SP Heads

[louisb]

What is about the max engine size and HP you can make with a set of single port heads? Say for a 74 X 88 motor with a mild cam. (w100 or w110) I am just kicking around some engine ideas today and was wondering what you could really do with a set of single ports that were maxed out. I know they wont match a set of DP heads but could you maybe get close to 100hp with a set of SPs? To me is sounds like it would be a fun around town engine but top end would probably be very limited. Say 5000 - 6000 rpm max maybe?

--louis

[Lids]

you might need to halve you rpm limits!!!!  wouldn't the problem be getting the right fuel air ratio for this engine size on SP heads.

[louisb]

So you think the rpm would be that limited. Well, it was just a flight of fancy anyway. A set of DP heads with 40x35 and a mild port would probably produce more power and be cheaper anyway.

--louis

[louisb]

I was just trying to think of something different than your run of the mill 1776 or 2007 etc. Of course there are probably reasons those are run of the mill engine specs.

--louis

[besserwisser]

I just built a sweep the floor motor with single port 1600 , a radical cam ,46cc heads with retired race springs and a Holley bug spray. It runs okey but has a big flat spot due to an intake with plenum. Reving is no problem. Will change tomorrow to an intake with separated intakes. If all goes well we will know next weekend at Swedish Dyno Day what a motor like this put out. I will of course drive it there and home,5hours one way.

[louisb]

It will be cool to see your results.

I probably need to quit with the odd ball engines lol. I just have a bad habbit of starting down a road, like hopping up my 1500, and taking it to an extreme and ending up in engine bizzaro land. 


--louis

[Sarge]

Ported & Polished single ports with large valves = stock dual ports.  Back in the old days, before dual ports became common, you HAD to do those things to single ports.  Nowdays, there's dual ports and IDA's...what you NEED!    my 2 cents...

[louisb]

Ported & Polished single ports with large valves = stock dual ports.  Back in the old days, before dual ports became common, you HAD to do those things to single ports.  Nowdays, there's dual ports and IDA's...what you NEED!    my 2 cents...

Yeah, I think so too. I need a second job to pay for them too. 

Speaking of, crusing the Samba today I think I saw four or five sets of IDAs up for sale w/ a going price of $850 without much action. (A set I was watching a few weeks ago finally sold for $650.)  I guess with more folks going turbo or FI IDAs are losing some popularity. Humm turbo SP motor, oh wait never mind. (IDFs seem to be coming back down to earth too.)

--louis

[Sarge]

There he is!!! 

What's with the  ??    would have been a better choice...

[Donny B.]

One of the best engines I ever built was a 1600 single port with an Engle 100 cam.  It had stock heads (needed better springs) solid rocker shafts and swivel feet.  Stock carb for a '66 was all I had.  No kidding it would hit 6100 in first and second and boy when you hit second it would step sideways.  I was floating the valves like crazy and it showed when I had Dean Lowry redo the heads, but it sure was fun.  It ran a little hotter than I would have liked but if I had an 5-speed then I could have embarrassed a lot of folks.  I have the 5-speed now and intend to build that engine one more time.  I will however use CE modified heads with equal length studs and better valve springs and retainers.  It was a fun engine and I put a lot of miles on it.  What is left of it is in a bus running around the San Jose area.  Oh, and it was fully balanced with a counterweighted crank and 8 dowels.  Good memories last a long time!

[nicolas]

that W 100 cam seems to be a hot ticket if you want a torquey, lot's of street fun, small engined car. i know people who swear by that cam

[John Rayburn]

I remember a few type 3's around 80-81 that ran the 100 and they were real stump pullers.

