Rolling road... Good news Bad news
Discussion
Hi everyone, I took the Westfield to the rolling road yesterday to have the carb set up, but had problems, when the guy was setting it up it became apparent that there appears to be a problem with a couple of exhaust valves not closing properly, the guy had a pyrometer which when he pointed at each primary on the exhaust it showed that cylinder 7 was 100 degrees cooler than the rest a sign of a valve not seating properly. So it looks like a top end rebuild for me 
The good news was we decided to do a power run anyway we came away with 193bhp at the engine with 198lbs of torque at 5.1 and 163bhp at the wheels, which was pretty good as it wasnt running at full health and we didnt even touch the carb, so we should be able to crack the 200bhp easily when all is well, its gonna be expensive though unless I tackle the rebuilt myself hmmm.
The good news was we decided to do a power run anyway we came away with 193bhp at the engine with 198lbs of torque at 5.1 and 163bhp at the wheels, which was pretty good as it wasnt running at full health and we didnt even touch the carb, so we should be able to crack the 200bhp easily when all is well, its gonna be expensive though unless I tackle the rebuilt myself hmmm.
What carb setup have you got on there? A temperature disparity reading off the primaries can indicate many things, usually it's throttle balance but if you've got a single carb that's unlikely to be an issue though. By far and away the best way to check valve seating is with a compression test and whilst you're getting that done you may as well do a leakdown test too.
Out of interest which rolling road did you use?
Out of interest which rolling road did you use?
Gather it's a V8 if it's No7 playing up, but I'm not sure whether you have hydraulic or mechanical lifters/tappets. The temperature reading on No7 certainly indicates that it may not be firing properly, but before ripping the heads off, it would be worth a few basic checks first. Aside from checking the compressions for evenness across all the pots (expect a little variation) combined with a leak down test, check the integrity of the timing/ignition/plug gap, and the valave clearances/lifter operation - you should be able to do the latter just by removing the valve cover rather than the head - worth checking as an insufficient valve clearance or a stcky tappet not returning properly could give the same symptoms as a damaged valve/seat.
MG Mark
MG Mark
boosty said:
What carb setup have you got on there? A temperature disparity reading off the primaries can indicate many things, usually it's throttle balance but if you've got a single carb that's unlikely to be an issue though. By far and away the best way to check valve seating is with a compression test and whilst you're getting that done you may as well do a leakdown test too.
Out of interest which rolling road did you use?
Hi Boost its a four barrel Holley,Coltech said they would have a quick look and let me know what they think is wrong. Out of interest which rolling road did you use?
The rolling road I used was T&M in colchester, the guy really knows his carbs.
tankerman24 said:
Hi Boost its a four barrel Holley,Coltech said they would have a quick look and let me know what they think is wrong.
Hmm, in that case get them to do the compression and leakdown test, I'd also pull no7 plug and check the HT lead and state of dizzy cap just in case it's a simple problem there.Latest update today I took the Westfield to Coltec Racing
:- Compression test on all cylinders.... No faults
leakage test to problem cylinder ......No fault
test for hydrocarbons in coolant...... no fault
Went through everything even simple things like the leads going to the right cylinders, eventually found the spark to be orange and very weak and the advance on the distributor seems to be faulty/worn, They recommended that I have a conversion to electronic ignition and have the distributor overhauled, So im going to call H&H Ignition solutions who converted my last distribitor to electronic.
Im so glad that it appears that I wont have to remove the heads
:- Compression test on all cylinders.... No faults
leakage test to problem cylinder ......No fault
test for hydrocarbons in coolant...... no fault
Went through everything even simple things like the leads going to the right cylinders, eventually found the spark to be orange and very weak and the advance on the distributor seems to be faulty/worn, They recommended that I have a conversion to electronic ignition and have the distributor overhauled, So im going to call H&H Ignition solutions who converted my last distribitor to electronic.
Im so glad that it appears that I wont have to remove the heads
tankerman24 said:
They recommended that I have a conversion to electronic ignition and have the distributor overhauled, So im going to call H&H Ignition solutions who converted my last distribitor to electronic.
Top guys - get a huge thumbs up from me for the work they did converting my triple carb equiped Monza to conventional electronic distributortankerman24 said:
Went through everything even simple things like the leads going to the right cylinders, eventually found the spark to be orange and very weak and the advance on the distributor seems to be faulty/worn, They recommended that I have a conversion to electronic ignition and have the distributor overhauled, So im going to call H&H Ignition solutions who converted my last distribitor to electronic.
Glad to hear that it's something simple and pretty much what we said it was likely to be. T&M get a black mark in my book - the idea of a valve seating problem was pretty far fetched and they really should have been able to diagnose a simple ignition problem like that.Rather than just overhauling your dizzy why not ditch it altogether? The cost need not be any greater and the benefits are great. Email me offline if that's of interest to you.
boosty said:
tankerman24 said:
Went through everything even simple things like the leads going to the right cylinders, eventually found the spark to be orange and very weak and the advance on the distributor seems to be faulty/worn, They recommended that I have a conversion to electronic ignition and have the distributor overhauled, So im going to call H&H Ignition solutions who converted my last distribitor to electronic.
Glad to hear that it's something simple and pretty much what we said it was likely to be. T&M get a black mark in my book - the idea of a valve seating problem was pretty far fetched and they really should have been able to diagnose a simple ignition problem like that.Rather than just overhauling your dizzy why not ditch it altogether? The cost need not be any greater and the benefits are great. Email me offline if that's of interest to you.
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