Engine overhaul

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tuscanlazers

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I'm looking to do a top end rebuild on my 94 tbi 350. I'm only finding heads for 1000 a piece. Would I be better off buying a performer intake for a carb and using a adapter and buy more reasonable heads? I have found an Edelbrock performer tbi intake for 200 so that's kinda the route I'd like to go. I guess my real question is can someone tell me my head options for my tbi 350? I can't seem to find reasonably priced heads that aren't remanned swirl port heads.
 

Schurkey

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TBI heads have the center two intake manifold bolts at a goofy angle. This complicates intake manifold fitment and selection. I looked at hogging-out the bolt holes of a stock TBI manifold to fit the older-style heads where all six bolts go in at the same angle, and I wasn't adventurous enough to grind the manifold. Seemed to me that there was not enough aluminum there to retain strength. Other folks have done that and gotten by with it...but I don't know how and they didn't post photos.

Going the other way--the older-style manifold on the TBI heads--is fairly straightforward.

If I were going to put replacement heads on a TBI short-block again, I'd order a pair of TBI replacement heads from Summit (Made by Trick Flow). $1100 per pair, assembled (but not in stock.)

I actually installed different Trick Flow heads on my K1500; but that required an older-bolt-pattern intake manifold that I had to adapt to TBI. Getting the EGR to work was a genuine pain in the asp. Not something I'd want to do again. The Summit heads are the easy way out.

Enginequest had cast-iron Vortec-style heads but with exhaust crossovers (for EGR) and the TBI bolt pattern on the intake face (CH350G). I bought a pair, but then sent them back as I didn't like the variation of valve-tip heights. I was probably being too picky; if I had it to do over again I might have used the Enginequest heads instead of the Trick Flows, and saved a heap of trouble getting the carbureted intake manifold to work with the TBI accessories.
 

eran tomer

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is it that simple for a john doe manufacturer to fabricate cylinder heads from scratch?
 

PlayingWithTBI

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If I were going to put replacement heads on a TBI short-block again, I'd order a pair of TBI replacement heads from Summit (Made by Trick Flow). $1100 per pair, assembled (but not in stock.)
I used these heads, everything worked OK. The accessory brackets bolted right up to the front of them. The EGR ports are where they should be. I did get full roller rockers, Chromoly push rods (needed to work with the guide plates), and tall valve covers. You need to use a push rod length checker to get the rockers centered on the valve stems based on your set up.

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You can place your order for these heads and Summit usually ships close to the date they show on the page. I got mine a few years back when they were $999 plus I got $100 in Summit bucks so, I only paid ~$900 for the pair :waytogo:
 

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is it that simple for a john doe manufacturer to fabricate cylinder heads from scratch?
No, not really. There are multiple aftermarket cylinder head manufacturers, but they're hardly "John Doe" companies. They're small by GM/Ford/Chrysler standards, but it takes serious money to develop a head, let alone build the tooling and provide heat-treatment and machining facilities for volume production.

Companies don't advertise, but I think a lot of the aftermarket parts are designed/engineered, then subcontracted to companies that specialize in foundry work, not specializing in cylinder heads in particular. The raw casting maybe gets shipped to yet another company that does heat-treat, and then a third company that does machinework. The name printed on the box isn't the company that manufactured the part, but they paid the invoices for the other companies that actually did the work.

Not much different for forged cranks. Building the forging dies, finding someone with a big-enough forge to pound that much steel...and then taking the raw forging through the heat treat and machining process to make a usable part out of it would be hatefully expensive. Forged rods would be easier just based on the smaller size of the part to be made.

Way back last century--around 1992-ish--I looked into getting a reproduction aluminum intake manifold for Chevy 427 Tri-Powers cast for small-volume production. I was hoping that the folks who GM subcontracted to make the originals still had the molds and core-boxes and the other tooling. They could just pull that stuff out of storage, and pour me a hundred copies. Original, used manifolds were going for near $2K, and Holley was still selling the Tri-Power carburetors. I wound up with a packet of info from GM regarding the legal responsibilities of reproducing what had been GM part numbers/intellectual property; licensing fees, business plan and projected sales...the costs started at 20K before a single prototype manifold was poured, never mind getting the raw casting machined and put into a box. Needless to say, ten or fifteen years later someone else started selling those reproduction intake manifolds--I've heard they are poor copies, and made in China. And casting an aluminum intake manifold would be easy compared to casting and machining an aluminum cylinder head. Iron is even worse. The metal is cheaper, but the tooling costs more.

Getting a cylinder head manufactured and ready for sale is a major undertaking. An engine block would likely be worse.
 
