Aluminum and Iron Head 455 Builts- Parts and power comparisions

Thought I would share the results of a number or recent builds, so we can compare and contrast the results of different builds, built by the same guy (me :TU: ) and tested on the same equipment (head flow and dyno).

Let's start with the basics..

74 STG 1

A true 455, built from An NOS shortblock assembly- fitted with TRW forged pistons in standard bore. Re-balanced and decks squared and cut to leave the pistons .032 in the hole.

Rebuilt stock 74 STG 1 heads- no porting, just a good valvejob.
Headflow- 218/139 cfm at .500 lift
STG 1 cam 210/223 degrees at .050
Iron manifolds- 73 intake and 74 exhaust- untouched
800 Q-jet, no spacers
9.3-1 compression

Idled, and performed exactly as I would suspect a later model STG 1 would, with increased compression (stock was 8.5)

Here's the numbers



Peak Torque was a bit lower, 451 at 2800 rpm
Peak HP 343 at 4700 rpm.

That's why you shift a stocker at 5000 rpm

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70 Standard valve Low Compression Performance rebuild (SF motor)

This is my Suburban motor, and I wanted to run it on regular unleaded.

Standard Bore with stock pistons (motor was in excellent shape)
Squared the deck with pistons at .040 in the hole.
9.1-1 compression (.040 head gasket, and opened up the head chambers)
TA 212 cam (218/230@.050)
Performer intake
800 Qjet
Iron exhaust manifolds
Stock Heads with light bowl and chamber work (220/150 cfm@.500)

Excellent idle quality, smooth and quiet- runs all day on reg unleaded.




We see an increase in torque and Power due to the camshaft- heads were very similar to the stock stage 1's used on the previous engine. Biggest thing we see here is the power curve difference- look at peak torque- 900 rpm higher. Although the curve is still very flat, with no loss in power at the lower rpm levels.

We added headers to this engine.. and the increase might surprise you..

Absolutely no other changes required, as the headers only leaned the engine out .3 %. 13.1 to 13.4, and our testing has shown time and again that a Q-jet wants to run right in there.. changing rods might have brought a number or two out, but nothing major..



It's important to remember that good motors are a combo of parts, and this result with just adding headers is a good example. I have seen these very same headers be worth 25 HP on say a 475HP engine. That motor is trying to flow a lot more air, and they help a lot more.

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Now, let's move to the ported head stuff..

First off

455/ported head low compression Performance rebuild


TRW pistons .050 in the hole .030 over
430 heads with street/strip port, small valve (270/170@.500)
9.4-1 compression
113 cam (228/247@.050)
Performer manifold 1" spacer
800 Q-jet
TA 1 7/8 headers

Now you see why everyone's first advice is "Port the heads".. A significant power increase over my truck motor, and what we would expect with ported heads and a bigger cam. The heads are really the biggest factor here, as the cam was selected to match the headflow, and attain the HP level we were looking for, which was 450 HP.



Good power increase, still using reg unleaded, or maybe a mid grade fuel.

Now onto the pump premo motors

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TSP Level 1 455

This is my base "hot rod" motor.. nice idle, good vacuum, great for your everyday cruiser.

You can see it here...

http://www.trishieldperf.com/Level 1 engine specs.htm

Very similar to the engine above, but a higher compression version.


.030 over TRW Forged pistons
Zero deck height, with engine re-fit (heads and block cut to match)
9.8-1 compression
288-94H cam (230/240@ .050)
Ported 69-74 small valve heads (250/180 cfm at .500) with CC'ed and reworked/polished chambers
Performer intake
800 cfm Q-jet
1-7/8 headers




What we see vs. the previous engine is the effect of higher compression with the torque difference, although somewhat muted by the fact that these motors don't have the hard to find, and crack prone big port 430 castings. You could port these heads more, and get into a set of STG 1 valves, for even more performance. But this is the head flow target for this level of engine that I selected, as it was attainable with the small valves and a reasonable amount of porting. Going to a full comp porting, and STG conversion really adds to the overall price tag. These days, we are money ahead to just downshift to Aluminum heads.. hence the creation of the Level 1A engine.. in a couple different forms
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I include the latest copy of this engine, to further illustrate the importance of the cylinder heads.

A word about aftermarket Alum heads..

I use TA heads on my builds, not because of some blind allegiance to TA, but because they are super cost effective with some bowl and chamber work, when you have to get to that 315/240@.500 cfm that is required to make the switch to the alum heads make sense, cost wise. Putting on 270 cfm aluminum heads simply doesn't get me to where we need to be, and I guess it's better than plunging that money into full port iron heads, but it's really the cost effectiveness of the headflow that I am after.. not so much simple brand loyalty. The TA heads work, and I don't think you can get to these numbers, to build a copy of this engine, with the same amount of money with the Ebrocks.. and I tell ya, roller rockers don't come into play here.. zip, zilch, nadda.. they are not required.. even though I spec'ed them with the 1AH engine, you really don't need them, I have tested, and they are not worth any HP.. They are just more durable, and easier to adjust with this level of engine.

