TRExp

Motorsports Forum

1500 build for 100HP-reliable for street

Moss Motors
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor

claytoncnc Avatar
claytoncnc Gold Member Marcus Clayton
Melbourne, Ivanhoe, Australia   AUS
In reply to # 1323219 by POLLYMARKA Are there any porting templates available for the 1500 heads?

Preshaped to use as guides in porting?

I have seen them for rotary engines.

Rotary engine ports also control timing, so they serve the function of a camshaft as well as inlet/exhaust tract. The purpose of the template is to get the timing right.
if you want good results from the Triumph 1500 engine, basically leave the ports alone, as they are already , if anything, too big. Just knock off any obvious dags, and do not polish them.

If you want to support more than about 100HP, then port modification is required, but it is almost all down on the Short Side radius, valve, valve throat and seat. The port can pretty much stay the same size.
You will need a really good exhaust, a well thought out intake, 9:1 compression+ and at least a 25/65 cam before you start thinking about these mods.
The 1500 engine is rev limited, so 100 HP is probably the practical limit, and the ports are big enough for that.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
bluecrab Avatar
bluecrab tom broring
Maryland, USA   USA
As noted above, the 1500 ports are pretty good size already. There is some benefit to gasket matching the ports. Using a stock manifold gasket placed against the head, you can see if any of the ports are smaller than the port hole in the gasket. Frequently some of the ports do not match the gasket because of the crude casting process that was used for most cylinder heads when these cars were built. Just focus on grinding within an inch of the gasket surface into the ports so the ports match the gasket better. On the exhaust ports there is a vertical lump of metal in the port that corresponds to where the head stud passes through the head. I like to reduce how much that area sits inside the port, although you don't need to remove 100% of that area.

When you have your valve job done, you should use a performance or racing machine shop. They will have tools that can do a 3 or 5 angle valve job which will help flow. Also, they will probably have a tool that can clean up the bowl area above the valve a little. These steps are cost effective. If the head you are starting with did not come with the 1.44 inch stock valves, that is an upgrade you can do when you are getting the valve job.

A full prep, ported race-type cylinder head would cost quite a lot of money due to the man hours needed to alter the ports. You would need to work with someone who has cut apart stock heads to see how much metal can be removed before hitting water passages-and they will charge for their knowledge. I feel this type of head would be overkill for your hp goals.

Poppa G Gary Wood
Morristown, TN, USA   USA
Take head to machine shop that has a flow bench. You need as much "clean" flow as poss. They can tell you if it is/ not flowinh to full potential, if not they can tell you what, how much, benefit, and where to go from there once you have max flow. And keep engine sound, strong, very reliable! Usually you get more h.p. an torque, than you ever though possible! MAKE ABSOLUTELY SURE IT IS A VERY!!!! Good, reliable shop, asking some, race car drivers can get you the PRO'S you want an need........hope this helps an gets you started on xtra h.p. an relibility!!!!

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
claytoncnc Avatar
claytoncnc Gold Member Marcus Clayton
Melbourne, Ivanhoe, Australia   AUS
In reply to # 1330681 by Poppa G Take head to machine shop that has a flow bench. You need as much "clean" flow as poss. They can tell you if it is/ not flowinh to full potential, if not they can tell you what, how much, benefit, and where to go from there once you have max flow. And keep engine sound, strong, very reliable! Usually you get more h.p. an torque, than you ever though possible! MAKE ABSOLUTELY SURE IT IS A VERY!!!! Good, reliable shop, asking some, race car drivers can get you the PRO'S you want an need........hope this helps an gets you started on xtra h.p. an relibility!!!!

Sorry ,
cannot in any way agree with that advice. ports flow plenty for 100HP. With standard size ports it cannot reach the 72m/sec velocity which is ideal for this flow regime. Bigger ports make it worse.
Clean up some dags, but do not enlarge.
Head work should be confined to short side radius, 3 angle valve job a subtle unshroud of the valves with a ball end cutter and at least 9:1 compression.
Racers know about race engine porting, this engine is to be tractable from 1000rpm and pull through to redline which is quite low on a 1500, and race porting would result in efficient breathing that starts near the red line, and quite compromised performance in the first 4000 rpm of the rev range.



