38 replies to this topic

[Retroman]

mmm, just come across your thread, I assume it has been on the rolling road...? Do you know how accurate the rev counter is ?

 

I would agree the 1.5 rockers are probably too much maybe some 1.4 forged ones would work better

 

what at 3200 sounds quite high, not sure how many cc you have and how the cam is timed, or what the cam LCA is but my old 999S would take what at 3200 with a 296 cam, and tickover at 12-1300.

 

Not sure the twin HIF 44's are such a good option for a Hillclimber, they are capable of suppling enough air for over 300 HP

I vizarded a pair the same size for a circuit racer and he gained 2.3 seconds per lap.

 

I think for a hill car a Vizarded single 44 or twin 1 1/2 vizarded with maniflds worked and matched to the head would probably gain some time and maybe pull the what down too.

[dotmatrix]

mmm, just come across your thread, I assume it has been on the rolling road...? Do you know how accurate the rev counter is ?
 
I would agree the 1.5 rockers are probably too much maybe some 1.4 forged ones would work better
 
what at 3200 sounds quite high, not sure how many cc you have and how the cam is timed, or what the cam LCA is but my old 999S would take what at 3200 with a 296 cam, and tickover at 12-1300.
 
Not sure the twin HIF 44's are such a good option for a Hillclimber, they are capable of suppling enough air for over 300 HP
I vizarded a pair the same size for a circuit racer and he gained 2.3 seconds per lap.
 
I think for a hill car a Vizarded single 44 or twin 1 1/2 vizarded with maniflds worked and matched to the head would probably gain some time and maybe pull the what down too.

hello and thank you for your reply :)

yes its been on a rolling road about once each year. no I don't know how accurate the rev counter is, I have a new tacho to go in at some point.
its a 1293cc engine, the LCA is 106 degrees as far as I can find out and the cam is timed in at 106 degrees.

my dual HIF44's are also partly vizarded.
I have actually vizarded and rebuild a single HIF44 and bought some manifolds to try out the single carb option on the rolling road, I didn't get time to do it the last winter, maybe I will have a couple of days free in the comming winter to try that carb setup out.

I actually don't use the revs bellow 4000rpm when racing so the car being unable to use what bellow 3200rpm doesn't bother me on its own.

[Retroman]

Sounds like a plan

 

I would have thought with a 106 LCA cam timed in straight up in a 1293 it should come on cam earlier, but as you say when on track revs are up anyway. Bear in mind the 2 44's are big enough in standard form to swallow enough air for 300 horses...too big for a 1293.

 

Not sure what manifolds you have but the MG Metro ones need work to get the best from them, a steel maniflow one should be the best option. Post the results on here if you can, its an interesting development.

 

[dotmatrix]

Sounds like a plan

I would have thought with a 106 LCA cam timed in straight up in a 1293 it should come on cam earlier, but as you say when on track revs are up anyway. Bear in mind the 2 44's are big enough in standard form to swallow enough air for 300 horses...too big for a 1293.

Not sure what manifolds you have but the MG Metro ones need work to get the best from them, a steel maniflow one should be the best option. Post the results on here if you can, its an interesting development.

Thank you for the info, nice looking carb:-)
I Will post the results but IT wont be done in a while.

I have a titan motorsport, a howley and a mg metro to try with a single hif44. The cast alu minispares manifold is also supposed to be quite good but i havent got one of Those.

Ok. I dont know anything about the maniflow Steel inlet for a single hif44.

Edited by dotmatrix, 22 June 2018 - 02:01 PM.

[Turbo Phil]

For a single HIF44 the Maniflow alloy inlet is the best I've tested so far. Better than the MG Metro even in modified form.
I picked up a Minispares one recently and should get round to testing that in the next few weeks.

Phil.

[hhhh]

Regarding the Maniflow inlet, has anybody compared it pre and post Vizard mods where some meat is taken out of the outer long radius just before the gasket face to relieve cylinder bias? The other Vizard mod of taking some out right at the top of the center doesn't seem necessary compared to some others I've seen where there's too much metal there.

[dotmatrix]

For a single HIF44 the Maniflow alloy inlet is the best I've tested so far. Better than the MG Metro even in modified form.
I picked up a Minispares one recently and should get round to testing that in the next few weeks.

Phil.

I did read about your tests previously. Very exciting. A flow bench seems like a wonderfull tool:-)

[Orange-Phantom]

Very interesting info on conical springs.  I must say that I'm very tempted after doing a bit of Googling about them.

 

To the original poster, I'm a bit surprised about the comments on 1.5 ratio rockers and the 296SP Kent cam combo.  My brother runs this combo on his race mini/hillclimber along with a Weber 45 carb with exceedingly good results.

 

In this years hill climb on the Isle of Man he won his class (again) and was the fastest mini by quite a margin.  He was even beating cars which really he shouldn't have!

 

Edited by Orange-Phantom, 23 June 2018 - 11:53 AM.

[Turbo Phil]

For a single HIF44 the Maniflow alloy inlet is the best I've tested so far. Better than the MG Metro even in modified form.
I picked up a Minispares one recently and should get round to testing that in the next few weeks.

Phil.

I did read about your tests previously. Very exciting. A flow bench seems like a wonderfull tool:-)

Yes it's certainly an interesting tool and useful to.

Phil.