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PlayingWithTBI

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Not much different for forged cranks. Building the forging dies, finding someone with a big-enough forge to pound that much steel
Ha Ha, "That much steel". A little story : When I was working for aluminum extrusion companies, a couple times one of our extrusion presses had a main ram failure. These presses were made in the 60's and 70's, most of the main rams were sand cast steel or iron, then machined and installed. The companies I worked for made it a standard to acquire 1 piece forged steel cylinders. The last one I did was too big for the largest forging company in the US and it was cost prohibitive to get one from Europe. So, we got a waiver from our engineering/inspection company, DNV out of Norway to make it a 3 piece forging, front platen, barrel, and end cap. Lehigh Heavy Forge in PA made the forgings, shipped them to RL Best in Ohio who welded them together. They had to keep them hot the whole time welding, went through 3 pallets of wire in 2 weeks. After they were done, DNV came out to inspect the welds with ultrasound and x-rays. The welds had too many inclusions in them even though they passed US standards, they didn't DNV's. It turns out their welding machine circuit board went out and didn't give a proper flow. They had to cut out the welds and start over.

Anyway, finally they got it done and shipped the "bottle" to us in Phoenix. Only $43,000 for shipping and $1,800 to unload the 83,000LB bottle.

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A 48" diameter by 88" stroke.
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Fun stuff, sorry for the high jack, anytime I hear about forgings I think of these projects.:biggrin:
 

eran tomer

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No, not really. There are multiple aftermarket cylinder head manufacturers, but they're hardly "John Doe" companies. They're small by GM/Ford/Chrysler standards, but it takes serious money to develop a head, let alone build the tooling and provide heat-treatment and machining facilities for volume production.

Companies don't advertise, but I think a lot of the aftermarket parts are designed/engineered, then subcontracted to companies that specialize in foundry work, not specializing in cylinder heads in particular. The raw casting maybe gets shipped to yet another company that does heat-treat, and then a third company that does machinework. The name printed on the box isn't the company that manufactured the part, but they paid the invoices for the other companies that actually did the work.

Not much different for forged cranks. Building the forging dies, finding someone with a big-enough forge to pound that much steel...and then taking the raw forging through the heat treat and machining process to make a usable part out of it would be hatefully expensive. Forged rods would be easier just based on the smaller size of the part to be made.

Way back last century--around 1992-ish--I looked into getting a reproduction aluminum intake manifold for Chevy 427 Tri-Powers cast for small-volume production. I was hoping that the folks who GM subcontracted to make the originals still had the molds and core-boxes and the other tooling. They could just pull that stuff out of storage, and pour me a hundred copies. Original, used manifolds were going for near $2K, and Holley was still selling the Tri-Power carburetors. I wound up with a packet of info from GM regarding the legal responsibilities of reproducing what had been GM part numbers/intellectual property; licensing fees, business plan and projected sales...the costs started at 20K before a single prototype manifold was poured, never mind getting the raw casting machined and put into a box. Needless to say, ten or fifteen years later someone else started selling those reproduction intake manifolds--I've heard they are poor copies, and made in China. And casting an aluminum intake manifold would be easy compared to casting and machining an aluminum cylinder head. Iron is even worse. The metal is cheaper, but the tooling costs more.

Getting a cylinder head manufactured and ready for sale is a major undertaking. An engine block would likely be worse.
that's why i'm beeing scheptic about those heads and if they aren't actually manufactured in china.
 

Hipster

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that's why i'm beeing scheptic about those heads and if they aren't actually manufactured in china.
Alot of products are coming out of China to the point that some of the big name companies lower level castings are also import castings. You really have to be thorough in your research and possibly bypass the catalogs and call the company you're considering. Playing with Tbi is happy with his heads and probably the route I would go. If I was looking for a top shelf head I would be on the phone with Air Flow Research ordering exactly what I wanted along with their cam recomendations based on what I was trying to accomplish. I have used them several times in the past.

There's different levels of quality coming out of different foundries in China. Some is better then others. What looks the same isn't. On example in certain applications is Scat crankshafts vs. Eagle Cranksharfts. In those applications the Eagle's are a disaster waiting to happen.
 
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Schurkey

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Summit owns Trick Flow. Older Trick Flow head castings were made in USA. Summit still advertises the Summit-branded (Made by Trick Flow) TBI heads as "made in USA".

Of course, "made in USA" is subject to loopholes, exceptions, work-arounds. The lawyers have made sure of that. Good chance the valves are imported, no promises on springs, retainers, keepers, valve seat inserts, etc. However, I'd trust that the castings are made/machined in the USA until someone proved different.
 

tuscanlazers

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Hey guys sorry I totally posted this and forgot. I'll look into those heads Schurkey posted. But tbh I'm thinking about going a different route with the truck. I want a lot of upgrades that a 2500 would have so I may get rid of the 94 ex cab long bed in lieu of a single cab or ex cab short bed 2500 then build myself a 350. Plus I'm about to start a new job so things are going to be hectic for a moment. I appreciate the input though.
 
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