1978 620 vg30e
Posted 12 January 2018 - 12:19 PM
simple works for me now as I'm just learning to tig. I would like to try n make some crazy looking headers, but my skills and space limit me. Ahah
I love the classic simple look of a log manifold. They don't always work great, but a turbo motor won't care as much.
Posted 12 January 2018 - 12:26 PM
Yeah you will need to allow room for expansion, especially being a straight section of tube it will grow like 3-5mm when hot and will break exhaust studs. It needs to be able to move. If you look at the standard mani it will have 2 holes that are small just to go round the stud for a accurate location when installed, the others will be a lot larger and a loose fit to allow the manifold to move around when hot.
Put a 300mm length in your vice and heat it to 400*C and measure it when hot. The other thing is the header plate itself will also grow and then the pipe and plate will be fighting to move.
I think the log mani will be fibe for the HP required to make a 620 terrifying on the highway in the wet! Nice smooth transitions into the merge from both banks, no sharp turns before the turbo and it will be sweet. What tubing are you using for the cross over?
Are the standard turbos divided? If so keep your mani the same, I prefer to have the wastegate work from both banks though.
Have you had an eye over "maximum boost" by Corky Bell? Good book. Follow as many tips as you can and dont get hung up on what you cant and you will be surprised how good it will work. Helped build some low budget cars that have been better than the ones with every brand name in the catalog by following sound principles in that book.
Yea I noticed that some of the holes were larger. I wouldn't want to snap some studs. It would be a nightmare to replace them. I will cut some slots in between each cylinder. I was thinking of using the stock crossover pipe. Imy goinghia to delete the internal wastegate and go with external. No I haven't, I will take a look at it for some insight. Thanks man
- Str8jacket likes this
Posted 12 January 2018 - 12:28 PM
sounds like a plan to me aha
Get it sandblasted then hit it with enamel clear. It will look like stock.