FueledSoul

iTrader: (18)

I picked up a set of used LT1 heads (casting #643) for $170 shipped

(Disassemble)
I clean the chambers by soda blasting them (using a home made blaster at the time) I numbered the valves. I left a broken spark plug in one head and coolant fitting in the other to easy identify the location and placement of each valve prior to reassemble. After the valves came out i labeled each one on the stems, i made numbers on paper with a marker i cut them out then clear tapet it over the stems. I did a visual inspection of each head everything looked good!

FueledSoul

iTrader: (18)

(Port and polished)
I used a blue marker to color in the intake and exhaust ports, i put the gaskets on and made some scribes.



Intake, I started on the bowl areas, I knocked down the guide boss's and smooth them into a more free flowing shape.
I opened up the bowl areas a small amount keeping factory bias but just slightly enlarger the wider side and just cleaned up the shorter side.
I opened up the throat area, I knocked down the ridge and i blend the seats in. Next i worked on the intake runners. I focused mostly on the roof and flat runner walls. I opened up the push rod pinch slightly and gasket matched the ports. I left the floor and short side alone. i after running the carbide burrs i came back and hit the entire intake ports/bowls with 80 grit cartage rolls including the floor and short side.

FueledSoul

iTrader: (18)

Exhaust, I started on the bowl areas, I knocked down the guide boss's and smooth them into a more free flowing shape (More aggressively then the intake guides). I opened up the throat area, I knocked down the ridge and i blend the seats in, i barley touched the bowls i just cleaned them up, the bias i slightly enlarger the wider side and just cleaned up the shorter side. I left the port size alone and ran 80 grit cartage rolls until all the rough casting and factory marks went away. I went back over everything with 120 grit rolls, followed by a cross buff, buffing wheel and polishing compounds to give the ports/bowls a mirror finish.

FueledSoul

iTrader: (18)

FueledSoul

iTrader: (18)

I spent a estimated 32 hours porting and polishing, and never nicked a seat


Parts and price list. . .

Fel-Pro Performance Z1284 - Fel-Pro Performance Intake Manifold Gasket Sets $22.95

SCE Gaskets 211187 - SCE AccuSeal Pro Exhaust Gaskets $18.32

carbide scrib $2

bluing AKA blue permanent marker $? (found around the house)

Air Die Grinder $16

4PC New 6" Long Reach Carbide Burr Bit Set $39.95

96826 Abrasives cartridge roll 52 Piece $21.99

Standard Abrasives 260013 - Standard Abrasives Cross Buff Kits $25.99

Small buffing wheels $? (came in a dremel kit)

Rubbing compounds $7

A total of $154.20 + whatever shipping and or tax was.

FueledSoul

iTrader: (18)

(Covering the 4 coolant ports)
I picked up a peace of 2"x12" or more 3/8" thick T6 6061 Aluminum flat bar cost me $2.50. I cut them out and shape them by hand this part sucked! i think i spent like 4 hours test fitting and shaping.
before i made drew up some templets i used a cartage roll to smooth out the ports casting knocking it smooth.










(Valve train)
Keeping it cheap and simple! Now good for 0.525" of lift

LT4 SB Chevrolet Valve Spring Kit
16 Valve springs P/N (12551483) / $36.95

GM Performance Parts SB Chevy LT4 Valve Spring Cap Kit
16 Valve caps P/N (10212808) / $18.33

SB Chevrolet Valve Lock Set, 11/32"
16 Valve keys P/N (24503856) / $9.89

GM Performance Parts LT4 SB Chevy Valve Spring Shim
16 Valve spring shims P/N (10212809) 24.64 (still have to order)

Fel-Pro QSS72861 - Fel-Pro Valve Stem Seals $19.95

COMP Cams 501-16 - COMP Cams Valve Seals $4.95

A total of $114.71 + whatever shipping was.


(Next steps)
Drill and tap the heads for the front coolant fittings.
Weld the 4 plugs in.
Deck the heads.
Drill out 4 new coolant holes from head gasket
soda blast the valves.
30 degree back cut on the intake and exhaust valves.
hot tank.
Flow bench.
lapping in the valves for reassembly.
Assembly / lubricants

Mathius

So ok.. I don't know a whole lot about heads, but I know about welding. How are you planning to keep those plugs in there? That area looks pretty thick.

I wouldn't have made them flush like that. I'd have either set them in recessed and weld the whole area on top and then sanded flush, or I'd have beveled the edges on them and welded the same way. Either way if you leave them flush like that I can't see you getting much penetration and then when you plane the area off you're going to eliminate most of the weld strength.