TSP Level 1AX

A hybrid between the alum head manifold and header motors. It uses the AM shortblock, which is the basic TRW forged/stock rod, zero deck deal, but with cam changes to account for the use of headers.

This one is my most popular motor right now. Have a couple of these going at any one time, but let's talk about the one I just shipped to South Carolina here a few weeks ago.

Level 1 TRW shortblock, zero Deck
TA 310 cam (232/232 @ .050)
TA STG 1 SE heads with TSP bowl/chamber upgrade (315/240 cfm at .500)
10.3 to 1 compression
Worked Performer intake- no spacer
1000 HP Holley
1 7/8 headers


Nice Idle, with a slight chop-- 14" of vacuum with this one at 800 rpm.

Here's the numbers




And here's a pic.. I really like this engine, with the TA polished covers, painted heads with good bolts in the engine, and the Performer and Holley carb, it doesn't look much different than a stocker, but sure does make the power.. I have built them with stock STG 1 covers, stock plug wires and a Q-jet, and that's a really sneaky 490 HP engine..




One more engine to cover, and that's the max perf street compression iron head motor that can be built if your lucky enough to come across a set of ported STG 1 iron heads.. and there are plenty of sets of them around with the advent of the alum heads now..

All for now, let me know if anyone has any questions,and I hope this helps in selecting components for your build, and also in having reasonable expectations for performance.

JW

 

I love the info and comparisons Jim Thank you for sharing your wealth of knowledge!

 

Very informative, Jim. Those look like nice #'s! BTW, what is stock deck height on a 70 sf motor?

 

Jim,
When will you be posting the particulars on the max street performance compression, iron Stage 1 headed engine?
Thanks,
John L

 

Makes me wish I put another 10 hours into my heads with the die grinder!

 

10.570" is the typical deck height, some later blocks I have seen have been .010 or so more.

Almost without exception, the passenger side deck is .004-.008 taller than the driver side. That's where "squaring the deck" come into play.

If there was a good inexpensive forged piston that had a compression height .030 higher, it would make building a zero deck block with stock crank and rods a much more economical proposition. I typically have to cut anywhere between .035 and .055 off a block to zero deck it. And to do it right, you also have to cut both the end rails of the block to refit the seal, as well as the intake side of the cylinder heads. All of this cutting and test fitting typically adds up to about $300..

And every intake manifold is a little different, so while the formulas get you close, it's a spec fit to the particular parts and gaskets. I really like to run the .060 thick TA composition intake gasket, and we add that cut in accordingly in these engines.

JW

 

Thanks Jim ...this is all so informative to all of us ..I look forward to these type specific posts from you .....thanks for sharing this info ! Just for posteritys sake what do TA's heads average / flow right out of the box with no work ? Thanks J.

 

Thanks Jim - This info is great!

- Bill

 

Here is one person's experience plus JW's :

http://www.v8buick.com/showthread.php?t=130843&highlight=stock+TA+flow+box


http://www.v8buick.com/showthread.php?t=40258&highlight=stock+TA+flow+box

 

Here it is John... sounds like your still leaning toward more power for your buildup..

That latest version of my Level 2 iron head engine was built for fellow board member Ed Wilt (topless64455).

Here's the specs

.038 SRP pistons
786 Irons fully ported with STG 1 valves (280/200 at .500)
290-08H cam (238/248@.050)
Performer intake
TQ 1000 comp series carb
zero deck- 10.4-1 compression

Here's the numbers




This is potentially a engine that could require a mix of race fuel into pump premo, and certainly as far as you can push the cam timing, and still get the power brakes to reasonably function. I have found with actual on car testing, that a multi spark igntion box makes a world of difference in idle quality, and vacuum at idle speed. Rhodes lifters or a vaccum can can help out this issue, and I have in fact built several complete cars that we "got away with it" without them, and the only time the brakes were a bit of an issue was when starting it up and pulling out of the garage with the engine still cold. But everything has to be very specific, from the sealing of the cylinders to the carb and distributor tuning. If your off just a little with any of this, you can run into vacuum problems at idle.


A word on intakes..

Now, all these builds us a Performer, and in every case it's because the customer wanted to use his GS air cleaner, or wanted to maintain a more stock looking engine. This by no means should be construed to think that is the best intake to use. The simple fact is that to meet the requirements of stock looking or use of the ram air breather, the iron intake or the Performer is our only choice.

