Question : 3.4 - LIM Oil Leak and Other Questions

[cdcollins1]

I've swapped out the wimpy 4 cylinder in my 78 MGB with a 3.4 from a 95 Camaro. Bored .020, mild cam and fuel injection should make it a pretty quick little car at 2200 pounds.

I fired it up for the first time last week and had a couple of oil leaks. The oil pump drive o-ring was hard and brittle, replaced that and added a gasket under the top flange which stopped 90% of the leak.

I still had a weep of oil in the back valley which was enough to run down the sides onto my exhaust. So I added some UV leak detector and found that he LIM was leaking across the back mating surface to the block.

So I pulled the intake off and saw that I had not put a bead of silicone along the top edge of the block between the heads when I put it together. I'm using FelPro gaskets.

Questions:
1) Should I replace the LIM gaskets? Are they re-usable? aside from having to reset my valve lash, are there any pros/cons to replacing the ones that are on there? I've only got 30 minutes of run time on the motor.
2) While I've got it torn down to this point, should I re-torque the head bolts? Would that require me to remove, replace and reseal the head bolts since the final torque isn't a stated value, but 41 Ft-lbs + 90deg? Or should I just leave them alone?

Thanks,

Doug

[Purple pit]

I'd use new gaskets.

[robertisaar]

I've seen them reused with success, but I've also seen it end pretty badly too.

as for the the headbolts, you're not using a headgasket that specifies retorquing, are you?

[Guest]

If it were my engine and the gaskets still looked good, I'd re-use them, but they would have to look just like new...

I'd also leave the head bolts alone. I've never needed to re-torque TTY head bolts.

[cdcollins1]

Thanks for the replies.

I have a complete new set of FelPro intake gaskets and will replace them (along with a bead of RTV on the front and back of the block).

Probably not a bad idea to check the valve lash since I'm not sure what the shop who built it for me used for final setting (1 1/2 or 1/2 turn past zero lash). I'll set them to 1/2 turn when I put in the new gaskets just to be sure. He did put in SBC valve springs just in case I decide to go with 1.6 rockers at some point. Any difference in setting the valve lash with something other than stock springs? I wouldn't think so.

Wasn't sure about any need to re-torque the head. I'll leave it be.

Here's how it sounds without the exhaust on it.

78 MGB V6 Conversion: https://youtu.be/zG63CsxpoNQ


Thanks,

Doug

[Purple pit]

Oh crap I just saw where you are from. I think that I saw your car on an MG site when searching for parts/mod for the 60 degree. PV right? Got a few(not many, but it would be a start) 3in aluminum tubes with bends if you are planning to build an intake. We can talk about it in a PM if you want them.

Boy that thing sounds good!

[cdcollins1]

Purple pit,

Not me in PV, but there are several of us in KC with V6 conversions in our MGBs. I might reach out to you on the intake tubes. Right now I have an elbow off the throttle body and the air cleaner is sitting right behind the radiator. Not ideal and I'd eventually like to do more of a cold air intake as a performance enhancement. For now, I'm just looking to get it on the road and work the bugs out. Even with my "Hot Air Intake" system, I don't think I'll be short on power.

[Purple pit]

Bet your right on the power, sure sounds mean. Man I didn't know that there were several MGB V6's around here. I've seen a very tall older man with a fully restored/or mint MGB and a say 79(?) with faded paint in the past two years.
Sounds good on the intake tubes, I hate having parts sitting around when someone could use them.

[cdcollins1]

Intake Tube Parts

Bet your right on the power, sure sounds mean. Man I didn't know that there were several MGB V6's around here. I've seen a very tall older man with a fully restored/or mint MGB and a say 79(?) with faded paint in the past two years.
Sounds good on the intake tubes, I hate having parts sitting around when someone could use them.

Hey Purple Pit,

You still got those intake tubes sitting around? I'm looking for some 3" tubes to set up my cold air intake so I can re-route it and then install my new puller fan.

What parts to do you have? I'm looking for a 90 degree elbow and a straight piece about 12" long, maybe some connectors if you have them.

Thanks,

Doug Collins

[Purple pit]

Got the PM and sent one back.
I'd have to dig around in my favorites, got a few sites in that very long list that have straight pipes and even 22.5 couplers(very rare). That is if you have not already found a place to buy them from.