Also, there still seems to be a lot of carnage after you said you sand blasted those heads.

Mathius

Awesome-X

Looks pretty awesome, I can't wait to see the outcome

FueledSoul

iTrader: (18)

Im not done with them yet. I just posted a pic of the location of the ports that are being plunged with the two peace that were cut out
(there just siting on top). When im ready im going to bevel the edges and sink them into the ports about a 1/8th of a inch before there tig welded.

Carnage? i dont have any idea what your talking about.
I never said anything about sand blasting the heads, I soda blasted the chambers. There is zero carnage using soda media see: http://en.wikipedia.org/wiki/Sodablasting, If you go back up top and look you can see how nicely it removed the carbon build.

FueledSoul

iTrader: (18)

Thanks! i cant wait to get them on the flow bench

robertfrank

iTrader: (27)

This has been done before, I can't remember who did it but I believe there was no issues running these heads after the work was done. I look forward to the finished product

83 Crossfire TA

iTrader: (2)

Are you drilling the front of the heads for the coolant or are you going to try sealing everything off so you can have it going to the coolant crossover in a standard manifold?

FueledSoul

iTrader: (18)

I really thought about this for awhile, i have seen the original write up on the LT1 conversion in the magazine, they drilled out new coolant ports where the normal gen 1 heads had theirs. But after reading how they JB welded a tube in place it was doubtful and seemed risky... I picked up a set of lt1 heads on ebay 5 years back to see if there was another way besides doing a tube and JB weld... I ended up selling them and there went the idea of converting them. I think it would be hard to try tig welding a tube in there and get everything welded (probably why they JB welded them in). The 2nd thing i thought about was making a plate blocking off the top of the oil valley on each side were the ports would be open and plugging the bottom that's open then just opening up the intake side for a coolant port but i don't know if it would warp the heads or how well the oil would be able to flow back to the crank case. At this point with my 2nd set the bracket and pulley set up i have i shouldn't have any interferences which was one the concern when i bought the first set, but that's no longer. I plan on taping the front of the heads and running a RPM air gap i will block and weld the coolant ports so i wont have to run a remote stat then drilling the LT1 head bolt pattern for the intake.

83 Crossfire TA

iTrader: (2)

that's about what I figured... I've never seen the original, or any writeup on doing this (I'd love a link if someone has one), but it's not _that_ hard to do.

I wouldn't be surprised if you could make it work with an aluminum tube and some JB weld (or putty), but what a mess you have if it does spring a leak.

The fact is even with traditional SBC heads, you'll get better, more even flow and cooling by drilling and tapping the front of the heads for fittings and forget about the whole stock thermostat housing/coolant crossover, but it seems like I never get to work on anything that has the room for that, there's always something in the way.

FueledSoul

iTrader: (18)

All post the original article.
?

FueledSoul

iTrader: (18)

injdinjn

Dont know when that article was written, but

https://www.thirdgen.org/forums/tpi/...eads-gen1.html

Looks like the pics have gone MIA. Might try an internet archive search on that.

FueledSoul

iTrader: (18)

Yea iv seen that, i believe i saved all the pictures but id have to look.

injdinjn

Keep us posted on the progress.

iroc a 86 berli

looks good! you always do quality work mr.soul! were did you get those carbide bits for 36$ thats a deal!

83 Crossfire TA

iTrader: (2)

If you find them I'd be interested in seeing them also...

huh... now you have me debating finding a set or even considering trying to make the set of iron LT1's that I have work for something (it never looked difficult, but now it looks like it might be a better solution for a project that I'm working on than what I intended to do)

FueledSoul

iTrader: (18)

Thanks for the complement. $39.95 When you do it Ebay.... They work great never dolled up, helicoptered or got caked with melted aluminum. I believe these are the same one Eastwood sells and some other sources

FueledSoul

iTrader: (18)

When i get sometime i will look to see if i do. The down side to yours is there cast iron, even if you find someone that can weld cast, the thing is your going to want to have them pressure tested. If it fails then you'll going to have to have it welded then pressure tested again, and who knows were you'll be at when you get them decked, it can get very costly very fast.

FueledSoul

iTrader: (18)

I look a little bit here and there i found a few pics i had saved from that TGO thread, i swear i had saved that thread page by page anyway i also found more material relating to this conversion like where people were taping the front heads for coolant fittings. i can post it if anyone is interested. In all honeste once im done with this conversion there will be plenty of information for most to understand and fallow. Here is a link i found when i searched.

lt1 head and intake conversion to gen 1 sbc
http://www.fullsizechevy.com/showthr...d-on-gen-1-sbc

He gave up on them though.

