porting injector housings to 36MM

[tpepmeie]

You are tirelessly focusing on size with the assumption that mm=hp. The critical issue in the inlet tract is getting the air to turn (with minimum pressure drop) at the junction between the head port and housing port. Yes, you can use sheer size to overcome that drop, but doesn?t mean the whole port has to be uniformly large. The factory as-cast injector bosses are the other obstacle.

Marc does great work. And he has refined it over the years. There are others too, but don?t get hung up on size...

Maybe tell us more about your build and goals for it?


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[wfot]

Marc does excellent work and a very generous man with his time and knowledge.

I do understand that the turn from the housing to the head is important and I am looking at it like the turn at the short side radius at the valve.. it needs to be done right or the flow will cause turbulence. I feel that port matching the gaskets is an often overlooked basic necessity.

I am developing a way of raising the secondary Oring to mimic the primary Oring location, thus allowing the Oring boss to be removed completely from both ports. so far a 36mm drop thru port like that has about 100ML of volume vs 80ML for stock 405 hp prim/secd ports.

as far as the build
-402 CID/12 to 1 compression
-thinking 36mm ported housings raised Orings on the secondaries
-siamised runner plenum, considering a dropped plenum, but am not sure if a 402 needs this OR ti is just something that no one has wanted to invest in a 402 build ( I have only seen them on 415+ CID motors)
-ported air horn with large throttle body
-stage III cams
- large valve/ported heads
-Jeal headers

I am shooting for crank 630HP or 550 RWHP, hopefully more. I am aware of 2 402/408 builds that have seen between 500 and 550 rwhp with similar parts as I have outlined above.

Again I am basing my posts on what seems to be the accepted things that have worked for people. I have had a lot of positive and negative input from many forum members that I appreciate greatly. There is a lot of good information out there and I am piecing together the parts that I think will work best for my goal.

John

[tpepmeie]

Who?s doing the heads and what size valves?

What rpm do you expect peak power?

Last time I measured the injector housings, they were about 4" long centerline (101.6mm). From that you can work out either diameter or volume, if the other is known.

[wfot]

I got the heads already ported, I believe they were actually done by bill krichoffner for kurt white's old 415 from way back, the valves are 41.5mm and 35.5mm stainless. the chambers have had some smoothing/unshrouding done, but I think they could use a little more. Ti retainers/secondaries removed.

I understand that the stage III's have a pretty high peak RPM, so I am expecting peak between 6900 and 7350 or so..

[tpepmeie]

Originally Posted by wfot

I got the heads already ported, I believe they were actually done by bill krichoffner for kurt white's old 415 from way back, the valves are 41.5mm and 35.5mm stainless. the chambers have had some smoothing/unshrouding done, but I think they could use a little more. Ti retainers/secondaries removed.

I understand that the stage III's have a pretty high peak RPM, so I am expecting peak between 6900 and 7350 or so..

The oversize inlet valves back then were typically 1.600" inches / 40.6mm.
Bill is a great guy, I just talked to him a few weeks ago.

This is a 402" engine? 4.00" stroke?

compression? << nevermind, I see 12:1>>>

[wfot]

caliper says 41.5mm across the thickest part of the head

I also have one of bill's 12mm studded blocks, 12mm studs on all mains very nice work indeed. The thing is a tank. I hear good things about him as well. I think that was kurt's actual 415 block as well. From what I read, Kurt was going all out with that build and Bill did the work. It does look good. the heads are very nicely done. But I do not have any other LT5 heads to compare them to. Might do some bowl work and match the ports a little, but they are pretty much ready to go

and yes 4.00 x 4.00 motor, bryant crank.. work of art

I am planning on 12 to 1, but if head gasket selection can get me to 12.25:1 or 12.5:1 I would do that a well

[tpepmeie]

Originally Posted by tpepmeie

The oversize inlet valves back then were typically 1.600" inches / 40.6mm.

I have to correct my post above after talking to Bill. The correct measurements for the valves he installed are: intake 1.580" or 40.132mm and exhaust are 1.445" or 36.703mm.

Perhaps Kurt had additional machining done and new valves after Bill did the initial work?

[wfot]

I bought a 402 "Project" package a few years back. I am almost positive the block is kurt's and was done by bills. the heads I cannot be so sure of. so anything is possible, especially given the many years that have pasted.

for instance;The manifold is a true siamised manifold, the outside it beautiful but the inside is a mess. have no idea who did those but they were done for ecstatic purposes I am sure. The housings are a mess and have various port sizes and there is some serious weld overlap on the plenum. it is taking a long time to figure all of this out and actually get things into shape but it is coming along well.

If this was a typical small block build in the end, no way I would put this much time into it... lol

[tpepmeie]

Hmmmm. I think I recognize that description. Many years back there was a gentleman on this forum (Kevin P.) who spent a ton of money building a 402 using parts sourced from Bill. This would have been 2009-10 time frame. I forgot his screen name, but he and I chatted several times about that build. At the time I was building my first 427 and we would friendly jab each other about which had the nicer parts!

PM me if you want to discuss.

[Polo-1]

Originally Posted by wfot

I bought a 402 "Project" package a few years back.l

Hello
I tried to send you a pm on this 402. It might be my old 402. I have lost track of who owns it now. It went through a few hands.

Kevin