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Author Topic:   Bummer!!!!!!
shaggy12
Member
posted June 03, 2003 09:42 PM
I am currently building a cyl. head for a customer. He requested larger valves and MILD port work. Nothing fancy, just to clean up the ports and to match the throats to the seats. Here's where it gets ugly. I spy a crack in the casting between the guide boss and the guide in the port. Actually two cracks, one in the exh and one in the int. By the way this is a 2.3 ford head. Right now I think I have two choices......scrap the head, or.....grind down the guide boss to match the contour of the port and then install another set of guides. I've never ported one of these heads in this manner but it might just work. Got any suggestions???? Please don't mention the word anchor or door stop in your reply!!!!
thanks Chad


sdhnc29
Member
posted June 03, 2003 09:56 PM
If I understand your description correctly , the guide boss is cracked all the way through . If the rest of the head mag's ok , I'd do like you said and contour the valve pocket , then install false guides . It's rare to see one cracked there , so be sure to mag the combustion chamber where it's common to see the 2.3 head crack .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


shaggy12
Member
posted June 05, 2003 09:58 PM
Thanks for the response.......as far as to mag the head, it's ok. Everything checks out ok. To be honest, after looking at the head in disgust, it's possible that I caused the problem when installing bronze guides. I have miked and miked my reamer and it appears ok, but stranger things have happened. The reamer measures .500 the bronze guides measure .5025 I didn't run a hone through before installing them......never had to before. Suppose they're too tight???? As far as the cracks go, you mentioned 'cracked all the way through'. Yes and no. I see the crack looking at the guide from the chamber side. I removed the guide to find the crack about 1/4" down the bore and yes all the way through heading into the port. I've started to grind, following the contour. I've only just begun and the crack has already disappeared. What a relief!!!!!! What kind of clearance do you use when installing bronze guides?? Thanks Chad


sdhnc29
Member
posted June 06, 2003 12:14 AM
Hey Chad ,

I don't actually use a full 1/2" false guide in any stock type head anymore . I've been using thin wall bronze guide liner's from Goodson . Just estimating , they are about .025-.035" thick . Check with Goodson , they sell complete kit's for different size guides . I'm heading out for a weekend vacation in the mourning or I'd give you the part number's on the set up that I'm using . If you can't find them , I'll give the info to you on Monday .

I would say that .0015-.0025" press fit should be just fine in the guides your using .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

[This message has been edited by sdhnc29 (edited June 06, 2003).]

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