Edited 1 time(s). Last edit at 2015-11-22 03:59 AM by claytoncnc.

hoffman900 Bob Adams
USA, USA, USA   USA
1978 Yamaha MC TT500 "Flat Tracker"
In reply to # 1330895 by claytoncnc
In reply to # 1330681 by Poppa G Take head to machine shop that has a flow bench. You need as much "clean" flow as poss. They can tell you if it is/ not flowinh to full potential, if not they can tell you what, how much, benefit, and where to go from there once you have max flow. And keep engine sound, strong, very reliable! Usually you get more h.p. an torque, than you ever though possible! MAKE ABSOLUTELY SURE IT IS A VERY!!!! Good, reliable shop, asking some, race car drivers can get you the PRO'S you want an need........hope this helps an gets you started on xtra h.p. an relibility!!!!

Sorry ,
cannot in any way agree with that advice. ports flow plenty for 100HP. With standard size ports it cannot reach the 72m/sec velocity which is ideal for this flow regime. Bigger ports make it worse.
Clean up some dags, but do not enlarge.
Head work should be confined to short side radius, 3 angle valve job a subtle unshroud of the valves with a ball end cutter and at least 9:1 compression.
Racers know about race engine porting, this engine is to be tractable from 1000rpm and pull through to redline which is quite low on a 1500, and race porting would result in efficient breathing that starts near the red line, and quite compromised performance in the first 4000 rpm of the rev range.

Disagree 100%.

Maybe by a black magic voodoo "expert" (ie: not one with a flowbench or clear understanding of engine performance), but anyone who does proper race engines (and they will be rare as hens teeth in the British car market) knows it's about power curve between two peaks. Even the drag racers... it's an acceleration contest, not a dyno contest. "Race engine porting" isn't a thing, ports sized appropriately for the intended use are.

A good head specialist worth his salt knows how to size the port for a given application. This may include of performing modifications that increase cfm, without increasing area, which will ultimately increase the velocity of what are typically too large ports. This will undoubtedly help a car in a street combination.



Edited 1 time(s). Last edit at 2015-11-24 08:13 PM by hoffman900.

claytoncnc Avatar
claytoncnc Gold Member Marcus Clayton
Melbourne, Ivanhoe, Australia   AUS
I have to wonder if you guys have read this thread from the start. I quote from the first post:

Looking for about 100 streetable HP, but something that is not going to grenade the engine......Lets get a modern recipe for a reliable performance 1500 that anyone can do and that will not cost an arm and a leg..
Then from post #3
Looking for a bump from stock without breaking the bank...

A Triumph 1500, carefully built to essentially mk3 Spit specs, with HS4s and a decent exhaust will deliver more or less 100HP, without significant head work, which comes at not insignificant cost. It is all too common to get a stage1,2 head, which hurts performance in a low RPM street engine such as this.
This is a recipe for a non exotic engine that can be built at home using stock inexpensive parts. Andy Martin followed this advice to the letter on another post, and he is thrilled with the result, all done at home, with almost no previous mechanical experience, and so far the most expensive item was the cam at about $200. The HS4s may have come in about the same.

Now I do not know where you are coming from Bob, but I do not quite see where we disagree, as you say, and I said, ports should be sized appropriately for the task. Bigger is not always better in fact flow can very often be sacrificed for turbulence which keeps fuel in suspension, or for cancelling or enhancing resonance to realise a torque benefit. As you rightly said, there are not too many places that can do that. But racers are the last guys to get a recommendation from as there is little regard for cold starting, idle quality, off idle response, smoothness of operation, low end, fuel consumption or durability. All these qualities will be sacrificed if necessary for midrange and top end power.


I have to take some offence at the voodoo black magic expert, if that was aimed at me.

I do have 3 dynos, and flow benches, and air consumption measuring devices, and a pattern maker, in fact I have a factory where we develop and manufacture engines for commercial sale.
They are industrial units, where it is a case of dial up your torque requirement, (the easy part), then work on the fuel efficiency, which drives the emissions away.
We cannot claim figures, we have to prove them, and they have to perform non stop 24/7 at 100% load if necessary.
I do not now make or sell engines for cars, racing or otherwise, but my own engines or those belonging to friends do end up on our Heenan and Froude, and 8000 rpm plus is not unknown in the evenings.