[dyno don]

single ports heads rock !!.....and they do work much better on smaller engine applications as i had many a racer headhunting me down in the 70's at the vw bug ins as well as the vw drag days with larger engines than my 1600 and could not even come close to performance...my particular application was: 1600/non c/w crank/engle 120/1 3/8 exhaust with single muffler/s/p heads with sock valve size ported/polished with single h/d springs shimmed .060 on the intakes and .030 on the exhaust with a set of early kadron carbs..match raced several racers of notoriety and many with 48's and gave ALL a run for their money !!...first in my stock 67 with stock 4:37 that lived for years until a near fatal car accident in 77 then moved on and up with my first notchback and same combo with 148 third and 114 forth...drove the living crap out of this engine as my day driver getting over 40MPG and running almost 14's in the quarter mile(15:01 best) with street tires...could do easy 60ft burnouts and would often bet the big boys that no one could catch me first three gears....still have a signature set of s/p's in my garage with hopes to again tear up the streets/track...they work great when upgrading to 40x35 as well ...by the way when the engine came apart after 60k miles for inspection the case inside looked absolute bitchin'..no abnormal wear whatsoever..this is just a fine example of proper comdo and parts as well as proper maintenance......peace/dyno don

[Sarge]

single ports heads rock !!.....and they do work much better on smaller engine applications as i had many a racer headhunting me down in the 70's at the vw bug ins as well as the vw drag days with larger engines than my 1600 and could not even come close to performance...my particular application was: 1600/non c/w crank/engle 120/1 3/8 exhaust with single muffler/s/p heads with sock valve size ported/polished with single h/d springs shimmed .060 on the intakes and .030 on the exhaust with a set of early kadron carbs..match raced several racers of notoriety and many with 48's and gave ALL a run for their money !!...first in my stock 67 with stock 4:37 that lived for years until a near fatal car accident in 77 then moved on and up with my first notchback and same combo with 148 third and 114 forth...drove the living crap out of this engine as my day driver getting over 40MPG and running almost 14's in the quarter mile(15:01 best) with street tires...could do easy 60ft burnouts and would often bet the big boys that no one could catch me first three gears....still have a signature set of s/p's in my garage with hopes to again tear up the streets/track...they work great when upgrading to 40x35 as well ...by the way when the engine came apart after 60k miles for inspection the case inside looked absolute bitchin'..no abnormal wear whatsoever..this is just a fine example of proper comdo and parts as well as proper maintenance......peace/dyno don

WOW!!!  I think we struck a nerve here...hey, while your standing there, pass me a beer, will ya!      Thanks for the memories!

[Diederick/DVK]

wow, did you get a big time pro porting job on the the heads done?
or just the straightforward porting on s/p exhausts?

i'm thinking of an engine as such for my brother, this way he could use a lot of my old parts...

[dyno don]

actually the heads were hand ported with a dremel tool/can you say WARM HANDS...LOL...basic as in anything else...match port top of intake/dont take too much material from the "roof area"in the intake area/stock exhaust port/BLENDING is the key here...stainless valves a must with a strong single spring and (i had) titanium retainers...8:5 compression works well and can go higher depending on your fuel of choice ....>.sarge, was that a COLD beer??  LOL

[John Rayburn]

Hey Dyno, how are you? Have missed seeing you around the old cruise nights! Got one coming up, I hope you'll come around!

[christophe]

I just built a sweep the floor motor with single port 1600 , a radical cam ,46cc heads with retired race springs and a Holley bug spray. It runs okey but has a big flat spot due to an intake with plenum. Reving is no problem. Will change tomorrow to an intake with separated intakes. If all goes well we will know next weekend at Swedish Dyno Day what a motor like this put out. I will of course drive it there and home,5hours one way.

Here is a pic from today.
Besserwisser on his way out of the garage with his SP heads/Holley motor 
Good luck next week-end!

[Shubee2 (DSK)]

need to let the Floor Jack Down  

[christophe]

 

