Holly Carb Problem - Help!

[mike h]

Evening all,

Broke down yesterday and had to call the RAC out due to Holly carb not functioning, i.e. would not start. Those of you who have got Holly carbs, have you had this problem? The Holly carb is a 390, standard plate - both purchased from Tony Hart. Have not got a 7 degree adaptor plate on and I wonder if this will help the situation. It seems that I have got 'heat soak' [if that is the correct phrase]; has anyone tried to insulate the carb to stop the 'heat soak'. I have also got stainless steel tubular manifolds, Holly fuel pump and regulator. Any help/advice would be appreciated in this matter. Many thanks.
[If I don't reply to any response it is not that I am being rude but I have to get up very early in the morning, i.e. 2.30 am] Mike

[stagmuffin]

hi mike , I run a 390 on a modded inlet manifold with tubular headers and std fuel pump I also have had to install a fuel pressure regulator /filter combined( good bit of kit malpasi ) run at 3.5psi and use a 25mm thick phenolic spacer . I don't have these issues but used to when giving it the beans this cured it .I do not use the 7 degree adapter either but have no issues so I would suggest that you employ the phenolic spacer first you will need to change the studs .this stuff is available on the bay or from real steel.
Steve

[Stagdad]

When i had mine with a holley and took it to the power challenge at Enginuety it cut out after full throttle on the rolling road.It wouldn't restart so i left it for a while then it started fine,just boiled the fuel i guess.
Cheers Steve

[73stagman]

As I understand it the Malpasi Filter regulates the pressure between the carb and the filter. The fuel is cooler due to the larger volume of fuel in the filter bowl filling any heat related voids before the float chamber in the carb empties thus starving the engine of fuel. The Holley is desperate for fuel pressure and so the malpasi fixes the vapourising! Sure hope this one works!
343.jpg

[mjheathcote]

I've Tony's kit and the first things I did were the following:

1. Opening up the original inlet manifold to match the adapter plate to two full half moons for max flow.
2. Insulated 7 degree wedge plate.
3. Dump auto choke for manual conversion (never connected, a couple of pumps gets her going when cold)
4. Replaced secondary jet plate for one with screw in jets.

Been faultless was the last 19 years!

[Seaking]

Mike
what did you use to Insulate the wedge plate please

Glenn

[stagmuffin]

I've Tony's kit and the first things I did were the following:

1. Opening up the original inlet manifold to match the adapter plate to two full half moons for max flow.
2. Insulated 7 degree wedge plate.
3. Dump auto choke for manual conversion (never connected, a couple of pumps gets her going when cold)
4. Replaced secondary jet plate for one with screw in jets.

Been faultless was the last 19 years!

mike the secondary jet plate this is the quick change one yes ,what size jets did you run and who supplies the plate .
steve

[mjheathcote]

Moroso phenolic spacer if I recall correctly, it's been around 7,000 sleeps ago!

[Seaking]

Thanks Mike

[mjheathcote]

What size jets....

i jetted it it down from what I received from HRS, it was running far too rich, thick black sooty exhaust tips.
All the mods I bought from Real Steel.

The screw in jets from the primary, I put in the new secondary plate, and fitted smaller ones in the primary.
So 49 in the primary (that were originally 51 I think) and the 51's then into the new secondary jet plate.

i've a wideband O2 sensor in the exhaust and it appears fine, if anything maybe a little lean on the motorway when cruising.

Should really have had it rolling road tuned but I've seen no point with me ultimately going EFI.

[MissMoppet]

If you can, get it to Bawdrip S/Station near Bridgwater. He knows all about Holley carbs - and Stags - he's rebuilt more than a dozen of 'em.

[mike h]

Just like to say thank you to all who replied to my 'Holly carb - help!'; I very much appreciate all your advice. I have telephoned Darren from Bawdrip S/Station in Bridgwater as advised by Miss Moppet and I am hoping to take the Stag up and try and get the problem sorted out once and for all. I can change my oil and/or water but, sorry to say, I am not mechanically minded and really do not like dealing with any problems which involves petrol. Let's hope all gets sorted out. If I do breakdown on the way up I am in the RAC and in which case they will have to put the car on a loader and take me up to Darren's.

All the best to those who replied to my query - many thanks!

Mike

p.s. I will let you all know how I get on at a later date.