I can assure you that a flow bench is only part of the solution for anything other than flat out performance over a narrow rev range. It is a indispensable tool but it fails to account for the fact that air is bouncy stuff, and that the inlet and exhaust flows are not linear, but pulsed, one consequence of which, is that if you get air in more easily, at critical frequencies it can also come back out again , just as easily.

If you are interested, I can dig out some air consumption graphs that show this effect, a V8 high performance engine that consumed less air at 4500 than it did at 3500 rpm comes to mind.
We did the race tuning work under contract to TRD back when we did that sort of thing. The 4AG engine was breaking crankshafts at 8800rpm or so. We got on top of that when we found a travelling wave effect in the inlet manifold that was causing a high speed miss, which occurred at the resonant frequency of the crank. Fixing the inlet tract fixed the crank problem.

In EVERY case, whatever the engine type or RPM range, the lower the BSFC (Brake Specific Fuel Consumption) the higher the torque. How many people measure and quote that!



Edited 1 time(s). Last edit at 2015-11-25 12:38 AM by claytoncnc.

Speedracer Avatar
Speedracer Platinum Member Hap Waldrop
Greenville, SC, USA   USA
1967 MG MGB Racecar "The Biscuit"
I add this FWIW, on the Triumph 4 and even 6 cylinder heads the port runners themselves, are not that bad stock and if you port one of these heads for the street you really don't want make the port runners any bigger, that kills flow velocity. I always tell folks when you see a picture of the nice polished and ported head, it is what you can't see that makes the difference, and the same is true with the Triumph cylinder heads, sizing the bowl to the valve size you are using and radiusing the short radius (floor of the port leading into the valve) is where you'll see the most gains. Same goes for polishing the combustion chambers, wow it sure does look great in a picture, but offers very little gain. That's why I started offering my street port heads a few years ago, the whole idea was to offer a port job that concentrated on the most important gains, while it cut down on porting labor time and thus lessened the price of improving your head, it has worked out well, I do 25-30 street ported heads a year now.



Hap Waldrop
Acme Speed Shop
864-370-3000
www.acmespeedshop.com
Engines, Rebuild Kits and More.


Member Services:
MG/ Triumph Performance Street/Race Engines - Cylinder Head Porting - Modified SU HS Carbs - DIY Engine Rebuild Kits With Free Tech Advice - Alloy wheels for British Sport Cars,and others
Poppa G Gary Wood
Morristown, TN, USA   USA
Thanks hap. I just mentioned, good flowin head, not ported, race cc'd but i guess i should have been more low grade explanitory. Those guys didnt get me at all. You did it right!! Thanks again.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Poppa G Gary Wood
Morristown, TN, USA   USA
Oh,nother thang. Hap, be careful..they will 100% diagree an give you a voodoo name!!!! smiling smiley smiling smiley have fun, drive safe. Gary
Double certified
61 years young and ran 3 G- tech sbop for, cant count tbe years. Or many diff engines, heads, cranks and cams i fixed. And NEVER HAD A REDO!!

grumpicus Steve Jackson
Leicester, Leicestershire, UK   GBR
When you have only a few posts on this forum, you would be wise to determine who are the respected contributors with specific experience of small Triumph engines before posting anything even mildly disrespectful......



Edited 2 time(s). Last edit at 2015-12-01 05:58 AM by grumpicus.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
hoffman900 Bob Adams
USA, USA, USA   USA
1978 Yamaha MC TT500 "Flat Tracker"
In reply to a post by Now I do not know where you are coming from Bob, but I do not quite see where we disagree, as you say, and I said, ports should be sized appropriately for the task. Bigger is not always better in fact flow can very often be sacrificed for turbulence which keeps fuel in suspension, or for cancelling or enhancing resonance to realise a torque benefit. As you rightly said, there are not too many places that can do that. But racers are the last guys to get a recommendation from as there is little regard for cold starting, idle quality, off idle response, smoothness of operation, low end, fuel consumption or durability. All these qualities will be sacrificed if necessary for midrange and top end power.

Hi Marcus,

I disagree. Turbulence in the port is bad always. A rough texture provides some sheering action for puddles of fuel, but that's about it. It's the job of the shearing action of the valve angles (well, that's part of their job) - this is why radius valve seats may flow more but are slower and make less power, and the other is squish action. But that's about it.

