OE Iron head 355 holden street/strip - 636hp

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Re: OE Iron head 355 holden street/strip - 636hp

Post by Carnut1 » Fri May 18, 2018 9:47 am

What, no super sexy ported intake and port pics? Awesome build Tony!
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Re: OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines » Fri May 18, 2018 9:55 am

Charlie - intake is as cast other than a port match a couple of inches up the runners.
Heads are sanded finish, 40 grit intake and 60 grit exhaust and chambers with polished short turns. I dont think I have many pics.
Plain ol 45 deg seats, 35/45/65/80 valve job (my faux 50 deg valve job - acts like a conservative 50 deg valve job but with the durability of a 45) with the 80 blended into the throat and the 65 blended into the short turn. Exhaust is 35/45/radius. Both have radius chamber sweep cuts. Intake is .040 on the contact, exhaust is .050.

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Re: OE Iron head 355 holden street/strip - 636hp

Post by Carnut1 » Fri May 18, 2018 10:19 am

KnightEngines wrote:
Fri May 18, 2018 9:55 am
Charlie - intake is as cast other than a port match a couple of inches up the runners.
Heads are sanded finish, 40 grit intake and 60 grit exhaust and chambers with polished short turns. I dont think I have many pics.
Plain ol 45 deg seats, 35/45/65/80 valve job (my faux 50 deg valve job - acts like a conservative 50 deg valve job but with the durability of a 45) with the 80 blended into the throat and the 65 blended into the short turn. Exhaust is 35/45/radius. Both have radius chamber sweep cuts. Intake is .040 on the contact, exhaust is .050.
Similar valve job to my Dart 215's, has a pretty strong flow curve. thanks, Charlie
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Re: OE Iron head 355 holden street/strip - 636hp

Post by DrillDawg » Fri May 18, 2018 10:21 am

I only made the comment about MT as he advertised that headers like that would spread the power band and make the same or better power as conventional headers. Sweet engine and you make it look easy.
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Re: OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines » Fri May 18, 2018 7:42 pm

I'm forced to use a lot of tri-y headers due to space restraints, in my observation a good set of tri-y's will give up very little peak to 4-1's & do produce a wider curve that hangs on after peak.
Shelf tri-y's are often designed for mild street engines, methinks that's why a lot of people think they can't make power. But built with making high rpm power in mind they work pretty damn good.
The headers on this one are far from ideal, there is probably a solid 10hp hiding in a set of custom pipes, but that handful of extra horses would come at a significant cost so shelf pipes are fine!

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Re: OE Iron head 355 holden street/strip - 636hp

Post by cjperformance » Fri May 18, 2018 8:34 pm

KnightEngines wrote:
Fri May 18, 2018 7:42 pm
I'm forced to use a lot of tri-y headers due to space restraints, in my observation a good set of tri-y's will give up very little peak to 4-1's & do produce a wider curve that hangs on after peak.
Shelf tri-y's are often designed for mild street engines, methinks that's why a lot of people think they can't make power. But built with making high rpm power in mind they work pretty damn good.
The headers on this one are far from ideal, there is probably a solid 10hp hiding in a set of custom pipes, but that handful of extra horses would come at a significant cost so shelf pipes are fine!
And got to say that unless its a real full effort streeter with money to burn good tri-y pipes are fine and also add some space for hot air exit around the engine which helps not turn the cabin into an oven like a real stuffed fit 4 into 1 set can. Not to mention the typical extra ground clearance we need with the speed humps and general road conditions here!
Craig.

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Re: OE Iron head 355 holden street/strip - 636hp

Post by DrillDawg » Fri May 18, 2018 8:36 pm

They look like well made pipes. Most tri-Y's are shorter than those and Mickeys, Mickey called the pipes that connect the collector to the primary pipes his power "Y". I think one of the 2018 EMC entries used some headers something like those and scored very well.
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Re: OE Iron head 355 holden street/strip - 636hp

Post by CGT » Fri May 18, 2018 11:27 pm

DrillDawg wrote:
Fri May 18, 2018 8:36 pm
They look like well made pipes. Most tri-Y's are shorter than those and Mickeys, Mickey called the pipes that connect the collector to the primary pipes his power "Y". I think one of the 2018 EMC entries used some headers something like those and scored very well.
Yeah. It won 1st place.

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