FueledSoul

iTrader: (18)

btw, if i get some time this weekend i might try and CC the ports and a chamber to give me a rough idea on how much material was removed from porting and figure out my combustion chamber CC.

FueledSoul

iTrader: (18)

I got around to CC my heads (measuring the volume in cubic centimeters)
I only CCed one combustion chamber, intake runner and exhaust runner at random. I don't know what stock was but this is what i got after porting and polishing.

Combustion chamber: 54.250cc
Intake runner: 176.2cc
Exhaust runner: 67.775

Im not really focused on the numbers, but they look good. I know for a fact i could easily bump the Intake runners and Exhaust runners to 180+cc/70cc if i wanted to but i think the ports look great and these will work perfect for the motor there gong on.

As far as CCing goes its easy and you can do it on a budget i got some 12cc and 3cc syringes and a piece of plexiglass that was on sale. I picked this all up at fleet farm, i spent a whooping $5.97.

FueledSoul

iTrader: (18)

HOW TO CC YOUR OWN HEADS.

I cut the plexiglass in two shapes one for the circumference of the combustion chamber and one for the intake/exhaust ports, i drilled a hole in the plexiglass about the same size as the outer diameter of the syringe tip.




I used petroleum jelly around the ports and chamber being CCed. petroleum jelly holds the plexiglass against the surface tight and keeps it in place.
Make sure you push down around the jelly you can tell when the plexiglass bonds to the surface. don't over do it or when you push down it will end up in the ports or chambers were you are trying to cc. Make sure all your ports are clean before hand.





I originally leveled my heads but i found they don't need to be perfect because your going to chase around a few bubbles towards the last few CCs (sometimes). You may want an extra set of hands to help prop the head were need be while you add more liquid from your syringe, otherwise you can add a few drops in the drilled hole before it overflows then move the head around once the bubble passes the hole it will let the air escape while it picks up the added droplets its tricky, mess it up and you'll have to start over. You don't want any bubbles in the port or chamber you want the fluid flash against the glass and not overflowing out of the drilled hole. I used blue washer fluid you can use pretty much anything even some air tool oil would work great. NOTE: they make syringes in many sizes these were just the ones they had my local store (12cc, 3cc), some come with or with out needles if you have to get the ones with needles make sure you discard and depose of them properly! you don't need to go poking your self! another thing to add is some only show 3cc but you can pull the plunger back and pick up more liquid then what it shows on the gauge.



2010-11-07124153.jpg?t=1289192263

regal301

is it worth all the extra work for lt1 heads over a set of fully ported vortec's ?(other than the iron vs. aluminum)

runner size and flow are almost identical right?

FueledSoul

iTrader: (18)

double post

FueledSoul

iTrader: (18)

Here is some more food for thought.

Vortecs
"The maximum amount of valve lift before the spring retainer hits the valveguide seal is 0.530 inches. It is generally accepted that 0.060 inches clearance needs to be maintained between the retainer and seal (0.530 - 0.060 = 0.470 maximum valve lift). The Vortec heads, as they come with the large valveguide seals, are only capable of accepting a camshaft with a maximum valve lift of 0.470 inches." I'll add something else regardless if you were able to get over 470" of lift you still have pressed in studs. so you could either machine them for screw in studs or pin them.

LT1 heads have screw in studs factory and with the right springs can take over 550" of lift

Combustion chambers
LT1 54cc, angle plugs
Vortec 64cc, straight plugs

As far as Iron Vs aluminum
Shave an estimated 50lbs off with aluminum.
Iron heads take 2 to 3 times as longer to port then aluminum.

As far as costs or if its worth it that all depends on what your goals are.
If your not willing to do some mods and your running a cam under 450" of lift vortecs are for you. If your willing to put in some time and do some mods then its a simple answer. If you look at my posts iv included a parts list with prices. you can compare them to the assembled vortecs. i feel that my set is much better then if i bought vortecs. prices are also going to depend if your paying a shop to weld, machine, drill, tap etc.

The Vortec head uses the iron LT1 chamber, intake and exhaust port design.

regal301

understood,thanks for the info

robertfrank

iTrader: (27)

I would really like to try this conversion. I have a friend here in town that has a **** load of these heads in his garage. Just for the sake of asking, is there a prefered set of LT1 heads that flow the best? I know some one told me a certain set of aluminum LT1's were the way to go but I forgot the part number.