The inlets on Triumph ports are generally too large. By working with the valve job, throat, and the short side radius, you can generally increase cfm without increasing area too much. This in turn will increase the average port velocity.

Keep in mind all engines have the same range where the ports will flow most efficient. The speed at which the engine runs will dictate the size - but a F1 engine running at 18000rpm will want (generally speaking) the same average inlet tract velocity as a Triumph peaking at 5600rpm - just the latter will require much smaller cross sectional areas.

A friend has one it arguably the fastest TR4 in the world - it starts better than most street cars - about 2-3 seconds on the starter and vroom. Everytime.

Quote: I can assure you that a flow bench is only part of the solution for anything other than flat out performance over a narrow rev range. It is a indispensable tool but it fails to account for the fact that air is bouncy stuff, and that the inlet and exhaust flows are not linear, but pulsed, one consequence of which, is that if you get air in more easily, at critical frequencies it can also come back out again , just as easily.

A tool is only as good as the operator. If the head specialist understands it's about balancing velocity and cfm, while reducing port turbulence and sonic choke conditions at a chosen peak power rating - whether that is 5600rpm or 8200rpm or 14,000rpm.

Quote: have to take some offence at the voodoo black magic expert, if that was aimed at me.

Not you, but speaking in general terms about the cottage industry.



Edited 1 time(s). Last edit at 2015-12-02 05:32 PM by hoffman900.

claytoncnc Avatar
claytoncnc Gold Member Marcus Clayton
Melbourne, Ivanhoe, Australia   AUS
Again Bob, I cannot see where you are disagreeing with me in any way, except for turbulence. I agree that angles are for shear, (I usually put an edge on the SSR as well).

Your examples are all about flow, and I cannot disagree with any of them if you are NOT experiencing charge robbing or standoff effects.
If you do see these acoustic phenomena, then either ignore them, and suffer the flat spot, or you fix them.

The (quite old now) graph shows quite clearly what I am going on about. The bottom graph shows air consumption at WOT rising with rpm as it should until it reaches just over 4 units @ 3000 rpm
By 3700 rpm the air consumption is only about 2.7 units, about the same as it was consuming at 2000 rpm.

On a flow bench, this does not show up, as the interference and reversion effects cannot be simulated.

The lack of flow is due to acoustic action and interaction of pressure waves, not to any port or valve limit.

The problem was solved by introduction of some controlled turbulence. which inhibited the pressure wave interactions, and the airflow ended up being far more linear up to about 5500 where it dropped off due to port limits being approached (which can be measured on a flowbench).
The flow regime with induced turbulence is not ideal, but the engine had a lot more area under the torque curve by the time we had finished.

Looking at the file, This was test 7A.
I have data for up to test 57 on day 8.

I do not remember it taking that long!


Attachments:
R V8 dyno.jpg    73.3 KB
R V8 dyno.jpg

Fictioneer Avatar
Fictioneer Doug Hirt
Colorado Springs, CO, USA   USA
All of this is way above my pay grade. smiling smiley



"Mr. Filby, do you think he'll ever return?"
"One cannot choose but wonder. You see . . . he has all the time in the world!"

claytoncnc Avatar
claytoncnc Gold Member Marcus Clayton
Melbourne, Ivanhoe, Australia   AUS
It is a bit of a laugh.

A recipe for something cheap and cheerful is what was asked for, and what was proposed in the first instance.

Kevin Joel Avatar
Kevin Joel Kevin Ferreiro
Mirandela, Bragan├ža, Portugal   PRT
Hello,

I want to buid a reliable for street 100hp Spitfire 1500.
I made a list of thing based on what is going on here and in the auskellian article but my knowledge is limited.
With thoose i have 4 main questions..
1-Will i reach the 100hp?
2-Will i maintain or improve the torque curve or will i loose in the low rpm? (based in my file. And i want to at least maintain to keep streetability)
3-Will it be reliable or eat it self up?
4-Do i need all of those thing or more/less? What i need or do not need from that list



Edited 3 time(s). Last edit at 2016-03-29 09:54 AM by Kevin Joel.


Attachments:
78' Triumph Spitfire 1500 Project Build 100-110.pdf    183 KB

. Hide banner ads & support this website by becoming a > Gold Supporting Member <

To add your reply, or post your own questions

Members Sign In   or   Create an Account

Registration is FREE and takes less than a minute!


Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster