MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

Go to Thread: PreviousNext
Go to: Forum ListMessage ListNew TopicLog In
Goto Page: PreviousFirst...7891011121314151617...LastNext
Current Page: 12 of 22


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5379 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: LS4 Into an MGB
Posted by: BlownMGB-V8
Date: December 15, 2014 09:38PM

Interesting, plus you can buy the blank material.

Jim


kstevusa
kelly stevenson
Southern Middle Tennessee
(820 posts)

Registered:
10/25/2007 09:37AM

Main British Car:
2003 Jaguar XK8 Coupe 4.2L DOHC/ VVT / 6sp. AT

authors avatar
Re: LS4 Into an MGB
Posted by: kstevusa
Date: December 16, 2014 07:16AM

Maybe i missed something, but doesn't anyone have their flange surface trued once they finish welding up thier headers? If headers are puurchased in the A/M, they can still be trued. We used the Old Cyl Head machine; One side required quite a bit to be removed to achieve a flat surface.


theonlyiceman53
Bill Russell
Florda
(80 posts)

Registered:
11/18/2008 06:01AM

Main British Car:
77MGB 350 Chevy with LT1 heads

authors avatar
Re: LS4 Into an MGB
Posted by: theonlyiceman53
Date: December 16, 2014 06:09PM

Hey Kelly,
I build mine with the flange bolted to a spare cylinder head and haven't had any problems with sealing. I always figured I would straightedge it and use a flapper wheel to true it up if I had to. Don't even want to think about clamping it down in my mill!
Cheers,
Bill


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 16, 2014 08:25PM

That's a good thought Kelly. I'll put a straight edge on it to check it. I'm betting the header itself is hanging up on something and I just didn't notice it. I haven't had a chance to look at it yet. I did that video at the end of the day and it wasn't apparent until then how bad it was. I'll get it off the engine first thing Saturday and take a closer look at it. I'm pretty sure I'm going to take Jim's advice on those manifold gaskets. They look like they will handle small imperfections really well.

So I've run the motor probably no more than 5 minutes total time and it's sounding better each time I start it. The audio recording isn't really capturing how it sounds but it is running smoothly with no obvious bad noises. Oil pressure is at 50 lbs. at idle. You never know with a junkyard engine. There was a date of October 2010 on the oil filter that was on the motor when I got it and the tiny bit of oil on the tip of the dipstick was really clean so I imagine that the car it came in was totaled not too far from that date and the engine has been sitting since. My cheap Chinese OBD2 cable gave out at the perfect time so I was unable to check for codes or take a log unfortunately. So I ordered another cheap Chinese cable to replace it. :)

I had a bit of an adventure as I was troubleshooting the no start condition. The first thing I checked were the grounds and couldn't see any issues there. I actually added another ground from the head to the body while I was at it. Next I checked the ignition wiring to make sure they were grounded and that the PCM control wires matched up to the correct cylinders. Same with the injector wiring. All was good there. I checked the voltage drop at the battery and was surprised that it was in the mid 8 volts while cranking. While trying to figure that out I noticed the ground cable eye that bolts to the body was cracked and the cable was hanging on by a thread...not good. So I replaced that with a much thicker cable and cleaned up the terminals and clamps while I was at it. That helped a whole lot. It got me to the low 11- high 10 volt range. The funny thing about it is the engine was turning over like it was a warm spring day the whole time. Anyway, I've got a battery kill switch I'm going to install and I'm going to run a cable to ground things at the transmission when I install it and that should make things even better. After all that, still no start. The next thing to check was the crankshaft position sensor which is behind the starter so that had to come off. Sure enough, two of the wires were crossed. I could have sworn I checked those. Funny thing is it was correct for the 4.3 V6 in the S-10 the harness came out of but not for the 0411 LS V8 motors. I spent time while I had things apart fixing a pesky fuel leak caused by a careless flare I did and tidying up the wiring that runs down the fender well. All things considered, all the troubleshooting was a good exercise and will result in a more reliable car in the end....all good.

The next few tasks are the throttle cable/pedal, which is in process now. Then then tweaking the transmission tunnel for the shifter...the engine is shifted back about an inch and a half from where the previous V6 motor sat. Then the fuel pump and a bunch of other small things like permanently mounting the PCM, putting the interior back together and adding the kill switch and the cable to the transmission. The largest fabrication task that is left will be the accessory mounts/brackets at the front of the motor. I've located a machine shop to handle one of the smaller tasks that I can't do myself. I'll give much more information about it as I get into it. I must be forgetting something but overall I'm closing in on it!

Gosh, as I'm proof reading this I realize I just wrote a book!


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5379 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: LS4 Into an MGB
Posted by: BlownMGB-V8
Date: December 17, 2014 11:04AM

Switched sensor leads is a common issue if using a VR sensor. Your voltage drop can be a real issue with an EFI system. Not unusual to have a motor that will crank OK but not have enough voltage to fire off. I'm not sure whether this is an issue with the coils (I suspect), the injectors, the ECM or the crank sensor.

Jim


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 17, 2014 06:09PM

Jim,
From what I'm reading, when you get to around 10 volts you start having difficulty firing the coils. The injectors seem to "fire" with a 9 volt battery so they may be more forgiving. A crank sensor signal is required for a start so I had a couple of issues going on. I'm anxious to see what it does once it gets into closed loop which won't happen until the cooling system is in place. Lots of details which is part of the fun.


74ls1tr6
Calvin Grannis
Elk Grove,CA
(1112 posts)

Registered:
11/10/2007 10:05AM

Main British Car:
74 TR6 / 71 MGB GT TR6/Ls1 71 MGB GT/Ls1

authors avatar
Re: LS4 Into an MGB
Posted by: 74ls1tr6
Date: December 17, 2014 08:56PM

Scott, At minimum get your exhaust leaks taken care of between heads and 02 sensors. Its not as bad behind the 02 sensors to get it on the road, and get all the other stuff dialed in with the swap. That way your computer can do its job to keep it running smooth and idle right. Are you running a vss (vehicle speed sensor) sensor on your transmission? That can change idle once the cars starts to roll. Just some thoughts I went through.



Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 18, 2014 07:42AM

More good advice, thanks Calvin! Yes, I wouldn't even think about not using a VSS. I'm doing a home brewed one off the differential flange. Mounting it is one of those many small tasks that need to be done yet. I'll post some details about it when I get to it.


mgb260
Jim Nichols
Sequim,WA
(1831 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: LS4 Into an MGB
Posted by: mgb260
Date: December 18, 2014 08:24AM

Scott, Your swap is quite an achievement! As far as I know, the first LS4 RWD with block mounted starter! Others will soon follow.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5379 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: LS4 Into an MGB
Posted by: BlownMGB-V8
Date: December 18, 2014 10:17AM

Seems to me you'd be better with a VSS mounted to the driveshaft near the transmission as it would not be moving around all over the place like the diff will. But then I suppose it will be moving forward and back. And a cable speedo would mean you can't use the electronic plug-in at the tailshaft. I think there was a combo cable drive VSS pickup but have no further info.

Jim


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 18, 2014 12:40PM

Jim N., Thank you, I really appreciate it!

Jim B., As always, I appreciate your input! The approach to mounting the VSS on the differential isn't my idea at all. A vendor, I think it was Jag's That Run, was offering a kit that used a GM sensor. I took their idea and did the same thing for my V6 swap. Ran that for almost 10 yrs. with no issues. I don't see any reason for changing the approach at this point. I've got it all wired up, just need to build the mounts. You bring up some interesting points though.


74ls1tr6
Calvin Grannis
Elk Grove,CA
(1112 posts)

Registered:
11/10/2007 10:05AM

Main British Car:
74 TR6 / 71 MGB GT TR6/Ls1 71 MGB GT/Ls1

authors avatar
Re: LS4 Into an MGB
Posted by: 74ls1tr6
Date: December 20, 2014 09:52AM

Just a thought, I believe your VSS pulse is what an electronic speedometer uses. The Autometer speedo is what I have used, needs that pulse. I guess that is how your setup works too? Are you using electronic or mechanical speedo?


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 20, 2014 05:10PM

Calvin,
I'm using the stock gauges so a mechanical speedo. The main reason I'm including the VSS is because the PCM needs to know if the car is moving or not. Another reason is I'll be installing factory cruise at some point so it will be needed there as well. I'll be using a 4 tooth "reluctor" and Sinister configured code to work with it. Actually, I believe the PCM needs the number of pulses that will be generated per mile with your rear end and tire size. Sinister Performance sends a fairly long questionnaire you fill out before he does your PCM. Both the sensor and "reluctor" wheel will be mounted to the rear end so the gap will be static if I do my job correctly and make the mount ridged enough.


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 21, 2014 10:30AM

Kelly was exactly right. The header flange is warped. It bows out in the middle so the middle two cylinders are leaking like a sieve. Need to address that soon. Made good progress on the throttle pedal yesterday. I'll share it when it is complete. Here's a shot of how the starter fits. Been meaning to get one of it for a while and finally had the chance yesterday.

LS4StarterInstalled.JPG


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5379 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: LS4 Into an MGB
Posted by: BlownMGB-V8
Date: December 21, 2014 11:36AM

On the BOPR it is possible to separate the port flanges once the header is made, which goes a long way to eliminate the warpage problem. MLSS gaskets are a great option if they are available.

Jim



kstevusa
kelly stevenson
Southern Middle Tennessee
(820 posts)

Registered:
10/25/2007 09:37AM

Main British Car:
2003 Jaguar XK8 Coupe 4.2L DOHC/ VVT / 6sp. AT

authors avatar
Re: LS4 Into an MGB
Posted by: kstevusa
Date: December 21, 2014 01:51PM

Scott, The machine we used was a giant Belt sander (rather than a circular stone on a table). Course medium and laid the flange flat on the belt and removed material until the pattern was even accross the entire surface. Size- 2'W X 4'L- pretty large belt sander :-)


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 21, 2014 04:40PM

Quote:
On the BOPR it is possible to separate the port flanges once the header is made, which goes a long way to eliminate the warpage problem. MLSS gaskets are a great option if they are available.

Jim, that's an interesting idea. I could split it in half but not into fourths because of the way the bolt pattern is laid out. I'm going to think on that one.

Kelly, I'll figure something out. I don't have access to a belt sander like that though. Thank you for pointing me in the right direction! How's that Jag doing? Can't wait to see it!


mgb260
Jim Nichols
Sequim,WA
(1831 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: LS4 Into an MGB
Posted by: mgb260
Date: December 21, 2014 06:35PM

Scott, Maybe a hydraulic press to straighten?


Scott68B
Scott Costanzo
Columbus, Ohio
(501 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: LS4 Into an MGB
Posted by: Scott68B
Date: December 21, 2014 07:23PM

Quote:
Scott, Maybe a hydraulic press to straighten?

Thanks Jim! That's exactly what I was going to try next time I get out in the garage. Won't cost anything and won't take long do, worth a shot!


MGBV8
Carl Floyd
Kingsport, TN
(3260 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: LS4 Into an MGB
Posted by: MGBV8
Date: December 21, 2014 11:02PM

Cut the middle two tubes, straighten flange, bolt flange to two full length pieces of angle iron, & reweld center tubes. :)
Goto Page: PreviousFirst...7891011121314151617...LastNext
Current Page: 12 of 22


Sorry, only registered users may post in this forum.