is it true about manifolds notoriously warping?

[pascualid]

Is it true that datsun intake manifolds are notorious for warping? I have one on l20b that will not stay tight long. Will motor wel for awhile then lay down. Sparying carb cleaner reveals that it is leaking all along the top of the manifold where it bolts to block. New gasket too. Thank you.

[]2eDeYe]

You can check to see if it is warped by pulling it off and laying a straight edge on the flange. If it's warped you could get it milled flat or pick up a new one.

 

It's not unheard of, but I wouldn't say Datsuns are notorious for it. I would just say aluminum is an interesting material ;)

[kiznook]

I would be hesitant to assume it's warped. These motors ARE notorious for having hard to reach manifold bolts.

 

Do you have a header, or stock exhaust manifold?

[datzenmike]

Are you using a header? The bottom bolts use a large 'washer' to hold the intake and exhaust manifold. If the two flanges are different thicknesses then the bolt and washer won't clamp properly.

 

I don't see how it could leak at the top, there are two large bolts on each runner to clamp it on. Are the two surfaces clean and undamaged? Is this intake separate from the exhaust or are the two manifolds clamped together under the carb?

[pascualid]

Ok thank you. The manifold is just stock and yes it is under the carburator , which a burdon to remove and install, and clamped to the top of the exhaust manifold. I put a plate between the block and egr recirculation passage and blocked the vac. line from the thermal heat sensor ot egr, but left all the stuff on including the air galley which is an obstacle. I don't think that stuff was working properly and at any rate this problem was occuring before I made these changes. Thank you.

[banzai510(hainz)]

sometimes if a weber DGV is installed there is a cheap thin carb adapter than when to tight it will crack.

 

If this is stock I dont know.

I know the latter L20s was a pain in the ass to get those bolts and all the crap in the way.

This is why I like the L16 intakes and exhaust manifolds.

[ggzilla]

A lot more common than warping is overtighening. The manifold nuts should only be about 15 lb. ft. Use a torque wrench, it's not very tight, but every one should be tightened the same.

[Llittle_Llama]

so about the thicknesses, can you run an L16 intake and an L20 exhaust? imma try and find an L16 exhaust asap, but can i go ahead and put the intake on now?

[datsunfreak]

can you run an L16 intake and an L20 exhaust? can i go ahead and put the intake on now?

 

 

Yes you can. If you can't find one locally, I have like 6 of them... :P

[Llittle_Llama]

is there much difference? what would you want for one shipped to 36322? will i notice any difference?

[datsunfreak]

is there much difference? will i notice any difference?

 

The main difference is the lack of smog gear. As in no EGR, not heat riser, etc. Just nice and clean. :D

 

Port size is slightly smaller than the L20b, which helps torque, but can limit top end. But that's an L20b's forte, torque over top end. ;)

 

what would you want for one shipped to 36322?

 

Probably about $40 should cover it all. Email me if interested. john@roper-photo.com

[Llittle_Llama]

let me look around a little bit, i really cannot afford 40 right now :( i can send you a 40 dollar autozone gift card......lol

[datsunfreak]

let me look around a little bit, i really cannot afford 40 right now :( i can send you a 40 dollar autozone gift card......lol

 

Hell, that might work... But how do I guarantee it's good? :D

[Llittle_Llama]

i've got a few of them, let me find one that has like 40 or 45 on it and i will mail out tomorrow. i can send paypal too and you can refund as soon as you verify the card is good that way you can mail out tomorrow....well monday i mean.....

[datsunfreak]

Either way is fine. Email me...