ON an engine above 400 HP, the TA Sp-1 will typically bring between 10 and 20 HP, on engines above 500 Hp, that can typically be 25+. I have also found that intake responds very well to a spacer, especially on the 500+ HP stuff, but that further complicates hood clearance issues. That intake achieves these HP numbers by raising the torque curve of the engine, while enhancing it overall. So don't assume that I shy away from a single plane intake, and let's look at a couple different engines that are a little more "off the grid" here. Both of these motors used the New SPX, which actually trades off about 10 ft lbs of torque in the 4500 rpm range, for and extra 10 HP at the peak HP level, which in these motors is right around 6000 rpm.

In 2 of these engines, the SPX style intake were actually KB cool runners, but the SPX is essentially the same, with some minor improvments, was used because they "looked Sexy"... and they certainly do provide a visual impact, beyond that of even an SP-1, if that's what your after. If you building 600+ HP, then the SPX is definately the intake for the job. The third motor actually was the SPX, and I tested the new SPX with a bit of work to a well modified KB cool runner, and the ran the same.

Every one of these engines uses upgrade con rods, a crygengically frozen block, or a short fill in the block, or a girdle. SFI flexplate and balancer, and the better TA 1611B SRP pistons at .038 over, with the superior 1/16 ring package. These are certainly a bit more expensive engine. These are also built from "select blocks" with thick cylinder walls and decks, and vitually no core shift.

First is the level 1 AH..

Still a street motor, that's pump gas and power brake compatable. Used where hood clearance is not an issue.

10.4- 1 compression
TA SE STG 1 or STG 2 Aluminum heads with at least 315 cfm thru the intakes at .500. The more the better, but no great advantage for one head or the other.
SPX intake (SP-1 a good choice also for this engine)
TA 288-92H cam (231-234 @.050)
1000 HP series Holley, with a 1" spacer
1 7/8 headers

Here's the numbers




This motor has an agressive, but not totally objectionable idle speed and quality. Very similar to the 310 equipped motor above as the specs are nearly the same, but the more airflow thru the exhaust of this engine likes the cam spread out on the exhaust side a bit. Loves the 110 lobe center.

Farther on here, we get to the 2A engine, right at about 600 HP..

Specs are nearly identical to the 1AH, with the exception of the following

Cam- More intake duration, several copies have been built with slightly different cams, but we need about 240* of intake duration, and they again respond to about 4* more exhaust duration than intake.

This particular engine ran the TA 298H cam- straight pattern, but we had some really good exhaust ports on this engine, as we were playing with the head flow and valve sizes on the exhaust side. These engines respond well to the 1.81 exhaust valve.

Here's the numbers




Still pump gas, and still streetable.. 900 rpm idle, and some assit on the vacuum brakes would be best here. Although this car didn't have it, and it was no problem.

This was installed in a 87 Regal, and it was scary.. hit second on the freeway at 60 MPH and punch it, and you fishtailing.. probably the only street car that has ever scared me. On the strip it has run in way into the 10's in street trim.


Now, if you throw the power brakes out the window, we step right up to a 308 cam. Built several of these engines for guys who wanted a seriously "bad" idle speed, and the right setup for the combo. A couple were 4 or 5 speeds and I can only imagine what that would feel like.

To push these engines past 600 HP, we have to do one of two things. Either run the cam duration out, or fully competition port the heads. All the good stuff is required on these motors, in the valvetrain if we chose the cam route. Now, in all of these instances, the customer already had TA roller rockers, so the choice was a no brainer, as the flat tappet cams cost the same, regardless of specs. And a fully ported, big valve aluminum head can get into a 4K process..

This engine is still a pump gas piece.. 10.6 compression
But with the big 308S cam (268/274@ .050)
TA SE STG 2 heads (330/260 cfm @.500)


Here's the numbers on this particular one..



We purposely pulled this thing from 3000 rpm, to illustrate the huge power band available.

A board member owns this one, and it's going in a 70 X with a 5 speed..

That's gonna be fun..

We started from the base stock rebuilds, and went thru a host of different combos, and I hope this helps you guys here get some good info on combo's, on the effects of compression, cam duration and gives you some real world numbers to reference to.

Let me know if you have any questions.

JW

 

Interesting.. I have never seen flow numbers out of the box that low on the TA heads.. Back in the day, we did several sets of "BPG special heads" that were done completely by TA, and we consistantly got high 270's to low 280's out of them, without touching the castings.

Every one of them, and every TA STG 1 SE head that has went thru here (about 25 sets now) has been treated to the bowl and chamber work. For not much more money, the heads really respond. Blending the seats in, working the short turns and opening up the chambers really turn these heads on. For 2795.00 a set of ready to bolt on Alumium heads, that use all your existing valvetrain gear, and flow past 310 on the intake is a great value. I don't touch the inlet or outlet of the heads, as there is no need. They are plenty big enough right out of the box.

