Manifold Primary Lengths

[kevin the chicken]

I am currently on the last few stages of my engine change and am trying to fit a stainless steel 4 into 1 manifold I got cheaply from ebay. It's a bit of a tight squeeze getting it in position between the engine and side of the car but I think I may be able to get it in by removing a few bits and bobs from the engine and the engine bay. If I can't would the performance be affected greatly by removing a small piece from each primary Pipe?

I know someone who could do it for me and I am talking about only 5 or 10mm.

Hopefully it will go in anyway but it would be good to know in advance.

Regards all

Kevin

[Guest lotusPaul]

No it won't is the simple answer. We're talking a pony and a foot of torque difference. However to be sure you only need comp ratio, valve timing and a few others to get the exact length AND diam requirements. As your keeping the pipes it won't make a huge difference.

[Bob Tucker]

+1 with Paul.....no noticable difference at all.

The manifold I ran with that engine was built by an expert, but he couldn't make the primaries

identical, and get it to fit without huge expense.

I have a 6 inch difference between longest & shortest primary & still turned in

210 bhp & loads of torque. You said it has bigger primaries than your old manifold,

so it will be working better in any case.

Dont worry about squeezing every last HP.....you will have enough to keep you smiling as it is...

[kevin the chicken]

No need anyway. Managed to get it in by taking the thermostat housing off and jacking the engine up slightly, once it was on the studs there was plenty of clearance.

It was difficult trying to work out where to trim the body panels so that it would go in but Claire had the idea of making a flexible dummy manifold out of rolled up chicken wire so that we could see if our measurements were on the right track. First attempt was too small so cut another 10mm out and it went straight in. Clever girl. Not the first time she's got me out of trouble.

[Bob Tucker]

It comes from watching Blue Peter......maybe even with the kids!