[louisb]

single ports heads rock !!.....and they do work much better on smaller engine applications as i had many a racer headhunting me down in the 70's at the vw bug ins as well as the vw drag days with larger engines than my 1600 and could not even come close to performance...my particular application was: 1600/non c/w crank/engle 120/1 3/8 exhaust with single muffler/s/p heads with sock valve size ported/polished with single h/d springs shimmed .060 on the intakes and .030 on the exhaust with a set of early kadron carbs..match raced several racers of notoriety and many with 48's and gave ALL a run for their money !!...first in my stock 67 with stock 4:37 that lived for years until a near fatal car accident in 77 then moved on and up with my first notchback and same combo with 148 third and 114 forth...drove the living crap out of this engine as my day driver getting over 40MPG and running almost 14's in the quarter mile(15:01 best) with street tires...could do easy 60ft burnouts and would often bet the big boys that no one could catch me first three gears....still have a signature set of s/p's in my garage with hopes to again tear up the streets/track...they work great when upgrading to 40x35 as well ...by the way when the engine came apart after 60k miles for inspection the case inside looked absolute bitchin'..no abnormal wear whatsoever..this is just a fine example of proper comdo and parts as well as proper maintenance......peace/dyno don

Now you have got me to thinking. I just picked up a set of kads. There is a CW 69mm crank on the samba for $60. Maybe a stock set of 85.5s to bump up the size to 1600. A set of those $75.00 rebuilt SP heads I saw with a hand port & polish job. A 110 with my 1.25 rockers I have coming. sounds like it could be a fun motor.

--louis

[besserwisser]

Drove the car down to JPM last weekend and ran it on the dyno. I had no big hope for major horsepoweras I wasn´t too impressed with the Holley Bugspray. Was guessing around 65hp. JPM really tried to get some rpm out of it but I think the long intake with single port heads are very limiting. Max was 60hp but I´m sure it was running very lean on top so with bigger mains maybe we could have reached 65. The positive part is that the motor has a lot of torque and being three people in the car with tons of luggage was no problem at all. Next test will be with two type 3 pdsit carbs on single manifolds before I switch to dubbelport heads.The big problem with the Holley is the switch from idle to accelaration.  Even though I changed to separate intake runners the motor has a BIG flat spot. Considering that a Holley bugspray is more or less a Stromberg 97 from the thirties it did make some horsepower but it mainly works at full gas. As with all centermounted carbs idle with cold motor is a problem. the preeheat tube just doesn´t cut it. I am sure though with some more carb work and increasing the acc-pump one can make this work better but for now I´m done with it.

[Zach Gomulka]

Now you have got me to thinking. I just picked up a set of kads. There is a CW 69mm crank on the samba for $60. Maybe a stock set of 85.5s to bump up the size to 1600. A set of those $75.00 rebuilt SP heads I saw with a hand port & polish job. A 110 with my 1.25 rockers I have coming. sounds like it could be a fun motor.
--louis

I think the 1.25 rockers would go to waste on a mild SP, JMHO 

[nicolas]

Now you have got me to thinking. I just picked up a set of kads. There is a CW 69mm crank on the samba for $60. Maybe a stock set of 85.5s to bump up the size to 1600. A set of those $75.00 rebuilt SP heads I saw with a hand port & polish job. A 110 with my 1.25 rockers I have coming. sounds like it could be a fun motor.
--louis

I think the 1.25 rockers would go to waste on a mild SP, JMHO 

that could be a waste, but on my small 1641 i switched the stock rockers for a set of 1.25 and noticed a difference. it worked on my engine with the w110. it may not be the best investment regarding horsepower, but it makes it more 'peaky'.

[Zach Gomulka]

that could be a waste, but on my small 1641 i switched the stock rockers for a set of 1.25 and noticed a difference. it worked on my engine with the w110. it may not be the best investment regarding horsepower, but it makes it more 'peaky'.

Was your 1641 a dual or single port?

[nicolas]

ah yes, mine is a dualport. that can indeed make a difference 

[louisb]

I have been talking with dyno don about this motor and come up with the following specs.

88 x 74
W120 cam
Ported and polished SP heads, stock valves
8.5 comp
1 3/8 header w/ dual QPs
Kads

I picked up a duel relief case yesterday. The kads and SP manifolds are on order. I am looking for a 74 crank now. I think this motor may be good for maybe 100-110.

I will use the 1.25s for now with the kads and header w/ single QP to pep up the 1500.

--louis

[louisb]

It also depends on the rest of the comb. If the stock carb and/or stock exhaust are used I doubt they would help much.

When I build this motor I think I will see if I can get some dyno time to really see how it does.

--louis