And that's the real beauty of TA's heads.. they don't need excessive, time consuming full porting, to be high flow pieces. 90% of the port is good right out of the box, they need to be smoothed and contoured in the bowl around the seats, the short turn helps a lot, and chamber work really picks up the low lift flow numbers, which are very important.

And as we have seen, the heads are super important.. that's where you spend the money, and the very last place I'm going to recommend that you attempt to "save money".. as it will often lead to dissapointing performance.

JW

 

Jim, fantastic info!! Thanks for sharing:TU:

 

I must add if you think you can do the alum. chambers by hand it's very time consuming. I did mine with an old pair of valves, orange crush gaskets, dowels, dumores with different attachments and have yet to cc them to finalize the work. Quite a bit of volume is added to the chamber by this work. Now I will need the heads milled to raise the comp. where I want it.
When I purchase heads again I will definitley get the chambers done.
Ray

 

Ya, my bad... long post..

Fixed it, thanks for catching it..

And don't be afraid to try a 290H... as that would be a 10* intake duration advantage over your current cam, and only 1.5* more overlap than the 92H. If I recall correctly you have some deck on that block yet, so it should clear. While I generally will go with a smaller cam when someone asks me for a reccomendation, simply because it's easier for them to deal with, I think your savvy enough to make it work out.

Depending on your flow numbers on the exhaust side, it may or may not like an extra few degrees in the exhaust, but keeping that overlap down, while keeping the lobe center around 112, and running as much intake duration as possible is the key here, to making as big a difference as possible, for going thru the trouble to do a cam change.

Either cam is as far as you want to go with my 12" VP, but your in the ballpark here. Key is to get it to pull harder in the middle and upper ranges, to get your ET's down. Alan has a similar setup to you, and frankly, I wish I would have run that cam in his, instead of the 08H..

If it were me, I would put that 290 in, make sure I get my intake close number @ .050 to 45-47*ABDC, run about 25* inital and 34 total in your distrib.

I think it will be ok with your GV for cruising, and sound and manners will be very similar to the 92H. I like the idea of the more intake duration, would hate to see you go thru all the trouble, and not get that last tenth your looking for.

JW

And split 2nd with your GV.. keep it out of high gear as long as possible.

 

Oh boy the winter in MN must be really really harsh as JW is starting to see things........ou: :bla:

JW....you need to get a girlfriend.....they are much much much much much more sexy than the SP1 intake...........:Smarty:

:bla:

 

It's not really too bad, once you have done 5 or 10 sets.. :eek2: But yeah, the first set probably took me 3 times as long as it does now.

And getting them cut to size is no big deal, the raw castings have to be milled anyway. We just mill more to account for the bigger chamber. They pick up about 2-3 CC when I do them.

Here's what we are talking about here.. This shot was taken just before I set them on the engine, and you get a good look at the chambers, and the unported exhaust and intake ports ..



Those heads, on an SRP zero deck shortblock at 10.6 compression, with that 288-92 cam, and an SP-1/1000 HP made this power..

<a href="http://s150.photobucket.com/albums/s110/tspjim455/?action=view&current=clintD464.jpg" target="_blank"><img src="http://i150.photobucket.com/albums/s110/tspjim455/clintD464.jpg" border="0" alt="Photobucket"></a>

JW

 

Jim, I guess I'm looking to be somewhere between Tim and Ed's engines. It looks like Tim has a slightly better set of heads than I do. Mine are Stage 1 valves flowing an average of 260/183 at .500. We talked about going to a zero deck height so that would give me more compression? How much? I don't mind using premium gas but I don't want to have to go to race gas or a mixture. I'm ok with a more aggressive cam if it just means a little brake aggrevation at slow speed or when cold. Are my expectations realistic (somewhere between the two)?
John L

 

Jim, I know this question is going too head in a slightly different direction than the thread is going, but I wondered if you have ever tried taking a big port iron head and changing the exhaust valve to 1.75", but leaving the standard intake valve. It seems to me from looking at various flow numbers that the standard iron Buick heads need alot more help on the exhaust side than the intake side. I was wondering how well the flow would balance out on a street motor (below 500 HP) if most of the porting was done to get the exhaust numbers up, with just some bowl work in the intake side.
Have you ever tried it? Thanks for your reply, Randy

 

Here's my 1st attemp below. I'll combine it with a custom TA 296h cam. Cam card says 238@.050 but when measured was 246/243. From looking at the info. on the 2A 298h buildup I should port the exhaust.
Great information!
Ray