Preliminary dyno results

[69gmachine]

I've had my engine out for some repair that I couldn't do; the lifter bores were too loose and one of the lifters was beating itself to death. The engine shop tore it down and did a light hone on the cylinders (.002), put in a fresh set of piston rings and sleeves in all the lifter bores to bring the tolerances in to spec and true them up. After putting everything back together, they ran it on the dyno to dial in the tune. I've always wondered how much I was giving up by using the Torker II instead of the Vic Jr... NOT MUCH! The peak HP was 537 and peak tq was 516. For comparison purposes it was dyno'd without any parasitic accessories such as an alternator or PS pump. That's all the info I have at the moment. They called me at the end of the day to give me the good news. I'll get all the details when I pick up the dyno sheets with the engine on Thursday.

I've been rather grumpy lately with no car and plenty of nice weather. They've had it for almost 9 weeks now, and I've missed car shows, club cruises, and open track events. I gave up on a high performance driving school Memorial day weekend because I don't think I'll have time to get everything sorted out. Once I get it back on the road I'm sure I'll forget all about the recent misery!

 

[classic boost]

was it dynoed with the vic jr? if not, how do you know how much it isn't giving up?
nice #'s though.

 

[69gmachine]

was it dynoed with the vic jr? if not, how do you know how much it isn't giving up?
nice #'s though.

No, only the Torker II, but a nearly identical build 408 with a Vic Jr. made 552 with no accessories. See Steven Rupp's thread on his 408 dyno results..

 

[jasonn]

It would have been interesting to see back to back results. But nice build! What cam specs do you have??

 

[69gmachine]

The cam is a Comp Cams XE282HR. Gross lift is .565 I, and .574 E. Duration @ .050 is 232 I and 240 E, LSA is 112.

There were a lot of things I wanted to try, like different carbs and intakes. They took way longer than they told me so I started bugging them once a week. I went up there and got a little aggravated, so they didn't call me to come take pictures while it was on the dyno. I think they just want me out of their hair.

 

[69gmachine]

I picked up the engine after work today and got a chance to look at the data. Peak Tq occurred at 4400 rpm, while peak HP occurred at 5800.

BSFC ranged from .45 to .5 between 4000 and 5900 rpm. It didn't really trend in a given direction, but rather wandered around getting slightly leaner then fatter then lean again through that range.

Torque was 490 ft-lbs or more from 4100 rpm all the way to 5800 rpm. Power took a dive past 5900, but I expected that. I was pretty stoked with the very broad, flat torque curve.

He only ran it with my 735 cfm reissue 428 CJ carb (with no spacer). He had told me he would try one of his racing carbs, but we were both anxious to get this over with, so I don't mind. He also told me he would try different tunes on the carb, but the BSFC was in a pretty good range so I don't think he messed with it. I had put larger jets in the primaries before I gave it to him, so it was tailored for the application before running it.

 

[69gmachine]

Well I should have waited until I had the dyno sheet in my hands before I posted numbers. The info I got over the phone was close but not completely accurate.

Peak torque was 522.3 and occurred at 4900 rpm. There was a peak at 4400, but the second peak was slightly higher.

Torque was 489 ft-lbs or better from 4105 rpm to 5400 rpm.

BSFC ranged from .4 to .5 between 4105 and 5953 rpm (the limits of evaluation). It could use some fine tuning of the air bleeds to lean it out more evenly across the rpm range, but I'll save that for next year.

Avg Tq from 4105 to 5000 rpm was 500.33, with avg HP 434.02 in that same range.

He didn't know how to hook up the old 2 port emissions vacuum advance, and hooked both sides to ported vacuum. It caused the timing to wander because the vacuum advance was fighting itself. Had he called me I could have told him to plug the retard port (which is how I drive it; I only have it on for looks). As a result, he overcompensated on the total timing, setting it at 36 so when it drifted down it wouldn't drop too low. After I get it installed and the vacuum hooked up correctly, I'll probably back the timing down to 34 total (IIRC, this is where the AFR head likes it but I'll double check).

All this with a rebuilt duraspark distributor from Autozone with an original, used 40 year old vacuum advance can!

 

[brianj5600]

Good numbers! I ran a TorkerII on a 306 years ago with good results. I bought one for my 351w mainly for hood clearance, but it is good to know they are quite capable of making power.

