Blemished cylinder heads
 

I'm curious with all the talk about bargain cylinder heads this time of the year, I would like your answer to the following and embrace any comments with your thoughts or reasoning.

Saw the other thread and voted,

I paid extra to have Butler supply, port and prep my heads. While I had years ago, hand ported my old iron heads, swirl polished my own valves and assembled my own heads off HO racing’s handbook. I much prefer the piece of mind from having someone with experience assemble this stuff. I just wish they would have recommended better rocker arms. But I don’t think it was well known then, that PRW roller rockers were sub standard, For all those that bought them, I hope we don’t find out that Speedmaster heads are below par somehow.

I didn't answer the poll because it depends on the blem and the price. Cosmetic external blem, sure. Incomplete machining of some area, sure. Break through of some holes, sure. Serious casting flaw, NO. Machining too deep and into water, NO. So it really depends on the defect. Also, we need to be talking about a substantial price break, like 40%-50% off. 10%-15% off?, I will take a good one thank you!

I as well didn't answer for the same reason mgarblik mentions. A visual issue is quite different from one that could potentially cause an engine out issue.

I'm also not a customer anyhow, already having a set of KRE D ports. I'll be a customer for porting services only on those heads when I get there.

Hi Mike, I tried to be as clear as possible. The discount it stated in the question and the "blem" is the seats may not have enough press fit. It maybe a little confusing because the poll split my post into two separate threads.... I probably did something wrong posting it.

OK, I see how the post got split. My answer would be NO. The potential of a seat coming out keeps me up at night. The heads would have to be free. Then I would remove all the seats and replace them with ones with enough press. Catastrophic complete destruction of the engine is the only result I have seen from a seat coming out of a running engine. Only one time did I have a seat come out while an engine was parked. It was a Jeep Liberty 3.7L. A seat came out while parked and when restarted made a horrible racket when cranked to start. Caught it and pulled the head and fixed it with minimal damage. Only time I ever got lucky with a valve seat.

For me it probably depends on how much it would cost to fix the 'blem' and if that puts the cost of the blemished heads anywhere near the price of a set of good ones then for I'd probably pass on them.

Threads are very confusing.

One thread says the seat is too tall and part of the side wall of the seat is exposed to the flame front.

Another thread has a different situation called a BLEM.

A third thread (assume due to the poll) has other opinions.

Just saying.

How many have actually owned a set of these heads and had them inspected?

Tom V.

Go over to classicoldsmobile.com where one of the builders claims to have sold 550 pairs of Speedmaster's Olds heads and find one post where someone claims a seat has fallen out. You would assume with even a 1% failure rate on valve seats, the forums would explode with naysayers. Bad gas travels fast and all.

Have to agree with your post 62posbonny, a VERY LARGE AMOUNT of miss-information out there.

Tom V.

Tom,I already posted my set went to my machine shop and he is very anal.They heads were pressure tested,inspected and found to have a crap valve job.Also the valve springs were at 150 on the seats for hyd roller cams BUT they had like a .900 coil bind.He did a valve job and will change the springs when im ready to use them in a build.Tom

So in reality:

A) Your guy is very anal (which is a good thing).
B) Heads passed Pressure Check and Inspection.

Now the interesting info:

Who set up the heads for you for the Roller Camshaft, etc initially?
Assume it was not the supplier of the heads unless they offered a Hydraulic
Flat Tappet Camshaft head and a Roller Camshaft head which seems unlikely,
so a third party was involved who did the initial assembly of the heads,
and also the crappy valve job.

AND APPARENTLY YOU PLAN ON USING THESE HEADS DOWN THE ROAD.

Sounds typical for work out there and the need to check everything BEFORE
you bolt them on the engine.

Am I correct, Tom S?

Tom V.

I bought fully assm heads a year ago,they were setup for hyd rollers.I have never built a round port head engine.Will do one this year,need pistons ,rods,rockers and lifters.He did not hate the castings.Tom

I've seen several pairs of Speedmaster/ProComp cylinder heads for the Oldsmobile engines. None of them had the casting flaw in the valve bowl area that might cause a valve seat issue that we are seeing in the Pontiac castings. I'm not suprised to hear there haven't been any reported failures or concerns.

Have any of them the Olds guys had complaints with those heads? I know the Rocket guys don't have a high opinion of them.

The major complaints the Olds community has had are the same complaints you see for most assembled aftermarket heads. Weak valve jobs, bottom of the barrel springs that aren't really suitable for anything, bad valve guide clearances and cheap valve seals. Buying bare heads and assembling with quality parts and light machining makes them more than servicable.

Interesting, so how much would the additional machine work cost? To correct those issues and assembley of the heads (assumming a shop does all the work)?

Vs. Buying the a set of assembled edelbrocks?

And for the guys like me changing from d ports to round ports would mean new headers as well.

If you have to aluminum weld up 8 seats and do all the required machine work you would be FAR better off to pony up and buy E heads.
If you have to weld on a new head, once you are done welding and machining its no longer a new head.
And with all those steps the potential variables/problems would be to me, mind numbing.
The guy better know what he is doing and that usually means not cheap.
Code for, buy E heads.
But If you want to put some decent springs on them and a good valve job then run them as cast, knock your socks off.

I was just curious what it would take. I have no interest in these heads at all. If I upgrade to aluminum heads I am looking at Kre d port ones. I'm not too fond of sending money to China and prefer to send it to (smaller) US based outfits to help keep them and the hobby alive. (perhaps the next post will disappoint me and tell me the Kre heads are also chinesium)..

I have not seen the defect so very hard to estimate the cost to repair it. Generally, if the press fit is just not tight enough, the old seats can be cut out and a .010" oversize OD seat ring can be pressed in. This may require a small clean-up cut in the counterbore for the seat. If the seat area OD is compromised, and there is not enough material under the seat for the new seat ring, then welding has to happen. Welding paper thin cast aluminum is difficult and the difference between the weld and the heat treated aluminum base metal is not the same. All in all, as soon as you start welding on an aluminum head, it is compromised from that point forward. I would say at a bare minimum, removing 16 seats from an aluminum head, replacing them, performing a valve job and blending the bowls, would take a full day of work with a manual machine like I have. Sunnen seat and guide machine. Cost of seats about $15.00 each. So $250.00 for seats. About $800.00 labor. Minimum $1000.00 That's no welding and no other issues. That's why it is a total loser of an idea. Start with good heads and sleep at night. If the manufacturer says their seats may be loose, they have had an issue. Otherwise, why would they say anything? BTW, KRE heads are cast in Ohio, USA.

List of important features in an aluminum head in order, IMO
1. Make sure damn seats will not fall out
2. Make sure guides have proper fit and are concentric with the seats
3. Make sure there are NO THIN areas or inclusions, pockets, or porosity in the casting.
4. Make sure all drilled holes, threaded fastener holes, drain backs, spring seats are accurately located
5. Use quality raw material and heat treat
6. Make sure the head flows as advertised
7. Use premium parts, valves, springs, locks, retainers. (not that important because you can buy bare castings)

Seat integrity is #1 for a reason. .