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Author
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Topic: Cleveland Head Question
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73STANG
Journeyman Posts: 76
From: Lincoln, NE
Registered: APR 2000
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posted 12-18-2000 04:22 PM
I have decided to build a street strip 377 stroker Cleveland. It will have a manly not a girly cam. Probably a roller. The question I have is what areas of the ports or bowls to do work on the stock closed chamber 4V heads. Or do they flow the best when left alone?
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kid vishus
Gearhead Posts: 6006
From: middle of NC
Registered: OCT 2000
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posted 12-18-2000 04:36 PM
They definately flow better with work done to them. Here's what I do, on the intakes, just up under the valve needs blended, remove the sharp edges and strange "flats". I also lay the short turn back just a little, not much though, water under there. Plus I also neck down the guide boss to reduce it's restriction. I don't do anything in the port itself, they're already big enuff for most applications. Plus in the chamber, find a shop with a Serdii, and have them put a 45*(I think that's the right angle) cut on the back of the chamber by the intake to unshroud it, helps low lift out.
On the exhaust do the same under the valve, and in the port, remove the bump on the roof, raise the roof up to the gasket and I also knock dowm most of the bump in the wall where the head bolt runs, gives it a lot straighter shot out. If you break thru, it's not a prob, cleveland's head bolts are dry decked so there is no water in there, but you already knew that.
I'm sure others will have some other ideas since clevelands are a hot topic here.
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73STANG
Journeyman Posts: 76
From: Lincoln, NE
Registered: APR 2000
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posted 12-18-2000 05:23 PM
Do you have to polish the intake ports or just leave them rough? I have heard about raising the roof of the exhaust port to the gasket edge. I like your arctic circle location. It's not much better here in Nebraska. 10 inches of blowing snow. I guess I have plenty of indoor work porting my heads.
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kid vishus
Gearhead Posts: 6006
From: middle of NC
Registered: OCT 2000
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posted 12-18-2000 07:04 PM
Actually I'm in Iowa,but it gets confusing when you go outside for any length of time.
I just leave them rough, I only polished one set and that was for a motor I put on alcohol. But I don't think it really helped that much. Knocking down the bolt bump in the exhaust seems to help a lot too. I polish them as slick as I can get 'em.
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perk
Gearhead Posts: 339
From: Staley,nc
Registered: SEP 2000
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posted 12-18-2000 08:11 PM
Would you recommend the same for 2v heads,as far as the intake side goes.I was already planning to have the exhaust side done as you have spelled out.
perk
[This message has been edited by perk (edited 12-18-2000).]
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DutchD58
Gearhead Posts: 125
From: West Milton, OH
Registered: JUL 2000
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posted 12-18-2000 09:14 PM
Just wanna throw a couple quick questions in on this one concerning valve guides:1) do you leave the guides stock length or shorten them? 2) are you running solid bronze guides, or thinwall steel backed bronze liners? 3) when you contour your guides, are you going to the trouble of "tear-dropping" them down the port centerline into the pocket, or just whittling them down to get rid of some of the mass? Thanks,
Kevin
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kid vishus
Gearhead Posts: 6006
From: middle of NC
Registered: OCT 2000
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posted 12-18-2000 11:21 PM
perk,
for the 2v heads on the intake I actually open them up some, they don't flow real well as is so I try to improve that. I raise the roof up to the gasket, and where it makes the bend I try to knock some of that down to, but remember, I run loose convewrters on the street so low end power isn't of much concern.
Dutch,
I leave the guides the stock length, I run solid bronze guides. I run rollers in my race motors and we put about 250lbs on the seat, and my machine shop guy doesn't like the thin wall liners for that load that gets put on them. I guess you could say I tear drop them on the intake, I try to take most of the sides and put somewhat of a point on the front and leave the back fairly round. On the exhaust I just try to reduce as much of the mass as possible, plus knock down the sharp edge of the boss to help reduce turbulence.
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Rustang1
Gearhead Posts: 110
From:
Registered: NOV 2000
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posted 12-19-2000 12:32 PM
Vishus, concerning the laying back of the combustion chamber near the intake valve at a 45; are you refering to where the valve is closest to the cylinder wall, or the near the quench area. The reason I ask is that I've seen old magazine articles for NASCAR-prepped 4V heads where the chambers have been "rounded" where the chambers are cast straight(where the chamber goes out around the spark plug). Is anyone familiar with this chamber reshaping and is it much benefit? I wonder because the cleveland head needs alot of ignition lead, and maybe this helps make the chamber more efficient from this standpoint?
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kid vishus
Gearhead Posts: 6006
From: middle of NC
Registered: OCT 2000
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posted 12-19-2000 08:27 PM
On mine, Where the chamber is right next to the valve and actuallly runs around it, we lay that back to unshroud the intake valve. I have never seen the chamber reshaped so I do not know on that part. I do knock down the sharp edge by the quench area. don't know if it helps or not, but I'm more comfortable with NO sharp edges in the chamber area.
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