Singh Groove Test Engine – the Real Power Moves

[David Vizard]

The 306 that we built to test the Singh grooves was just that - a groove tester. It consitued a really nicely done to race tolerance specs bottom end with a spot on balance job and a set of ICON forged 10.5/1 pistons.

My intent here was to sell this engine as soon as the groove tests were in the bag. Well my Partner in crime Terry Walters, had other ideas. Terry found it difficult to sell a motor with a well prepped short block with a set of stock (other than the Singh grooves) heads and valve train. He commented somewhat pointedly that Walters Engines was in the business of selling real performance engines and as such this only constituted a performance orientated short block. Well I sorta had to agree on that.

Terry’s idea was that we put in a properly speced street cam, some roller 1.6 rockers and install bigger valves in the heads along with a minimal bowl cleanup (this will get some easy air without a load of porting work).

So here’s the deal:- The cam that we dyno tested on was a stock GT item which Jonesey measured out on his Cam Doctor to be a 268/268 (at 0.006 tappet lift) duration cam on an unbelievable erroneous 115.5 degree LCA. (for what the heads were this actually needed to be right around 105-106 – we just have to ask who was doing Fords cams at the time????)

The intent here was to replace the cam for one of the same duration but with more lift and on the correct LCA for the stock head equipped with the bigger valves. The cam then was to be a 268 degree single pattern deal on a 108 LCA. This means it had 52 degrees of overlap compared to the stock cams 37 degrees. By any standards the overlap on both of these cams is pretty minimal so no problems with idle vacuum or idle stability. In fact for those of you that may plan on replicating this build you could just as well go a few degrees bigger here and still have a totally streetable driver.

If you look through Jonsesy’s profile library it will tell you that the 268 profile #HR67325 has 218 degrees of duration at 0.050 compared to the stock cam’s 210 and lifts the roller tappet 325 thousandths instead of 278. From this we can get a fair idea that this profile is quite a lot bigger but not so aggressive as to outpace the stock lifters capability so long as a wise spring choice is made. And that turns out to be the case. I have run Mikes 268, 272, and 284 profiles in this series with checked out but otherwise stock lifters and have had stellar dyno numbers every time but back to the plot in hand here.

I have never been a big fan of Fords rocker systems especially the type on our GT test motor. These are to be replaced by a set of Proform 1.6/1 rockers.

Since this motor is expected to make its extra HP by mostly a sizable increase in torque the valve springs that would be needed would not be outlandish. All that is required here is a quality spring (that means less mass because the wire is better) and a little more seat pre-load and we would be good to go.

Now the big question here is how much torque and HP will it make in it’s upgraded form. Remember from the Singh groove report I said that in that form it made 347 lbs-ft and 306 hp. This was achieved with the use of a set of 10.5/1 Icon pistons , an Edelbrock Performer intake with heat isolated runners (underside fully insulated which produced the same intake temps as an air gap) , a 650 QFT vacuum secondary carb and the dyno headers.

So here is the question that I am sure is on most folks mind – what will it produce with the mods Terry is going to do to it??

As of now the dyno test is still over a week away and I am going to send Chad Speiers my guess as to what I think it should produce. Chad will reveal the accuracy of such when the results come in. Meanwhile I would, for the shear heck of it, like for you guys to guess what it will make. I will donate a signed copy of my cylinder head book (runaway best seller on the subject) to the closest answer.

So guys go for it.

BTW Terry will be covering a fair portion of the upgrade costs here so this engine will be a great deal for anyone wanting a true street performer.

DV

[RevTheory]

I'm guessing you'll sneak up on 350 hp with about the same amount of torque that you have now at probably the same peak torque rpm or possibly 300 rpm sooner. I know guys are scrambling through the inputs on their software and I'm just shooting from the hip. Just put my check in the mail

[Old as Dirt]

WAG.. with the "minimal bowl work/larger valves" and .048" more lift/ 15* more duration.. 384 Tq./ 358HP....

[David Vizard]

I'm guessing you'll sneak up on 350 hp with about the same amount of torque that you have now at probably the same peak torque rpm or possibly 300 rpm sooner. I know guys are scrambling through the inputs on their software and I'm just shooting from the hip. Just put my check in the mail

Mr. Rev Theory sir,
Think about that torque figure. We are opening the intake valve soon enough to have a good opening throughout the rest of the induction so the engine should inhale more air ie better VE. Also we are closing the valve sooner so the amount of air trapped at valve closure will be higher and that should lead to quite a bit more torque - wouldn't you say????

Maybe another guess is in order but there is a limit - (200 max!!)
DV

[David Vizard]

WAG.. with the "minimal bowl work/larger valves" and .048" more lift/ 15* more duration.. 384 Tq./ 358HP....

For what it's worth I think your WAG is pretty good but there again I only guessing at this point too.
DV

[prairiehotrodder]

375 hp and 390 torque. The right cam is gonna make a huge difference.
Brian

[user-612937456]

360 HP/ 372 TQ

[psychomotors]

375/375

[Carnut1]

397hp-403tq Torque curve very flat between 2500 to 5000. Great little street engine! If at all possible please flow these heads. I am figuring 1.94/1.6 valves and about 215 cfm intake and 156 cfm exhaust. Thanks Charlie

[Casper393W]

375 lbft. 358 hp

[midnightbluS10]

365/380

[DanE2]

I'm with Carnut, I think he is very close.

[Stan Weiss]

David,

5175 Peak Power RPM

369 HP - 410 Torque

Stan

[Old as Dirt]

With the right cam and some head work.. I could assume it would pick up 80HP.. nice little daily.. probably pull down 22mpg on shit gas if the tune is right.. love these guessing games..

[one finger john]

Same heads, same grooves ?

John