Z28cross-fire

Did you by chance have the heads flow benched? It looks like you might have gone a little conservative with the porting.

Doom86

I do agree it looks a bit conservative but the volumes are good for the valve size and anything much larger will need a bigger valve to make use of it.

They look good to me for the time you spent. It helps having a good core to start with, you don't have to redesign so much as fixing minor flaws.

Looks like a fun project

FueledSoul

iTrader: (18)

10128374 and 10207643 castings are best for porting, they have more meat on them.

12551561 these are the lighter castings better flowing (out of all the lt1 casting stock for stock supposably) but less material for porting do to GM enlarging the water jackets i believe.

10205245 not sure about these but there probably like the 561 castings.

I think there was also a special number for replacement service heads that GM used but i don't have my 4thgen service manuals handy.

FueledSoul

iTrader: (18)

Not yet, but they will be. Its a mild port job, no need to go over board they flow pretty damn good stock.

FueledSoul

iTrader: (18)

exactly.

robertfrank

iTrader: (27)

As far as the coolant tube, couldn't you use aluminum piping and weld it up? Like where you see in the article picture? I know that the hole there doesn't lead to anywhere majorly important. Or possibly drill the hole just enough to have the tube be almost a press fit then weld up the seam to deter leaks? Or another idea would be to drill the hole, thread it then insert threaded piping? that might work.

FueledSoul

iTrader: (18)

Rob, i touched this subject on post #13.
If you want to add to it feel free, i just don't think its all that possible to get everything welded 100%

FueledSoul

iTrader: (18)

Here is what i was talking about in that post. You wouldn't need to run a tube. But you can see how hard it would be to weld even a tube in such a crammed area.














If you were able to do all that then all you would need to do then is cut or drill for a gen 1 coolant port.

robertfrank

iTrader: (27)

Ahhhhh I see what you're saying now. The only other thing that I can think of would be to either find a way for the oil to flow around the tube back into the crankcase or make a small tube to run through the coolant tube thats big enough for the oil to properly drain down but small enough for it not to impede coolant flow.

FueledSoul

iTrader: (18)

I thought about that as well but at that point you would almost be better off starting with 8113 castings. you could leave it pluged with no oil hole the oil would just flow out the push rod areas towards the center but i would feel safer having them flow directly down closer to the rear drain backs to the crank case. But there is more of a benefit taping the front of the heads for a fitting anyway.

here is how some gen 1 heads flow back

cuisinartvette

Interesting. 25x intake and 190ish exh is possible with the stock LT1 valve thats plenty to make some good street power. Have some flow sheets I saved somewhere just gotta find scan and maybe Ill post em up.

Keep going.

FueledSoul

iTrader: (18)

Yea these heads flow well even stock. iv seen a ton of flow numbers for these heads even stock ports with a change of valves (2.02/1.55) can enhance these pretty well here is some numbers people have posted.

http://www.ls1tech.com/forums/lt1-lt...ds-flow-s.html

even a simple search in Google will yield a ton of pages with flow numbers.

If you want to share yours feel free to post them up

robertfrank

iTrader: (27)

I was thinking about the whole coolant tube issue and from what i guess it shouldn't be that much of a problem since the oil drains more towards the rear of the heads anyway.

FueledSoul

iTrader: (18)

That's true but if its blocked how many quarts will fill up the the heads before it flows down the closest push rod hole and as RPM's increases this will become greater since there will be tons of oil in the top end. In theory it shouldn't matter to much but in my opinion its much better to have a straight shot down to the back of the block... More oil in the pan less oil on the top end that's really what you want.

KiLLJ0Y

iTrader: (1)

ok so how do you bolt the intake manifold on to these heads..?? for instance a 92 TPI intake manifold? You would need to redrill the heads to accept the manifold... is that doable on the headS?

FueledSoul

iTrader: (18)

You can either drill and tap the lt1 heads for your intake pattern your using, or drill and tap the intake for the lt1 head bolt patten. No idea on a TPI intakes if theirs room, and no idea on the vortec intakes. Most if not all gen 1 sbc (pre and post) intakes should work once modified.

83 Crossfire TA

iTrader: (2)

Updates? Are you drilling the intake or the heads?

FueledSoul

iTrader: (18)

There on the back burner for now, I was planing on drilling the intake to match the angles and locations of the LT1 heads... but all see which is going to be easier once i get to that point