 

[gsxrken]

You could use more cam and carb to really maximize those 205s. I have a very similar build but with the 185s and it makes 530HP and 515 peak torque. I'd say based on that, you have some gains to be made if you care to go after them. Wheelspin is wheelspin, though, so you may not be able to use another 40HP on the street anyway.

 

[69gmachine]

You could use more cam and carb to really maximize those 205s. I have a very similar build but with the 185s and it makes 530HP and 515 peak torque. I'd say based on that, you have some gains to be made if you care to go after them. Wheelspin is wheelspin, though, so you may not be able to use another 40HP on the street anyway.

I'm sure your right, but since this is primarily a street and open track car, I don't really need more power.

If I had an unlimited budget, I'd like to see what the 185s would have done. They may have been a better choice for my cam and carb, but I hadn't seen anyone try the 185s on a 408 when I bought my heads. Still I'm pretty happy with how well all the pieces worked together.

I had them machine the block for a one piece rear main seal while they had it, and also weld up a bung for a screw in PCV fitting below the carb in about the same place as the stock port would have been.

I dropped it in the car over the weekend, but there are still a LOT of things to hook up before it will be drivable.

 

[68GT500KR_Vert]

Who did you end up taking it to?

 

[69gmachine]

Who did you end up taking it to?

McKeown Motorsports Engineering. They went 350% over schedule (2 week estimate, 9 week actual) and 50% over budget, although they did perform work that was not in the original estimate at my request (convert to one piece rear main seal and welded up boss for PCV port). They didn't need to do all the work that was in the original estimate so that was a little bit of an offset, but not nearly enough. The worst part is they replaced my steel distributor gear with a bronze one. I had asked them to re-pin it as I had broken the pin off in the shaft. They could have drilled a new hole in the steel gear 90 degrees off and re-used it, and I also had a new blank steel gear I could have given them to use if they had asked. I don't know how long the bronze gear should last, but I'm planning on replacing it with a steel one. They also lost one of my spark plug wire clips that goes on the valve cover to add insult to injury.

I think I will buy a crate engine if I ever want another one.

I don't question their ability to build a good engine; they have placed in the top 10 in the engine masters challenge the last two years in a row. However I would give them an "F" on their communication skills, and another "F" for their inability to maintain anything close to a schedule. I had to contact them once a week to get a status, and it was always the same story "we'll get it on the dyno next week". Never once did they apologize.

 

[bnickel]

i can tell you from several other peoples experience with bronze gear and steel roller cam that it won't last long at all and is probably on it's way out already just from the dyno runs. swap that gear as soon as you can or you might wipe out your main bearings. just FYI, JohnPro on the VMF had this exact issue as did several other people i've heard from. BTW, what happened to using the C90X intake? did you give up on that or do you plan on trying out later? interested to see how it works on your 408 if you decide to use it.

 

[jerry S]

i can tell you from several other peoples experience with bronze gear and steel roller cam that it won't last long at all and is probably on it's way out already just from the dyno runs. swap that gear as soon as you can or you might wipe out your main bearings. just FYI, JohnPro on the VMF had this exact issue as did several other people i've heard from.

My mechanic here said the same. When he installed my steel roller cam, he told me to get rid of the bronze gear I gave him and get a composite gear instead. At over a $100, it was indeed spendy but it is well worth the piece of mind. He said it will also last longer than a steel gear so it is cheaper in the long run.

 

[69gmachine]

i can tell you from several other peoples experience with bronze gear and steel roller cam that it won't last long at all and is probably on it's way out already just from the dyno runs. swap that gear as soon as you can or you might wipe out your main bearings. just FYI, JohnPro on the VMF had this exact issue as did several other people i've heard from. BTW, what happened to using the C90X intake? did you give up on that or do you plan on trying out later? interested to see how it works on your 408 if you decide to use it.

Thanks for the info. I was hoping I could leave it in until next winter, but I don't want to take any chances with it. Now I have to get another distributor set up before I can start driving

I almost snagged a C9OX intake on e-bay but I was out-bid in the last 30 seconds. I was only willing to buy it if I could get it for a good price because it's not something I really need. I'll keep my eyes open for a good deal and someday I'll pick one up. I think I'll have to mill the divider down most of the way to make it work as well as the Torker II does.

 

[bnickel]

yeah prices on those things are getting ridiculous. i paid $180 for mine only 3 or 4 years ago. i imagine i will mill some of the divider on mine as well, but for now it's untouched and will likely stay that way until i build the long rod roller motor.