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TR6 TR6 Intake Manifold interchangability

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gtemkin

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From what I've learned online, the two different stock TR6 Intake Manifolds are intended to be used on their corresponding port spaced heads. I understand that, but my question is, are the alignment pin locations identical in all situations so that it's possible for an incorrect manifold to be installed on the wrong head, or is the pin spacing different to prevent that?

Thanks.
 
Pin position don't matter
Holes don't line up
 
Thanks for the quick response. I'm kinda confused by "Pin position don't matter Holes don't line up".

Are you saying the alignment pin holes in the manifold are at different locations for old and new style manifolds, and only the correct manifold could be fitted to the correct head?
 
The ports in the old head don't line up with the ports on the later manifold
 
Yes, that I know. My question is do the alignment pins that are mounted in the head line up with their respective intake manifolds only or is the pin pattern universal?

I understand that the alignment pins should be of little consequence - they could just be removed - but I have an engine that someone told me had the "wrong" intake manifold. I had assembled it, so I know the pins are in place and going through the intake holes. Is that, in itself, proof positive that the correct manifold is being used for that head?
 
If you have the intake on the head then the intake is correct
You cannot possibly put an newer intake on an older head
If I still lived in the Emerald City
I'd take a look\


What the person might be saying is that the manifold is not correct for the year of the car
 
Thanks very much. That's the info I needed. It's actually a '74 TVR that had it's original engine replaced and what it has now is a non-EGR single spring head and a newer style intake. They didn't think that combination existed and that I must have the wrong intake on there.
 
It's been years since I had my hands on an early manifold, but it seems like the bolt patterns are the same. Which means you could mount the wrong manifold on a head.
I may still have intake manifold gaskets for both the old and new heard. I'll try to remember to check tonight.

BOBH
 
Sorry guys,

I was very late leaving work last night. I'll try to check over the weekend.

BOBH
 
"You're fired" That means I'll have more time for toys, but no money.

OK I checked the gaskets. The bolt patterns are the same. Placing the early model gasket on the bench and laying the late model over it, then matching the bolt pattern as well as the exhaust ports. I could see the early intake ports protrude approximately 1/4 inch into the late intake ports. I used my calibrated eye to measure.

GT,
I think that unless you hapen to have a UK market head you have an early head with a late manifold. (As far as I know the only heads that had EGR were the US heads from 72 or 73 on) You definitely need to verify what you have before you try to run and tune the engine. Remove the intake and masure the distance between a pair of intake ports on the manifold. Then measure the distance between a pair of intake ports on the head. From what you describe I believe you will find there is a difference. Using a late model intake on an early model head blocks a significant amount of the port.
The late model head already has better flow. If you decide to increase the compression or clean up the ports. The late model head will respond better.

Take a look here for more detailed information

https://www.tr6.org/cylheads/index.html

The 219016 head discussed in the article is basically the same as the late model heads used for the US market. The US version has lower compression and an EGR fitting. Both of which can be "fixed" if you like.

BTW, I have a 74 TVR patiently waiting for me to either retire or get fired so I can begin the restoration. Back in the day I had a 71 TR6 and a 73 TVR. At one point I had both TVRs. I sold the TR6 to raise money for tuition. Sold the 73 TVR because I couldn't keep them both.

BOBH
 
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