plan. The upside of the LS4 pulley is less intrusion into the firewall. The downside is I would have to design and build a custom accessory drive. So for me it was a pretty easy decision to go with the LS4 pulley. To be honest I was looking forward building the accessory drive and I ended up really enjoying the process......doing stuff like that is one of the reasons I enjoy this hobby so much. I know this is probably much more information than you were looking for but I'm trying to point out it often isn't a simple yes or no choice and this was just one of many decisions I had to make over the course of the project. All of them are a compromise in some way and a good thing about having a plan/goals in place is it is a little easier to assess the consequences of each decision you make. Otherwise it's easy to fall into the 10 year plan as each uninformed decision changes the scope in unintended ways. At least it works that way for me! 😊 Other people are going to have different goals, make different decisions and end up in a completely different place. That's another thing I really like about this hobby.....the great variety you see in other guys work. Hope I answered your question. Scott |
Re: LS4 Into an MGB
Thanks Scott! I enjoyed reading this thread, gave me many ideas for my build. I'm leaning more and more towards the LS4 since it's so cheaply acquired. Mines a 77 RB so might get away with using vette accessories without too much cutting into the firewall.
As much as I hate it I believe my MGB conversion falls into the 10 year plan with 3 young kids at home haha! |
Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Glad you enjoyed it Mike. Don't have kids so I was never faced with that.
My good friend Artie just bought a 78 B V8 and I took a quick measurement of his rack to crossmember gap and it was almost exactly an inch further forward compared to my car. So if you plan on keeping the steering rack in the stock position, which I recommend, your firewall mods will be very similar to mine since your engine will be set back about that much with the Vette pulley in place. Hope you do a build thread here when you get started. I would be very interested in how you approach this. Scott |
MGBV8 Carl Floyd Kingsport, TN (4571 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: LS4 Into an MGB
Quote: Now there's some good info! That is about what I thought. Can't find the thread where we discussed it, though. |
Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Quote: It's here: [forum.britishv8.org] I want to do an update there when i get some time. |
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Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
Hey Jim,
I'm going with an S-10 7.625 3:42. I hope to at least get started on it this winter sometime. We will have to see. I live within driving distance to Moser so that will help. |
MGBV8 Carl Floyd Kingsport, TN (4571 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: LS4 Into an MGB
Found it! Spent nearly 2 hours looking. Never would have guessed it was over a year & a half ago. Google make waaay too much revenue from its not all that great search engine. What a PITA.
Quote: Quote: [www.mgexp.com] Edited 2 time(s). Last edit at 12/28/2016 05:02PM by MGBV8. |
Scott68B Scott Costanzo Columbus, Ohio (565 posts) Registered: 10/25/2007 11:30AM Main British Car: 1968 MGB GM 5.3 LS4 V8 |
Re: LS4 Into an MGB
😊 I remember that thread! Nice you could relocate it. Yeah, time is going by so quickly. As I become more familiar with RBBs I'm more convinced it's going to be relatively easy to fit an LS4 in one.
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BMC Brian Mc Cullough Forest Lake, Minnesota, USA (384 posts) Registered: 10/30/2007 02:27AM Main British Car: 1980 MGB '95 3.4L 'L32' SFI V6, GM V6T5 & 3.42 Limi |
Re: LS4 Into an MGB
Scott,
It's looking good. What does that engine run out of power at? 5500? 6- 6500?? I know what my car is geared like and believe that you might want to look at 3.23 with the extra power even if it does rev higher. Unless you are going with a wide body kit, you're going to need to narrow that axle down. -BMC. Edited 1 time(s). Last edit at 12/26/2016 12:37AM by BMC. |