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138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 8:20 am
by kevin61
AMAZING!

We purchased an S4 DHC a couple of years ago (a fortune was paid for it as it was a stunning example of Mick Millers work). Sadly the engine had been seriously 'miss -treated' and damaged since its rebuild in 2006, being fastidious about the car we decided to bite the bullet and commission a 'new' sprint engine.

Given this was clearly going to be a major expense we researched various engine builders and spoke to many. We decided to take advantage of Vulcan Engineering (based at Brands Hatch), we could not be happier with our choice!
Steve Curson (who runs V E) provided us with straight talk sound advice and a wealth of experience, Steve and his small team are passionate about their work (dare I say "proper old school no BS guidance!) this was only surpassed by the ongoing communication and advice.

Our requirement was straight forward; a powerful but drivable new twin cam but had to remain 100% true to the original Sprint spec/parts . Steve relished the challenge, he was specific in what was needed to be done and what was needed to be spent but what also impressed us was that he was equally as clear where money was not needed to be spent . The head was declared serviceable but in need of machining/porting/polishing etc. and the carbs were declared serviceable with a rebuild - the rest NEW!

Throughout the entire rebuild process we were supplied with some 140 photos and videos of the strip down, new parts, machining and rebuild and the final photos of a fresh new twin cam was stunning as was the final product!!!

The 138.9BHP was way beyond our expectation - we were hoping for the late 120's so you can imagine our delight yesterday when going back to the rolling road for Steve to apply his final magic dust matching the timing and carburation to the manifold - even Steve smiled (a somewhat rare facial gesture I will wager [sorry Steve :D]).

For anyone that is passionate as we are about twin cam as we are, we cannot recommend them highly enough.
Vulcan Engineering
105-106 Brands Hatch Park
Scratchers Lane
Fawkham
Kent
DA3 8PH
01474-874689

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 9:11 am
by elanfan1
That?s nice to hear - post up some photos!

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 10:14 am
by Peter +2
Pm sent

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 10:31 am
by kevin61
Photo of engine ready for install

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 11:04 am
by kevin61
The new block machine and ready for build, block under build and machine pistons fitted

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 12:28 pm
by 2cams70
Interesting. What is the compression ratio? Looks very high for a road engine judging by the picture of the piston top. Looks like it is running close to zero deck height too.

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 5:41 pm
by Hawksfield
Hi

where did the block come from it looks different to an original lotus block?

Re: 138.9 twin cam new build

PostPosted: Thu Mar 07, 2019 6:33 pm
by richardcox_lotus
Looks like a new Ford block.

Did you have to remove the engine from the car or can they do that for you and keep the car on site?

Regards
Richard

Re: 138.9 twin cam new build

PostPosted: Fri Mar 08, 2019 7:02 am
by rgh0
kevin61 wrote:AMAZING!

.....
Our requirement was straight forward; a powerful but drivable new twin cam but had to remain 100% true to the original Sprint spec/parts . Steve relished the challenge, he was specific in what was needed to be done and what was needed to be spent but what also impressed us was that he was equally as clear where money was not needed to be spent . The head was declared serviceable but in need of machining/porting/polishing etc. and the carbs were declared serviceable with a rebuild - the rest NEW!



A nice engine and a nice outcome but it does not appear to be a sprint specification build "true to the original Sprint spec/parts". You can build great Twink engines in the 140 to 180 hp range suitable for the road and this looks like one of them. But its not a Sprint engine IMHO..... it is much better than that.

cheers
Rohan

Re: 138.9 twin cam new build

PostPosted: Fri Mar 08, 2019 7:31 am
by el-saturn
nice engine!! those accralites (?) are smiling thru the bores: that's what makes the visible difference! sandy ps - those domes look untouched -- is there enough clearance?

Re: 138.9 twin cam new build

PostPosted: Fri Mar 08, 2019 8:40 am
by kevin61
It is true sprint spec'd parts that have been used and is an original new ford block, Vulcan Engineering did and amazing job with the porting and polishing and the cams are sprint spec.

Re: 138.9 twin cam new build

PostPosted: Fri Mar 08, 2019 9:26 pm
by Elan Peter
I think I'm in love, beautiful job! I bet you can't wait to get the car on the road!!!! :lol:
Best regards, P

Re: 138.9 twin cam new build

PostPosted: Sat Mar 09, 2019 7:13 am
by rgh0
kevin61 wrote:It is true sprint spec'd parts that have been used and is an original new ford block, Vulcan Engineering did and amazing job with the porting and polishing and the cams are sprint spec.



Nice pistons but not true Sprint spec with higher compression ratio. The cut outs are for bigger valves as well. With good porting, a higher compression ratio, 83.5 mm bore in the new block and the right carb and exhaust mods and timing tweeking on cams and ignition on the dyno then around 135 to 140 hp is possible with a Sprint cam. A modern high lift short duration cam would get another 20 hp with the mods done already with better torque across the whole rev range.

cheers
Rohan

Re: 138.9 twin cam new build

PostPosted: Sat Mar 09, 2019 4:36 pm
by Davidb
Rohan, Would replacing just the intake cam with a modern, high lift, short duration cam have a worthwhile effect?

Re: 138.9 twin cam new build

PostPosted: Sun Mar 10, 2019 1:15 am
by rgh0
Yes for a road engine just the inlet is critical I believe. The exhaust flow on a twink is actually to great in most circumstances and restricting it a little versus the inlet generally gives better torque without losing any top end power. I have never tried it but a 285 degree 0.42 to 0.44 lift inlet with a standard sprint 272 degree .36 lift exhaust should work well.

My current race engine has a 300 degree .46 lift inlet and 285 degree .44 exhaust and it gives around 180 hp with 11:1 compression on 98 Octane unleaded pump fuel.

cheers
Rohan