Scored Some Gt40ps. Need Some Diy Direction Please.

[poboys 94]

Hello all, need some advice for my cheap junkyard budget head build. My initial plan is to clean them up, do some port work to them, lap the valves install stiffer drop in spring kit from Alex's and run em..Can I check them accurately for cracks myself using metal shavings from a brake lathe and a magnet? Can I check them accurately for straightness myself? Is there a way to check for worn guides and leaky seats?..Trying to save $$ as I am also going to pull another set to freshen up and put on my Explorer..Any advice and pointers would be great! Do they look OK from what you guys can see

 

[jrichker]

MagnaFlux typically uses powered iron and a very large magnet. Any kind of NDI (Non Destructive Inspection) requires that you clean all the carbon and sludge off a part before testing it. That's why a dip in the hot tank and carbon removal is standard part of automotive machine work. Knowing where to look is just as important as knowing how to look.

See
View: https://www.youtube.com/watch?v=Oag_fnwG5F4

 

[poboys 94]

Wow very interesting. That's a very fine powder. I sure don't want to skip that. Off to the shop they will go then. You think it would save a little labor money if I removed the valves and springs and drop them off bare to have them tanked and fluxed?

 

[stykthyn]

Unless you are lapping and installing your valves, keepers, and springs yourself there's really no point in disassembly. Just drop them off.

 

[mikestang63]

spend the money and have them hot tanked and magnafluxed before you invest any money in parts. You will want them to install new guides and probable a light mill as well. I prefer the TFS springs over Alex's. It's going to run $3-400 to do it right, assuminng no bent or bad valves and you dont need to regrind the seates/Those heads look like they ca,e offf a high mile engine with a lot of carbon in the chambers. What's with the rust? Have they been sitting outside or did a HG go?

P heads require a different set of headers than normal GT40 due to the plug angle.

 

[poboys 94]

spend the money and have them hot tanked and magnafluxed before you invest any money in parts. You will want them to install new guides and probable a light mill as well. I prefer the TFS springs over Alex's. It's going to run $3-400 to do it right, assuminng no bent or bad valves and you dont need to regrind the seates/Those heads look like they ca,e offf a high mile engine with a lot of carbon in the chambers. What's with the rust? Have they been sitting outside or did a HG go?

P heads require a different set of headers than normal GT40 due to the plug angle.

The coolant runners are really gummed up and scaled, the truck had 167000 + on the clock, If it blew a HG I would think there would be evidence of a steamed cleaned cylinder or 2..it has been in the yard since March..I called a shop I used to deliver parts to years ago, same owner, quoted $60 to tank and magnaflux them both..Other then engine looking like it never had a coolant flush, and 2 broken intake bolts I snapped off at the front coolant runners removing the intake, they appear to be rebuildable assuming the shop says they are crack free..Whats better about the TFS spring kit? I have a new pair never installed set of non P headers that I purchased from Summit, rough sanded and shot with 3 coats of silver high temp for sale or trade for a set of Ps..

 

[stangin47]

The bbk 1515 shorties work fine. The TFS spring kit has stronger spring which enables you to run a bigger cam at higher rpms. depending on your cam you may want to look at other kits but if your running a low lift stockish cam you will be ok.

 

[mikestang63]

The HG could have been failing and causing coolant to leak out the top of the gasket not into the cylinder, but that looks like they have been sitting outside for a while. Regardless, the machine shop will mill them straight if after the magnaflux says they are ok. The TFS springs are better quality and strength as Alex doesn't say his source and if I remember correctly the TFS comes with retainers and/or keepers. If you plan on running a cam with a mild ramp up and not exceeding .525 lift, then Alex's springs should be ok.

167k miles is a lot and I would be surprised if those seats and guides are not shot. If it were me, I would add up the cost of hot tanking, milling, magnafluxing, guides, seals, valve job, and also if any valves are bad. If it comes out to more than $4-$500 to complete the heads properly, I would save up for a set of new TFS or AFR's. Personally I am not a big fan of P heads as changing the plugs are a PITA.